Single-Tooth Implant [1 ed.] 0867157712, 9780867157710

Table of contents :
Single-Tooth Implant A Minimally Invasive Approach for Anterior and Posterior Extraction Sockets
Frontmatter
Library of Congress Control Number:2019943782
Contents
Foreword
Preface
Chapter 1: History and Rationale for Anterior and Posterior Single-Tooth Implants
Immediate Versus Delayed Tooth Replacement Therapy
Clinical Example
Challenges with Immediate Implant Placement
Classification of Extraction Sockets
Diagnostic Aids for Socket Management: Radiographic and Clinical Examination
References
Chapter 2: Management of Type 1 Extraction Sockets
Flapped Versus Flapless Tooth Extraction: Evidence-Based Rationale
Tooth Extraction Techniques with Specific Instrumentation
3D Spatial Implant Placement Within the Anterior Extraction Socket
Horizontal Soft Tissue Thickness
Gap Distance and Wound Healing
Bone Thickness and Ridge Dimensional Change
Peri-implant Soft Tissue Thickness
Dual-Zone Socket Management
Sulcular Bleeding at First Disconnection of an Implant Healing Abutment
Cement- Versus Screw-Retained Provisional and Definitive Restorations
Abutment Selection: Materials and Color Considerations
Management of Teeth with Periapical Lesions, Fistulae, and Ankylosis
Implant Design for Immediate Placement
Critical Points to Remember
References
Chapter 3: Management of Type 2 Extraction Sockets
Implants Placed Immediately into Type 2 Extraction Sockets
Delayed Implant Placement
Flap Design for Delayed Implant Placement After Ridge Healing
References
Chapter 4: Management of Type 3 Extraction Sockets
Treatment of 3 mm of Midfacial Recession
Treatment of 1 mm of Midfacial Recession with Absence of Labial Bone Plate
Conclusion
References
Chapter 5: Clinical Management of Posterior Teeth
Tooth Extraction for Multirooted Teeth
Implant Placement into Molar Extraction Sockets
Alternative Immediate Molar Implant Placement Strategies
Clinical Example
Delayed Protocol for Molar Teeth
Conclusion
References
Chapter 6: Important Considerations in Implant Dentistry
Cementation Methods
Impression-Making Techniques
Complications
References
Chapter 7: Clinical Case Appendix
TYPE 1
Case 1
Case 2
Case 3
Case 4
Case 5
Case 6
TYPE 2
Case 7
Case 8
TYPE 3
Case 9
MOLARS
Case 10
Case 11
Index

Citation preview

Tarnow Chu

The

3  Management of Type 2 Extraction Sockets 4  Management of Type 3 Extraction Sockets 5  Clinical Management of Posterior Teeth 6  Important Considerations in Implant Dentistry 7  Clinical Case Appendix

Single-Tooth Implant

2  Management of Type 1 Extraction Sockets

The

1 History and Rationale for Anterior and Posterior Single-Tooth Implants

A Minimally Invasive Approach for Anterior and Posterior Extraction Sockets

Contents

Single-Tooth Implant

Dennis P. Tarnow, dds Stephen J. Chu, dmd, msd, cdt

A Minimally Invasive Approach for Anterior and Posterior Extraction Sockets

ISBN 978-0-86715-771-0

90000>

9 780867 157710

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The Single-Tooth Implant A Minimally Invasive Approach for Anterior and Posterior Extraction Sockets

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The

Single-Tooth Implant A Minimally Invasive Approach for Anterior and Posterior Extraction Sockets

Dennis P. Tarnow, dds Clinical Professor and Director of Implant Education Department of Periodontology Columbia University College of Dental Medicine Private Practice New York, New York

Stephen J. Chu, dmd, msd, cdt Adjunct Clinical Professor Ashman Department of Periodontology & Implant Dentistry Department of Prosthodontics New York University College of Dentistry Private Practice New York, New York

Berlin, Barcelona, Chicago, Istanbul, London, Mexico City, Milan, Moscow, Paris, Prague, São Paulo, Seoul, Tokyo, Warsaw

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Library of Congress Control Number:2019943782

97%

©2020 Quintessence Publishing Co, Inc Quintessence Publishing Co Inc 411 N Raddant Rd Batavia, IL 60510 www.quintpub.com 5 4 3 2 1 All rights reserved. This book or any part thereof may not be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher. Editor: Leah Huffman Design: Sue Zubek Production: Angelina Schmelter Printed in China

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Contents Foreword  viii Preface  ix

CHAPTER 1  History and Rationale for Anterior and

Posterior Single-Tooth Implants  1 Immediate Versus Delayed Tooth Replacement Therapy Clinical Example Challenges with Immediate Implant Placement Classification of Extraction Sockets Diagnostic Aids for Socket Management: Radiographic and Clinical Examination CBCT Probes

CHAPTER 2  Management of Type 1 Extraction Sockets  19 Flapped Versus Flapless Tooth Extraction: Evidence-Based Rationale Blood supply to the labial plate Labial contour and ridge dimensional change Tooth Extraction Techniques with Specific Instrumentation Single-rooted anterior teeth Multirooted posterior teeth 3D Spatial Implant Placement Within the Anterior Extraction Socket The influence of implant position on restorative emergence profile Implant placement Implant angulation Implant depth Horizontal Soft Tissue Thickness Connective tissue grafts around implants and edentulous ridges Periodontal phenotype Gap Distance and Wound Healing Primary flap closure versus secondary-intention wound healing Case example and histologic evidence Hard tissue grafting of the gap

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Bone Thickness and Ridge Dimensional Change Peri-implant Soft Tissue Thickness Tissue discoloration around implants Layperson’s perception threshold of faciopalatal ridge collapse Dual-Zone Socket Management Bone graft materials Bone graft material for dual-zone therapy Prosthetic socket sealing iShell technique Sulcular Bleeding at First Disconnection of an Implant Healing Abutment Cement- Versus Screw-Retained Provisional and Definitive Restorations Abutment Selection: Materials and Color Considerations Management of Teeth with Periapical Lesions, Fistulae, and Ankylosis Periapical lesions and fistulae Ankylosed teeth Implant Design for Immediate Placement Tapered vs cylindrical implants, thread design, and thread pitch Platform switching One abutment, one time Coaxial versus straight implants Inverted body-shift design implant Wide-body versus regular-width implants

CHAPTER 3  Management of Type 2 Extraction Sockets  77 Implants Placed Immediately into Type 2 Extraction Sockets Clinical example Delayed Implant Placement Membranes for socket preservation Ice cream cone technique Delayed implant placement with immediate provisional restoration Flap Design for Delayed Implant Placement After Ridge Healing Punch technique Flap technique Soft tissue sculpting with the provisional restoration

CHAPTER 4  Management of Type 3 Extraction Sockets  101 Treatment of 3 mm of Midfacial Recession Treatment of 1 mm of Midfacial Recession with Absence of Labial Bone Plate

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CHAPTER 5  Clinical Management of Posterior Teeth  117 Tooth Extraction for Multirooted Teeth Implant Placement into Molar Extraction Sockets Type A Type B Type C Alternative Immediate Molar Implant Placement Strategies Clinical Example Delayed Protocol for Molar Teeth

CHAPTER 6  Important Considerations in Implant

Dentistry 

131

Cementation Methods Impression-Making Techniques Complications Occlusal overloading Breakage or delamination of the provisional restoration from temporary cylinders

CHAPTER 7  Clinical Case Appendix  141 Type 1 Case 1: Horizontal fracture of maxillary central incisor Case 2: Large internal resorption lesion Case 3: Internal resorption lesion at maxillary central incisor Case 4: Vertical crown fracture of maxillary central incisor Case 5: High smile line Case 6: High smile line and chronic fistula Type 2 Case 7: Loss of labial plate Case 8: Periapical lesion and tooth fracture with necrosis Type 3 Case 9: Loss of labial plate at maxillary central incisor Molars Case 10: External resorption lesion of maxillary first molar Case 11: Vertical root fracture of mandibular first molar Index  227

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Foreword

viii

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Education is the key to changing lives. It is fundamental to how practitioners treatment plan with the understanding of biology and eventually improve patient outcomes. Over the past three decades, I have had the opportunity and pleasure to work closely with Drs Dennis P. Tarnow and Stephen J. Chu in the arena of both domestic and international continuing dental education. Dennis and Steve are exceptional academic educators, prolific researchers, and caring private practitioners. Both are inspirational teachers and lifelong learners, always questioning and exploring the frontiers of dental knowledge with fresh insights and innovative approaches to everyday clinical dentistry. Exceptional teachers are hard to find, but these individuals are always rising to the challenge of turning on the lights in our darkness. Both are aware that only biologic principles dictate final clinical outcomes. Through their knowledge and expertise, they guide each of us in our search for the elusive truths in implant dentistry. Based on their clinical experiences and research findings, this textbook is comprehensive and engaging. Written by clinicians for clinicians, the flow and language are clear and to the point. The chapters progressively address diagnosis as well as simple to more complex

single-tooth implant scenarios. The book begins with a discussion of the history and rationale for anterior and posterior single-tooth implants, and then it walks the reader through the three types of sockets—type 1, type 2, and type 3— and their various indications and limitations. An entire chapter is devoted to clinical management of posterior teeth, followed by a chapter on cementation and impression-making techniques and complications. The final chapter is a clinical case appendix detailing 11 cases of single-tooth replacement in all types of sockets previously described. What a treasure trove! This fresh and insightful publication by two world-class masters in clinical dentistry who have worked together for decades will inspire the reader to keep learning and growing in the ever-changing world of dental knowledge. Learn from the best, increase your clinical predictability, enhance your problem-solving capabilities, and watch your practice grow with new knowledge and confidence. Let the lantern of learning keep shining.

H. Kendall Beacham, mba Assistant Dean, Linhart Continuing Education Program New York University College of Dentistry

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Preface periodontal and restorative interrelationships in treatment with great success alongside new and innovative techniques that enhanced esthetic outcomes in less treatment time for our patients. During the compilation of this book, the reader was always foremost in our minds, with the hope of providing not only a better understanding of diagnosis and treatment with evidence-based concepts but also biologic principles of wound healing, thus making patient care faster, easier, simpler, more predictable, and, in many cases, less costly. We hope you enjoy seeing the results of our professional journey in this challenging field and enjoy reading this textbook as much as we enjoyed composing it. We wish you much success in the treatment endeavors with your patients!

ix 

Our love and passion for dentistry as well as a desire to share what we have learned over the years as clinicians, teachers, and researchers led us to write this modern-day textbook on the single-tooth implant. The replacement of the single tooth with a dental implant is one of the most common clinical situations practitioners face on a daily basis. During our respective careers and close collaboration over the last 15 years, we have completely modified our approach to the management of hopeless teeth, especially in the esthetic zone. In the past, sockets were left untouched after tooth extraction for months before attending to the residual ridge. Today we perform “one surgery, one time” whenever possible, which is quite often and a huge benefit to both the patient and clinician alike. We have documented the

With contributions from Guido O. Sarnachiaro, dds

Richard B. Smith, dds

Clinical Assistant Professor Department of Prosthodontics New York University College of Dentistry

Private Practice New York, New York

Private Practice New York, New York

Acknowledgment Special thanks to Adam J. Mieleszko, cdt, for all the laboratory work presented throughout this book.

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IN THIS CHAPTER: • Immediate Versus Delayed Tooth Replacement Therapy • Clinical Example • Challenges with Immediate Implant Placement • Classification of Extraction Sockets • Diagnostic Aids for Socket Management: Radiographic and Clinical Examination

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Chapter 1

History and Rationale for Anterior and Posterior Single-Tooth Implants

1

T

he single-tooth implant restoration comprises roughly one-half of all the implant case types that present daily in a clinical practice, and in the authors’ experience, many are in the esthetic zone. This section discusses some of the current concepts, science, and knowledge associated with immediate implant placement and provisional restoration in anterior postextraction sockets, better known as immediate tooth replacement therapy because both the root of the tooth and the clinical crown are being replaced simultaneously. Some common questions that arise when a tooth is removed and an implant is placed into a fresh extraction socket include the following: • What happens when a tooth is extracted? • What kind of hard and soft tissue dimensional changes take place as a result? • Are there differences in wound healing of anterior versus posterior extraction sockets? • Should flap elevation be employed to remove the root remnant? • Should primary flap closure be used, or should the socket be allowed to heal by secondary wound intention? • What graft, if any, should be used?

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• Should a connective tissue graft be placed in conjunction with the implant? • What is the proper 3D spatial position of the implant within the extraction socket? • Does the graft alter the wound healing process of the extraction socket? • Does it make a difference if there is a residual gap after implant placement? • Should a provisional restoration or custom healing abutment be fabricated in conjunction with the implant, or is it better just to place a stock healing abutment? Which would be better in regard to implant survival, osseointegration, and esthetic success? These are just some of the questions that arise when immediate placement of implants into postextraction sockets is discussed. All of these topics remain controversial, and every practitioner has his or her own solutions, but how reliable are the results? This book seeks to answer these questions and to provide objective and concrete information to help clinicians, both specialists and general practitioners alike, place single-tooth implants and restore them with consistent periodontal, restorative, and esthetic outcomes in various clinical situations.

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Immediate Versus Delayed Tooth Replacement Therapy

Chapter 1: History and Rationale for Anterior and Posterior Single-Tooth Implants

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The survival rates for immediate implant placement are equal to, if not slightly higher than, those for delayed implant placement.1 The literature seems to support this.2–9 While the delayed protocol has survival rates higher than 90%, the immediate protocol boasts survival rates of 95%.5 Among anterior teeth alone, the survival rate increases to 97%.4,5 So it stands to reason: If the placement of an implant directly into the extraction socket has no bearing on that socket’s ability to heal, why not do it? After all, the socket is genetically engineered to heal whether or not a sterile titanium screw, which is biologically acceptable and compatible, is placed. The main advantage of immediate tooth replacement therapy is that it condenses treatment procedures into fewer patient appointments, thereby reducing overall treatment time and increasing patient comfort while preserving the natural shape of the surrounding hard and soft tissues (Table 1). Most of the procedures such as tooth extraction, implant placement, socket grafting, and provisional restoration are delivered at the first treatment appointment, so more time should be appropriately allotted. With this approach, the clinician has the ability and opportunity to preserve hard and soft tissues at the time of tooth extraction, especially for a single tooth and maybe even multiple adjacent implants. This preservation concept is critical for esthetics, which is a major advantage with today’s esthetically demanding and knowledgeable patients.10

Conversely, delayed implant placement affords the clinician the opportunity to perform all site development prior to implant placement, provided that the clinical situation is amenable to augmentation and correction.11–13 However, this protocol requires more treatment time: First the tooth is extracted, then the socket must heal for several months before implant placement with contour grafting is performed either as a single- or two-stage procedure. Once the implant has integrated, the implant is surgically exposed (two-stage procedure), and a flat profile healing abutment can be placed. The patient must return for nonsurgical soft tissue sculpting after soft tissue healing around the healing abutment, which is subsequently followed by another appointment for final impression making and definitive restoration14 (Table 2). This prolonged course of treatment is not ideal for the patient or the clinician, especially if all of the anatomy is present prior to tooth extraction.15 In addition, once the proximal contacts are eliminated following tooth removal, both interdental papillae shrink, and they are not always easily retrieved, especially in a thin scalloped phenotype. In 1997, Jemt showed that 1.5 years after implant placement, the mesial papilla filled completely only 68% of the time in 25 single-tooth implant sites (21 anterior sites), while the distal papilla had complete fill less than half the time (48%).16 Furthermore, papillae may not re-form to their pretreatment height of roughly 40% of the tooth length from the gingival zenith position. Immediate tooth replacement therapy provides a better opportunity for this re-formation.17,18 While the delayed approach allows for soft tissue maturation and site development,

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TABLE 1  Immediate implant protocol Appointment # 1

Surgical intervention

Healing time (weeks)

Tooth extraction, implant placement, socket grafting, provisional restoration or custom healing abutment

12–24



2

Impression making

None required



3

Delivery of definitive restoration

None required

TABLE 2  Delayed implant protocol Appointment #

Surgical intervention

Healing time (weeks)

1

Tooth extraction

6–12



2

Ridge augmentation*

12–24



3

Early implant placement*

12–24



4

Stage 2 uncovering

2–4



5

Nonsurgical soft tissue sculpting

2–4



6

Impression making

None required



7

Delivery of definitive restoration

None required

*Note that procedures #2 and #3 can be combined in some instances.

immediate tooth replacement therapy offers the distinct advantage that the existing tooth extraction site and socket become the osteotomy to help guide the placement of the implant. In a fresh extraction socket, the mucosal tissue is exposed from the trauma, so the provisional restoration or custom healing abutment should be well adapted to the contours of the extraction socket walls, maintain the peri-implant tissue in the preextraction state, and be cleaned or disinfected (ie, steam cleaning) prior to insertion

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regardless of the material used. The beauty of immediate provisional restoration is that the soft tissue architecture can be captured and preserved immediately at the time of tooth removal. The goal of therapy is to preserve, maintain, and protect the existing tissues rather than try to recreate what is lost. Proper 3D implant placement, platform switching, and correct soft tissue support with a provisional restoration can result in a predictable restorative and esthetic outcome.

3 Immediate Versus Delayed Tooth Replacement Therapy



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Clinical Example

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1

3

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A 21-year-old woman with a high smile line presented with advanced external resorption of the maxillary right central incisor at the mesiofacial aspect (Figs 1 to 3). The periapical radiograph showed a cavernous lesion that undermined the structural integrity of the tooth (Fig 4). The soft tissue margin of the right central incisor was slightly more coronal than that of the left central incisor, which is a benefit in treatment if recession should occur (see Fig 2). During tooth extraction, the weak coronal tooth structure fractured with the slightest force (Fig 5). The ingrowth of granulomatous tissue is seen within the mesiofacial socket wall (Fig 6). Sharp dissection with a no. 15c scalpel blade was used to remove the affected tissue, and a fine tapered surgical diamond bur (Brasseler #859 long shank) was used to section the root faciopalatally (Fig 7). The residual roots were luxated and removed without damaging the extraction socket (Fig 8; see chapter 2 for tooth extraction techniques). The socket was thoroughly debrided (Fig 9), and a 5.0-mm-diameter implant (Zimmer Biomet) was placed to the palatal aspect of the socket to allow platform switching (Fig 10). A preformed gingival shell former (iShell, BioHorizons/Vulcan Custom Dental) was used to capture the preextraction state of the

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5 Clinical Example

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15

peri-implant tissues (Figs 11 and 12). The shell was joined to a screw-retained PEEK (polyetheretherketone) temporary cylinder with acrylic resin (Super-T, American Consolidated) with the accompanying clinical crown (Fig 13). After autocuring of the acrylic resin, it was removed intraorally, contoured, and custom colored (OPTIGLAZE Color, GC America) (Figs 14 and 15) to match the contralateral central incisor. Note how the preformed gingival shell former captures the shape of the subgingival contours of the extraction socket without voids (see Fig 14), which would normally occur due to the formation of a clot as well peri-implant soft tissue collapse. The provisional crown restoration was tried back onto the implant to verify the shade, contour, and nonocclusal contact in maximum intercuspal position (MIP) and lateral excursive movements (Fig 16). The provisional crown was subsequently removed, and a flat-profile healing abutment with platform switching was placed to allow a small-particle, mineralized cancellous allograft to be packed into the labial gap (Fig 17). The healing abutment was then removed, and the provisional crown was reseated to contain and protect the graft material during the healing phase of therapy (Figs 18 and 19). After 1 week of uneventful healing, the patient

13

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16

17

7

20

returned to the office and showed resolution of the marginal gingival inflammation (Fig 20). At this point, the patient embarked on an exchange student program in Europe and did not return for final impression making until 13 months postsurgery (Fig 21). The tissue was stippled and healthy, and it was clear that the disease had fully resolved upon first removal of the provisional restoration prior to impression making (Fig 22). Pattern Resin (GC America) was used to capture the soft tissue profile so

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19

Clinical Example

18

21

22

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24

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that an accurate cast could be created (Figs 23 and 24). A metal-ceramic screw-retained definitive restoration was made in the dental laboratory (Figs 25 and 26). Attention was paid to the midfacial subgingival contour of the restoration to support the soft tissues at the proper gingival level to match the contralateral central incisor (Fig 27). Soft tissue blanching can be seen upon final crown insertion (Fig 28).

26

The technique of nonsurgical tissue sculpting is an effective treatment strategy in soft tissue contouring. The implant restoration is well integrated and in harmony with the surrounding teeth, tissues, and esthetics at 3 years posttreatment (Figs 29 to 31). The postoperative periapical radiograph shows radiographic bone stability 3 years after treatment (Fig 32).

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27

28

9 Clinical Example

29

31

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30

32

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Challenges with Immediate Implant Placement One of the biggest challenges that arises when most surgeons extract a tooth and place an implant into an extraction socket is what to do with the residual gap between the facial surface of the implant and the palatal aspect of the labial bone plate. Should a bone graft be placed? Is a bone graft necessary to achieve better survival rates of the implant in the esthetic zone? Will a bone graft improve osseointegration or boneto-implant contact around the implant? Will a bone graft change the cell type that occupies the implant surface? Will a bone graft prevent ridge collapse, thereby enhancing esthetics and preventing tissue discoloration?

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33

Several studies have reported high survival rates without bone grafting, which seems to support the conclusion that a bone graft is not critical for implant success.2–9 Probably the most common side effect of placing an implant into a fresh extraction socket is collapse of the facial ridge with midfacial recession. This occurs due to multiple factors: (1) the implant was placed or angulated excessively forward within the socket, leaving a paper-thin wall of bone, or (2) part of the buccal plate bone crest was missing during implant placement. Any of these clinical situations holds the potential risk for recession with immediate implant placement.19,20 Even though the implant will integrate, the case will be a failure cosmetically due to loss of the labial bone plate (Figs 33 to 35).

34

Fig 33 Dentofacial smile view of a patient who had received an immediate implant to replace the maxillary right lateral incisor at a previous dental office. Note the tissue discoloration associated with the implant and restoration. The dark color from the underlying titanium is distracting and unattractive. Fig 34 Intraoral view of the maxillary lateral incisor clearly showing the extent and magnitude of the discolored implant restoration, which extends beyond the free gingival margin. Fig 35 Following full-flap elevation to repair the site with a subepithelial connective tissue graft, note the lack of bone covering roughly half of the labial surface of the implant that leads to the dark discoloration of the tissues. 35

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36

Fig 36 Intraoral view of an implant placed excessively facial and distal in close proximity to the adjacent canine tooth. Note the loss in height of the mesiofacial papilla of the canine, while the mesiopalatal aspect of the papilla is still present. It can be this subtle if placement is not ideal in the esthetic zone.

37

Fig 37 Periapical radiograph of the lateral incisor shown in Fig 36 revealing the close toothimplant proximity to the mesial aspect of the canine and the accompanying crestal bone loss.

11 Challenges with Immediate Implant Placement

A second risk, and by no means less significant, is the potential loss of the interdental papilla following immediate (or delayed) implant placement (Fig 36). Several authors have suggested that a minimum distance of 1.5 mm be maintained between the implant and any adjacent tooth to maintain the crestal bone between the tooth and implant.21,22 The horizontal formation of biologic width and crestal pressure necrosis may be contributing factors in interdental crestal bone loss and recession if the implant-tooth distance is inadequate23 (Fig 37). Even though Khayat et al showed no evidence of pressure necrosis (resorption) of crestal bone with extremely high insertion torque of up to 178 Ncm, they did not measure the bone thickness surrounding the implants postinsertion.24 Subsequently, Barone et al correlated crestal bone loss with osseous thickness, concluding that there is a greater risk of hard tissue loss with high insertion torque (pressure) when the contiguous bone dimension is less than 1.0 mm.25 The clinical reality is that implants “drift” and migrate within the extraction socket to the side of least resistance both labially and interdentally (ie, the gap) during final placement to achieve the highest insertion torque value for primary stability. With the tapered coronal portion, the implant head is frequently placed subcrestally and in contact with the palatal bone during insertion. As the implant is torqued into place, the implant “bounces” off the palatal bone wall and migrates to the facial aspect of the socket (Fig 38). The use of a dynamic or static guide may be helpful to keep the osteotomy clean and the implant position on target for the intended placement. It is important to understand that not all extraction sockets are the same, and not all are suitable for immediate tooth replacement therapy. See chapter 2 for more information on the bone gap as well as chapters 3 and 4 on type 2 and type 3 sockets, respectively.

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B

Fig 38 Illustration of the preferred palatal position of an implant within an extraction socket (A), toward the cingulum of the tooth, for screw retention of the restoration. However, the implant can bounce off the palatal wall and migrate not only labially but also slightly distally (B). The use of a static guide may be helpful to keep the implant on track and in the correct final position.

A

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Classification of Extraction Sockets There are three different types of sockets (Figs 39 to 41) following tooth removal, and all have the prospective risk of midfacial recession.26 Type 1 sockets are the most ideal clinical situation because all the bone and soft tissues are present (see Fig 39). Type 2 sockets are less ideal because they present with a dentoalveolar dehiscence defect of the labial plate of bone that increases the risk of midfacial recession (see Fig 40 and chapter 3). Type 3 sockets present with an existing midfacial recession deficiency indicative of loss of both hard and

soft tissues (see Fig 41 and chapter 4). Type 1 sockets are more predictable to treat than the other classification types; however, there are specific treatment protocols and indications that allow these other types to be treated under the right conditions. Type 2 sockets are clinically deceiving because the soft tissue is available and appears the same as Type 1 sockets prior to tooth removal, but this soft tissue is only supported by the tooth root and not the underlying bone, which is absent. If the buccal plate is partially missing, there is risk of gingival recession when the tooth is extracted and an implant is placed. This is where most clinicians can get into trouble.

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TYPE 1

TYPE 2 13

40

Fig 39 Illustration of a type 1 extraction socket, defined as the labial bone plate and associated soft tissues being intact and present prior to tooth extraction.

Classification of Extraction Sockets

39

Fig 40 Illustration of a type 2 extraction socket, defined as the soft tissues being intact and present but the labial bone plate possessing a dentoalveolar dehiscence defect prior to tooth extraction. Fig 41 Illustration of a type 3 extraction socket where there is an existing midfacial recession deficiency indicative of loss of both hard and soft tissues prior to tooth extraction.

TYPE 3

41

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Diagnostic Aids for Socket Management: Radiographic and Clinical Examination CBCT With the advent of improved technology, specifically CBCT, clinicians now have the ability to

evaluate a potential extraction site in 3D space prior to treatment and make assessments about potential obstacles they may encounter during treatment. This has become the standard of care in most cases prior to implant placement. Several enhanced CBCT systems allow sectional scans to be performed to limit the amount of radiation exposure during this diagnostic phase. A sextant and even a single tooth can be imaged to assess the preoperative condition (Figs 42 to 45).

Fig 42 CBCT image of a patient with a Class II, division 2 malocclusion and a labial bone fenestration seen midroot on this radiograph. Fig 43 CBCT image of a patient with a fractured clinical crown visible on the palatal aspect at the junction between the tooth root and crown restoration.

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42

43

Fig 44 CBCT image of a patient with an internal resorption lesion and an apical root fenestration. Fig 45 CBCT image of a patient with a labial bone plate dehiscence defect or type 2 socket.

44

45

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Probes Another useful and practical diagnostic tool is the periodontal probe, which can be used for bone sounding to gauge the socket type based on the sulcus depth and osseous crest location. The use of a color-coded probe (Colorvue Biotype Probe, Hu-Friedy) can be especially helpful in appraising the periodontal phenotype of the patient before treatment (Fig 46). The white-tipped probe is used first. If it is visible under the facial aspect of the free sulcular gingiva, then the gingival phenotype is thin (Fig 47). If it is not visible, then the green-tipped probe is used to determine an intermediate phenotype (Fig 48) and the blue-tipped probe a thick phenotype (Fig 49).

THIN

47

INTERMEDIATE

15

THICK

46

49

Figs 46 to 49  Color-coded periodontal probes for appraising the periodontal phenotype of the patient.

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Diagnostic Aids for Socket Management: Radiographic and Clinical Examination

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References

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1. Cochran DL. A comparison of endosseous dental implant surfaces. J Periodontol 1999;70:1523–1539. 2. Wagenberg B, Froum SJ. A retrospective study of 1925 consecutively placed immediate implants from 1988 to 2004. Int J Oral Maxillofac Implants 2006;21: 71–80. 3. Wöhrle PS. Single-tooth replacement in the aesthetic zone with immediate provisionalization: Fourteen consecutive case reports. Pract Periodontics Aesthet Dent 1998;10:1107–1114. 4. Kan JY, Rungcharassaeng K, Lozada J. Immediate placement and provisionalization of maxillary anterior single implants: 1-year prospective study. Int J Oral Maxillofac Implants 2003;18:31–39. 5. De Rouck T, Collys K, Wyn I, Cosyn J. Instant provisionalization of immediate single-tooth implants is essential to optimize esthetic treatment outcome. Clin Oral Implants Res 2009;20:566–570. 6. Block MS, Mercante DE, Lirette D, Mohamed W, Ryser M, Castellon P. Prospective evaluation of immediate and delayed provisional single tooth restorations. J Oral Maxillofac Surg 2009;67:89–107. 7. Tortamano P, Camargo LO, Bello-Silva MS, Kanashiro LH. Immediate implant placement and restoration in the esthetic zone: A prospective study with 18 months of follow-up. Int J Oral Maxillofac Implants 2010;25:345–350. 8. Cooper LF, Raes F, Reside GJ, et al. Comparison of radiographic and clinical outcomes following immediate provisionalization of single-tooth dental implants placed in healed alveolar ridges and extraction sockets. Int J Oral Maxillofac Implants 2010;25: 1222–1232. 9. El-Chaar ES. Immediate placement and provisionalization of implant-supported, single-tooth restorations: A retrospective study. Int J Periodontics Restorative Dent 2011;31:409–419. 10. Cosyn J, Eghbali A, De Bruyn H, Collys K, Cleymaet R, De Rouck T. Immediate single tooth implants in the anterior maxilla: 3-year results of a case series on hard and soft tissue response and aesthetics. J Clin Periodontol 2011;38:746–753. 11. Buser D, Chen ST, Weber HP, Belser UC. Early implant placement following single-tooth extraction in the esthetic zone: Biologic rationale and surgical procedures. Int J Periodontics Restorative Dent 2008; 28:441–451. 12. Buser D, Bornstein MM, Weber HP, Grutter L, Schmid B, Belser UC. Early implant placement with simultaneous guided bone regeneration following single-tooth extraction in the esthetic zone: A cross-sectional, retrospective study in 45 subjects with a 2- to 4-year follow-up. J Periodontol 2008;79:1773–1781.

13. Chappuis V, Rahman L, Buser R, Janner S, Belser U, Buser D. Long-term effectiveness of contour augmentation with guided bone regeneration: 10-year results. J Dent Res 2018;97:266–274. 14. Zamzok J. Avoiding ridge laps through nonsurgical soft tissue sculpting on implant restorations. J Esthet Restorative Dent 1996;8:222–228. 15. Crespi R, Capparé P, Crespi G, Romanos GE, Gherlone E. Tissue remodeling in immediate versus delayed prosthetic restoration in fresh socket implants in the esthetic zone: Four-year follow-up. Int J Periodontics Restorative Dent 2018;38(suppl):S97–S103. 16. Jemt T. Regeneration of gingival papillae after single-implant treatment. Int J Periodontics Restorative Dent 1997;17:327–333. 17. Chu SJ, Tarnow DP, Tan JH, Stappert CF. Papilla proportions in the maxillary anterior dentition. Int J Periodontics Restorative Dent 2009;29:385–393. 18. Steigmann M, Cooke J, Wang HL. Use of the natural tooth for soft tissue development: A case series. Int J Periodontics Restorative Dent 2007;27:603–608. 19. Chen ST, Buser D. Clinical and esthetic outcomes of implants placed in postextraction sites. Int J Oral Maxillofac Implants 2009;24(suppl):186–217. 20. Merheb J, Vercruyssen M, Coucke W, Beckers L, Teughels W, Quirynen M. The fate of buccal bone around dental implants. A 12-month postloading follow-up study. Clin Oral Implants Res 2017;28:103–108. 21. Esposito M, Ekestubbe A, Grondahl K. Radiological evaluation of marginal bone loss at tooth sites facing single Branemark implants. Clin Oral Implants Res 1993;4:151–157. 22. Cosyn J, Sabzevar MM, De Bruyn H. Predictors of inter-proximal and midfacial recession following single implant treatment in the anterior maxilla: A multivariate analysis. J Clin Periodontol 2012;39: 895–903. 23. Rodriguez-Ciurana X, Vela-Nebot X, Segala-Torres M, Rodado-Alonso C, Cambra-Sanchez J, Tarnow DP. The effect of inter-implant distance on the height of the inter-implant bone crest when using platform-switched implants. Int J Periodontics Restorative Dent 2009;29:141–151. 24. Khayat PG, Arnal HM, Tourbah BI, Sennerby L. Clinical outcome of dental implants placed with high insertion torques (up to 176 Ncm). Clin Implant Dent Relat Res 2013;15:227–233. 25. Barone A, Alfonsi F, Derchi G, et al. The effect of insertion torque on the clinical outcome of single implants: A randomized clinical trial. Clin Implant Dent Relat Res 2016;18:588–600. 26. Elian N, Cho SC, Froum S, Smith RB, Tarnow DP. A simplified socket classification and repair technique. Pract Proced Aesthet Dent 2007;19:99–104.

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IN THIS CHAPTER: • Flapped Versus Flapless Tooth Extraction: Evidence-Based Rationale • Tooth Extraction Techniques with Specific Instrumentation • 3D Spatial Implant Placement Within the Anterior Extraction Socket • Horizontal Soft Tissue Thickness • Gap Distance and Wound Healing • Bone Thickness and Ridge Dimensional Change • Peri-implant Soft Tissue Thickness • Dual-Zone Socket Management • Sulcular Bleeding at First Disconnection of an Implant Healing Abutment • Cement- Versus Screw-Retained Provisional and Definitive Restorations • Abutment Selection: Materials and Color Considerations • Management of Teeth with Periapical Lesions, Fistulae, and Ankylosis • Implant Design for Immediate Placement

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Chapter 2

Management of Type 1 Extraction Sockets

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I

n the esthetic zone, implants can be routinely placed in type 1 sockets where the buccal plate and soft tissues are present. The results can be quite predictable and very favorable, especially when extraction is performed without flap elevation. This chapter addresses the most common questions, issues, and concerns with immediate tooth replacement therapy for single teeth.

Flapped Versus Flapless Tooth Extraction: Evidence-Based Rationale Tooth extraction can be performed with a flap or without flap elevation. While elevating a flap increases visibility and accessibility for the surgeon, it also results in more trauma to the surgical site. Traumatic extraction is problematic because it interrupts the blood supply to the extraction socket and results in buccolingual dimensional change of the ridge, which delays healing and compromises esthetics.1,2 In an animal model, Caneva et al showed that even with a split- or partial-thickness flap, the blood supply to the periosteum is compromised, leading to resorption of the labial bone plate.3

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Therefore, the flapless approach is best for immediate tooth replacement therapy because the anatomy and blood supply to the surrounding tissues is maintained and undisturbed.

Blood supply to the labial plate There are three sources of blood supply to the labial plate of bone: the periodontal ligament (PDL), the periosteum, and the endosseous blood supply from the bone marrow itself. The PDL is very vascular; it is rich in blood vessels. This vascularity is what allows our teeth to withstand the forces of occlusion and bone remodeling. But when the tooth is extracted, the PDL is eliminated. The buccal periosteum is therefore critical to the blood supply that is remaining and surrounding the socket. If a flap is elevated to remove a root tip, the blood supply to the buccal plate is temporarily severed and compromised. Even with perfectly positioned sutures performed elegantly, the blood supply will not reanastomose for 4 to 6 days, which means that the 30 seconds it takes to elevate the flap and remove the root tip consequently strangulates the socket of its main and remaining source of nutrition for almost a week. What remains in the socket is the endosteal blood supply, and because the labial wall is so thin, it is usually not present.

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Studies by Huynh-Ba et al and Braut et al showed that in 64% of anterior teeth evaluated, the buccal plates were only 0.5 mm thick. Another 23% were only 1.0 mm thick. So approximately 90% of the time, the labial bone plate in the maxillary anterior region is 1.0 mm or thinner.4,5 Cook et al showed the same trend: The labial bone plate was less than 1.0 mm in patients with thick gingival phenotypes and less than 0.5 mm in those with thin phenotypes.6 Of equal significance and importance is the work by Araújo et al in 2005 that showed that implants do not alter the wound healing of extraction sockets. If the labial bone plate is extremely thin (1.0 mm or less), the implant does not maintain the bone, and this bone will resorb, leading to loss of integration on the labial side.7 Consequently, Caneva et al showed that if the thin labial plate will resorb because it is avascular by nature, then implant position and diameter are key clinical strategies to allow integration and new labial plate formation to occur.8,9 Hence, smaller-diameter implants are used and placed toward the palatal side of the socket.10 Bone generally needs to be at least 1.5 to 2.0 mm in width in order to contain endosteum or marrow, which means there is little hope of the labial plate providing any blood supply to

the socket once the PDL and periosteum are severed.11–14 This can create a real potential esthetic dilemma for both the patient and clinician, namely midfacial ridge collapse and recession due to loss of the labial bone plate (Figs 1 and 2).

Labial contour and ridge dimensional change The literature includes several studies investigating dimensional changes to the ridge following extraction with flaps.15–20 In the studies by Lekovic et al, the investigators elevated flaps on anterior extraction sockets and then used primary closure to suture these flaps to the palate without any membranes or grafts.14,15 Six months later, they discovered a vertical change of only 1.0 mm because the palatal bone maintained the tissues intact and therefore the height of the ridge. However, there was a range of 4.4 to 5.9 mm in buccolingual dimensional change that resulted in recession, which is unacceptable esthetically. The literature also includes some studies investigating dimensional changes to the ridge following flapless tooth extraction.21–24 In these studies, Grunder, Vera et al, Brownfield and Weltman, and Degidi et al showed buccolingual dimensional changes of 1.0, 0.6, 0.8,

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Fig 3 Preoperative illustration of a tooth with a preexisting clinical crown fracture to be removed.

Fig 4 Use of a small no. 15c blade placed intrasulcularly to sever the supragingival fibers surrounding the tooth. Note that periosteal elevators are NOT used, which could tear these delicate tissues.

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Fig 6 Fractured clinical crown with the root tip still remaining in the socket.

and 1.3 mm, respectively. This is a significant difference compared to the 3.0 to 5.0 mm of ridge collapse seen with traumatic extraction and flap elevation. These numbers demonstrate that the buccolingual dimension of the ridge can be devastated in an attempt for easier access to the surgical site through flap elevation. Therefore, clinicians must rethink the way tooth removal is approached. After extraction, the socket is essentially a gaping hole; if a root tip remains, then smalltipped diamond burs, piezoelectric instruments, and PDL elevators should be used to create a purchase point to remove them. Unless the tooth is impacted, a flap should not be elevated. If the buccal plate is present, it should be left undisturbed. Maintaining this buccolingual dimension, even in posterior areas where collapse can lead to buccogingival food impaction, will facilitate more successful outcomes later in treatment.

Tooth Extraction Techniques with Specific Instrumentation

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Single-rooted anterior teeth The most challenging part of single-tooth replacement therapy in the esthetic zone is atraumatic tooth extraction because the labial bone plate is extremely thin and delicate and can be damaged during root removal. It is important that the clinician has the proper armamentarium for this procedure. It is critical that the supracrestal gingival fibers are severed through sharp dissection with a surgical scalpel prior to using fine beak pliers or forceps that can achieve a purchase onto the root surface. A rotation movement is recommended in lieu of buccolingual luxation, which can fracture the facial bone plate (Figs 3 to 10). Clinical crown fracture below the level of the free gingival margin (FGM) or osseous crest

Tooth Extraction Techniques with Specific Instrumentation

Fig 5 Use of extended-tip extraction forceps to remove the tooth by rotational movement with minimal buccolingual motion. This will help avoid fracturing the thin labial plate of bone.

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Fig 7 Crown part of the fractured tooth with the post and core restoration intact.

Chapter 2: Management of Type 1 Extraction Sockets

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Fig 8 Extended beak forceps are used to engage the remaining broken root tip. It is important to establish a purchase onto the remaining root structure in the sulcus to the osseous crest where the biologic width resides.

Fig 9 Removal of the root tip with rotation. Note that the extended-tip forceps need only a few millimeters of coronal tooth structure to grasp onto the tooth for root removal.

Fig 10 Removed residual root tip.

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Fig 11 Preoperative illustration of a tooth with a clinical crown fracture to be removed. This image represents a situation where the remaining root tip is fractured to the osseous crest with no coronal tooth structure to grasp.

Fig 12  Occlusal view of remaining broken root tip at the osseous bone crest.

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Fig 14  The tooth can be sectioned in a buccolingual direction, creating a “cat eye” shape, while respecting the thin labial bone plate to split the root into two parts. This will decrease the pressure on the thin buccal plate of bone when the two root pieces are wedged apart.

Fig 15 The root tip following hemisection in a buccolingual direction.

Fig 16 A PDL elevator is placed into the created space, and the roots are then split and luxated apart.

requires supplemental tools to remove root tips within the extraction socket. The strategy here is to create a purchase point between the socket wall and the root remnant at the expense of the residual root structure that is to be discarded. This point should be made at the palatalinterproximal aspect of the root/socket where

the bone is thicker and away from the thin labial plate and esthetic zone. Long-shank high-speed tapered diamond burs (Brasseler #859 surgical bur) are recommended to prepare the root. Once this space has been established, smalltipped PDL elevators can be inserted to luxate the residual root fragment (Figs 11 to 21).

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Tooth Extraction Techniques with Specific Instrumentation

Fig 13 Use of a small-diameter surgical bur (Brasseler #859) intrasulcularly to remove tooth structure and create room for a small PDL elevator to engage the root.

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Figs 17 and 18 The weaker root half is mobilized mesiodistally until it is removed.

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Fig 19 The remaining root tip can be luxated into the space where the first root was removed. This will minimize any pressure on the thin buccal plate of bone.

3D Spatial Implant Placement Within the Anterior Extraction Socket

Fig 21 Socket after removal of the fractured root. Notice that NO flaps were elevated, and the tissues are clean and intact.

Multirooted posterior teeth For information on multirooted posterior teeth, see chapter 5.

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Fig 20 Removed sectioned roots.

Unfortunately, there is little consensus on the ideal spatial position of a dental implant. However, Grunder et al14 recommended that there be at least 2.0 mm of bone facial to the surface of the implant, and Linkevicius et al25 recommended 2.0 to 3.0 mm of vertical tissue thickness or implant depth over the implant-abutment interface. These concepts are universal to immediate (postextraction socket) and delayed (healed or augmented ridge) implant sites as well as cement- and screw-retained restorations. Even though cement-retained restorations have recently fallen out of favor due to the potential risk of iatrogenic peri-implantitis (peri-cementitis) from residual cement and irretrievability of the

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Figs 22 and 23 Implant placed 3 to 4 mm from the midfacial FGM, equivalent to the buccal crest of bone.

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restoration, techniques have been developed to solve these issues.26 Therefore, the ideal implant position would be 3.0 to 4.0 mm in an apicocoronal position from the soft tissue crest, slightly palatal to a line bisecting the buccolingual position of the definitive restoration with a cingulum sagittal angulation, and bisecting the mesiodistal space with at least 1.5 mm between the implant and adjacent teeth27 (Figs 22 to 24).

The influence of implant position on restorative emergence profile In 2011, Du et al published an article on the emergence angle around maxillary anterior teeth.28 They looked at the relative cementoenamel junction (CEJ) and the interface between the clinical crown and root to aggregate the emergence angle relative to the long axis of the tooth. They reported an average emergence angle of about 15 degrees for the central incisor and anterior teeth in general (range, 11 to 15

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degrees). While this value is a starting point for shaping the emergence profile, it is not the only important parameter; the contour of the restoration is based on the spatial implant position, and it is essential to develop the proper emergence profile for hygiene and esthetics. It is common for the subgingival contour of the restoration to extend beyond 15 degrees around natural teeth because of the placement of the implant, especially with a palatal aspect bias of the socket in relation to implant depth, diameter, and platform switching. The clinical reality is that restorative contour is a direct function and outcome of implant positioning. The contour will depend on how much support the soft tissues will need; if the implant is placed more to the palatal aspect, these tissues will require more support and therefore contour, whereas if it is placed more to the facial aspect, less contour is required.29–31 Altering the subgingival shape and diameter of a natural tooth root or abutment-crown assembly of an implant restoration is a strategy that

3D Spatial Implant Placement Within the Anterior Extraction Socket

Fig 24 Implant placed slightly to the palatal aspect to allow the screw channel to exit at the cingulum area. This will prevent excess residual cement during provisional restoration and thereby promote healing.

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26 Chapter 2: Management of Type 1 Extraction Sockets

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28 3 MONTHS

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can be used to manipulate soft tissue height. Undercontour allows tissue on the buccal aspect to move coronally, while overcontour pushes the tissues apically.32 In Figs 25 to 29, for example, a diamond bur was used to alter the shape and decrease the diameter of the maxillary right central incisor at the subgingival level. The provisional restoration was then relined short of the FGM where the recontouring was done (Fig 30). Three months later, the soft tissue had migrated up to the level of the provisional restoration, resulting in a gain of about 1 mm of soft tissue height based on the change in clinical crown root morphology (Fig 31). This phenomenon occurs when the diameter of the tooth is decreased and thereby allows the soft tissue to migrate more incisally.

31

In the best of circumstances, the implant restoration at the cervical aspect should mimic the contours of the natural tooth (Figs 32 and 33).

Implant placement Implant placement too close to the labial aspect of the socket is a significant esthetic dilemma that often results in loss of bone and midfacial recession. In such circumstances, restorative undercontouring can be used to compensate for poor facial implant position if the implant is placed deep enough to correct for this poor angle of placement. However, in more extreme cases, implant removal, ridge augmentation, and implant replacement in the proper position are indicated as good treatment options (Figs 34 to 39).

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33 IMPLANT

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41

Implant angulation

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Originally published in: Chu SJ, Tarnow DP. Managing esthetic challenges with anterior implants. Part 1: Midfacial recession defects from etiology to resolution. Compendium 2013;34(special issue 7):26–31. Copyright © 2013 to AEGIS Publications, LLC. All rights reserved. Used with permission of the publishers.

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Restorative contour is also a function of implant angulation, which is not much different than positioning and can pose prosthetic challenges for screw-retained restorations with an incisal orientation. Poor implant angulation or placement to the facial aspect often results in poor contour of restorations, which then require overcontouring of the facial aspect of abutments and/or crown combinations. This overcontouring promotes soft tissue pressure and subsequently encourages midfacial recession (Figs 40 to 43).

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FACIAL RIDGE LAP

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FACIOGINGIVAL UNDERCUT

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48

Implant depth The vertical component of implant placement must also be considered in regard to restorative contour. With shallow implant depth, the restorative dentist frequently only has a singular option of creating a restoration with a facial ridge lap (Fig 44). However, with a deeper or more apical placement of the implant, there will be a more gradual subgingival contour, which requires vertical implant positioning to achieve

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49

the proper implant restorative emergence profile (Figs 45 to 49). If a palatally positioned implant is not placed deep enough, then more facial contour is required to support the soft tissue profile, and a faciogingival undercut will have to be created in the crown (see Fig 45). In a fresh extraction socket, it is known that placing the implant more to the palatal side will allow the blood clot to fill the gap, thereby facilitating bone apposition and consequently supporting

3D Spatial Implant Placement Within the Anterior Extraction Socket

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the formation of a new thicker buccal plate, but it is important to place the implant to greater depth in order to better control the midfacial contour of the restoration. It is recommended to place implants in extraction sockets at least 3.0 mm but no more than 4.0 mm from the midfacial FGM, suggestive of the average midfacial crest of bone; full midfacial contour may still be required to support the soft tissues (see Figs 48 and 49). From a prosthetic restorative standpoint, proper implant depth is crucial to obtain a more gradual contour. Similarly, greater implant depth is necessary for platform switching implant designs, where there exists a smaller-diameter implantabutment combination and prosthetic interface. In these instances, placing the implant 1.0 mm more apical can result in a more gradual implant restorative emergence profile. This little change in positioning can make a significant difference because contour is an important consideration from the standpoint of the restorative dentist, not to mention in regard to maintenance, hygiene, and gingival esthetics. Lastly, the implant restorative emergence profile for both cement- and screw-retained restorations should be the same (Figs 50 and 51).

50

Horizontal Soft Tissue Thickness The horizontal thickness of the peri-implant soft tissues is important when it comes to masking different-colored substrate materials as well as resisting midfacial gingival recession.33,34 For cement-retained restorations, some manufacturers have advocated placing an undercontoured or O-ring type of transmucosal abutment above the implant connection to potentially allow the soft tissues to migrate into that area, thereby thickening and enhancing these tissues. However, recent papers by Patil et al compared this abutment design with the straight abutment and essentially found that they were the same in terms of marginal bone loss, attached mucosa,

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Connective tissue grafts around implants and edentulous ridges The use of connective tissue grafts from the palate and tuberosity have been around since the 1980s. Initially they were used for ridge augmentation before guided bone regeneration was developed40 and around teeth for root coverage.41,42 As implants were becoming more popular and being used more frequently, it was a natural extension to use these autogenous grafts to not only help increase the zone of attached and keratinized gingiva around implants but also for ridge augmentation. The prime advantage of using these grafts is that the patient’s own tissue is being grafted and there is no immune response to the graft. The graft is also vital tissue and therefore does not always have to completely covered to be successful. This differs from dermis allografts from tissue banks, which must be covered to be effective. Other advantages include the lack of additional expenses to the clinician as well as the biocompatibility of the graft. The main disadvantage of using fresh connective tissue is that a donor site is required. This can lead to more postoperative discomfort during the

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healing phase and possibly increase the chance of bleeding. In addition, there are limitations to the amount of tissue available for harvesting. Each patient’s palate is different in thickness; it can be thin or thick, which will determine the amount of graft material available. Dermis allografts can also be used for augmentation procedures where only soft tissue is required. The obvious benefits to the use of these materials are that there are virtually an unlimited amount available and large areas can be treated simultaneously. There is also no need for an extra surgical site, and the postoperative discomfort is reduced compared with autogenous connective tissue grafting. Connective tissue grafts are also being used after extraction of teeth and immediate or delayed placement of implants. Presently, this is a topic of interest and attention, and every clinician has their own recipe that works best for them.

Periodontal phenotype The differences in hard and soft tissue characteristics between patient types have been well documented in the dental literature.43–45 Tooth morphology, specifically shape, has also been linked with different periodontium types; square teeth generally correlate with a thick flat gingival phenotype, while triangular tooth forms correlate with a thin scalloped phenotype. One of the most compelling studies defining labial bone plate thickness and dimension in different periodontal phenotypes with implant-related ramifications was published in 2011 by Cook et al.6 They found that patients with a thin phenotype on average possessed a bone plate thickness of about 0.6 mm, compared to 1.2 mm for patients with a thick phenotype. What is interesting to analyze here is that there is likely very little difference in actual labial bone plate thickness between the phenotypes, and the reported differentiation may lie in the thickness of the overlying soft tissues. Because the bone is quite thin in both phenotypes, the differentiating factor may be the thickness of the

31 Horizontal Soft Tissue Thickness

pink esthetic score, probing depth, and patient satisfaction.35–38 They concluded that using the curved undercontoured abutment versus the straight abutment made no tangible clinical difference. Conversely, a study conducted by Saito et al in 2018 comparing the effects of platform switching on peri-implant labial soft tissue thickness found that platform switching does enhance these tissues by about 1.0 mm (mean 1.38 mm) with an average platform shift of 0.33 to 0.58 mm.39 In addition, the amount of horizontal thickness achieved was greater than 2.0 mm, which is critical for color masking of metallic implant abutments/crowns. The essential question that remains is the correlation between peri-implant soft tissue gain and ridge dimensional change or collapse, which is presently unknown.

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peri-implant soft tissues. Hence, these authors advocate treating maxillary anterior sites as high-risk esthetic cases in all instances. However, the patient’s periodontal phenotype does inform the restorative contour to be made. While more contour is required to support thicker tissues, a thin phenotype warrants a more delicate straight or concave contour to avoid any type of midfacial recession defect associated with restorative contour.32

Gap Distance and Wound Healing When a tooth is extracted and an immediate implant is placed, there is often a facial bone gap—the distance between the labial surface of the implant and the palatal aspect of the extraction socket bony wall. The major question

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BONE GAP

then becomes: What kind of wound healing occurs against the implant surface? In Fig 52, the periodontal probe indicates a bone gap of about 4.25 mm around an extraction socket implant replacing a maxillary canine. This gap is greater than 1.5 mm, which is typically the threshold for failure of osseointegration. However, in this case, the bone healed very nicely simply by leaving the clot undisturbed. Flap elevation was not performed in the absence of primary closure or use of a membrane. How does this happen? Research dating back as far as 1988 shows compelling data regarding gap distance and wound healing, predominantly in simulated extraction sockets.46–50 In his classic work, Carlsson et al noted a fibrous seam between the implant and bone in every case in which there was a space greater than 1.5 mm.46 Gotfredsen et al, Knox et al, Stentz et al, and Akimoto et al showed the same results.47–50 Why would

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Primary flap closure versus secondary-intention wound healing In a typical extraction socket, the nearest source of epithelium to the blood clot is obviously at the wound edge. If this epithelium is left to remain in its original position and allowed to heal by secondary intention, the socket will fill with bone. It does not matter if an implant is placed in the middle of it or not; it will still heal and fill with bone. This occurs because the wound edge epithelium cannot traverse the blood clot because this clot is avascular (remember that epithelium does not have its own separate blood supply). Instead it must wait for the underlying granulation tissue from the socket walls underneath to form new blood vessels (angiogenesis) to carry it across the clot. These tissues cannot form any faster than the new blood vessels will allow. Therefore, bone will slowly form and reach the implant in the middle of the socket. Conversely, with primary flap closure, the epithelium and fibrous connective tissue can travel over the top of the socket and fill downward with granulation tissue before the new bone has a chance to fill the socket, hence the fibrous seam often seen with implants placed with flap elevation, suturing over the socket, and bone gaps larger than 1.5 mm. Unlike skin epithelium, which after suffering an abrasion goes under the blood clot and uses fresh connective tissue underneath the clot as the blood supply necessary for healing, the extraction socket epithelium of a similarly sized wound without primary flap closure cannot do the same because of the depth of the socket. Because the socket is so deep, epithelialization is much slower. While a skin abrasion 8 to 10 mm in diameter takes about 7 days to epithelialize and for the clot to exfoliate, the typical human extraction socket takes about 3 weeks. If no flap is used, the epithelium takes time to cover the socket. Because the young blood vessels from the new bone replace the clot before the epithelium can traverse the top

33 Gap Distance and Wound Healing

these results not hold up today? Well, let’s take a closer look at the Akimoto et al study to see why we may expect different outcomes with modern treatment concepts.50 In their study in a dog model, Akimoto et al extracted the teeth, allowed socket healing, and then placed implants in such a way that there was either no space or a 0.5-mm, 1.0-mm, or 1.4-mm gap around the implant head. These implants were secured into the bone apically after a trephine was used to widen the coronal portion around the implant, thereby creating a simulated extraction socket. The top section of each implant was left with a gap within these sockets. In the control group, where there was no gap distance, beautiful bone integration was achieved and seen histologically against the entire implant surface. However, when there was a 1.4-mm gap, a band of fibrous tissue resulted, which is in accord with the other studies previously mentioned. However, it is important to note that in this study and the others, flaps were elevated and closed over the top of the implants without a membrane. In addition, the residual bone dimension surrounding the implants was not measured in this study or any of the others mentioned. Work by Araújo et al in 2005 and Caneva et al in 2010 clearly showed the importance and significance of bone plate thickness in the wound healing process and its effect on resorption and remodeling.7–9 By bringing the flap over the top, because it is a pedicle and has blood supply, it will allow the fibrous tissue to grow down faster than the bone can fill in the gap, resulting in the fibrous seam and nonintegration of the implant. Had a membrane been placed, this fibrous seam could have been avoided. Other factors could have been implant depth, vertical soft tissue thickness as per Linkevicius’s research,25 as well as implant microsurface. However, more importantly, what would have happened if no flap had been elevated in the first place and the site allowed to heal through secondary-intention wound healing, which is what we would have advocated?

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53

1 WEEK

54

6 WEEKS

55

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34

of the socket, it stands to reason that gap size may not make any difference. The socket will eventually heal with bone formation through secondary-intention wound healing.51

Case example and histologic evidence In a serial extraction case, a maxillary left canine was removed, and a narrow-diameter implant was placed (4.0 mm) that left a very wide facial gap distance of 4.25 mm (see Fig 52). This is over twice the bone gap dimension previous research has shown to be associated with loss

Tarnow-Chu_CH02.indd 34

of integration. However, treatment continued with placement of a healing abutment. After 1 week, note the yellow-colored clot in the socket against the abutment, protecting the socket from food impaction during initial healing (Fig 53). At 6 weeks, there is granulation tissue (Fig 54). Normally this would show up at about 3 weeks, but because the socket was so wide and the distance so great, it took twice as long for the new blood vessels to form. The clot is still there protecting the surface from contamination. At 9 weeks, the socket is starting to epithelialize and keratinize (Fig 55). And at 12 weeks, it is nicely keratinized (Fig 56).

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57

5 MONTHS

59

35 Gap Distance and Wound Healing

58

At 5 months, it was time to load the implant and sculpt the soft tissue (Fig 57). After removal of the healing abutment, it was clear that tissue had formed to the top of the implant, but the question was what type of tissue was present. The implant was loaded, the soft tissue was sculpted, and the site was allowed to heal for another 3 to 4 months. Figure 58 shows the finished restoration. There was no pocket depth, and the tissue was healthy and stable. But it still remained to be seen what tissue cell type healed against the implant surface. A CBCT

Tarnow-Chu_CH02.indd 35

showed 3.1 mm of bone on the facial aspect of the implant (Fig 59), but the only way to know for sure was through histologic sectioning. The patient agreed with informed consent to donate his implant to science. The implant was removed with a very minimal block section, the bone was reconstructed, and another implant was placed after healing. There were adjacent implants on either side of this site, so a fixed dental prosthesis could be made if necessary, but the replaced implant healed uneventfully.

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61

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36

60

Figure 60 shows the histologic section of the implant. At the top where it meets the crown, there is slight artifact, probably from where bone sounding was performed prior to removal with only the clot covering the implant during healing. The epithelium had adhered to the top of the implant, even though it was totally exposed, showing wonderful tissue adaptation. At the shoulder of the implant, there was connective tissue (Fig 61). Most importantly, there was bone up against the first thread of

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62

the implant with normal biologic width above it; therefore, we have proof of principle that a large gap distance allowed to heal by secondary intention, even with a 4.2-mm facial gap, allows for osseointegration (Fig 62). This histologic case report confirms that gap distance is not critical as long as (1) the clot forms and is left undisturbed, (2) no flap is elevated over the top of the socket, and (3) the socket is allowed to heal by secondary intention.51

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the particles eventually are pushed aside and incorporated into the bone.52 From the standpoint of implant survival or osseointegration, it is not critical that this gap is grafted. Rather, esthetic concerns often mandate grafting the gap to maintain the shape of the ridge, prevent its collapse, as well as mitigate recession of the peri-implant soft tissues. The graft material is not relevant from the standpoint of what cell type heals against the implant surface, which is always based on the patient’s own wound healing potential.

Bone Thickness and Ridge Dimensional Change

Hard tissue grafting of the gap How does bone grafting affect these biologic processes of extraction socket healing? While it may preserve the ridge shape and help prevent tissue collapse and recession, the bone’s histologic response to wound healing is the same with or without a graft material or type. When a graft is placed into an extraction socket, the particles basically are in the way of the new granulation tissue emanating from the bone to seal the implant from the oral cavity. These particles essentially get pushed around, tumbled, and replaced by connective tissue, granulation tissue, and bone. Figure 63 shows how even after 2.5 years, the graft particles still remain and are surrounded by bone. However, they are not in contact with the implant; rather new bone and marrow forms against the implant surface. No matter how much force is used to pack the bone graft into the intrabony defect,

Tarnow-Chu_CH02.indd 37

The authors of this book recently conducted several studies on tissue thickness and buccolingual dimensional change in extraction sockets.53,54 The overall study involved four treatment groups, and test subjects were included from private practices in New York, Atlanta, and Buenos Aires, Argentina. The four groups were the following: 1. No graft was used, and no provisional restoration was placed (Fig 64).53 This is similar to what Ueli Grunder did in his control group of the study where he only placed an implant with a straight healing abutment.21 2. No graft was used, but a provisional restoration was placed to maintain the soft tissue shape (Fig 65). 3. A graft was used, but no provisional restoration was placed, just a healing abutment (Fig 66). 4. A graft was used, and a provisional restoration was placed similar to the case presented in chapter 1 (Fig 67).

Bone Thickness and Ridge Dimensional Change

63

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GROUP 1 NO GRAFT, NO PROVISIONAL

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65

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GROUP 2 NO GRAFT, BUT A PROVISIONAL

In group 1, with no grafting or provisional restoration, the buccolingual dimensional change at 3.0 mm apical to the FGM was 1.1 mm. This data is in line with that found by Grunder, which implies that this is the dimensional change that we can expect when teeth are extracted without flap elevation. In group 2, with no grafting but with a provisional restoration, the numbers are better at 0.4 to 0.5 mm. So supporting the tissue with a provisional restoration at the time of immediate implant placement provides an extra 0.5 mm in average thickness of the ridge.

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GROUP 3 GRAFT, BUT NO PROVISIONAL

67

GROUP 4 GRAFT AND PROVISIONAL

39 Bone Thickness and Ridge Dimensional Change

66

In group 3, with grafting but no provisional restoration and just a healing abutment, the results were surprising and even better; the graft alone helped to maintain ridge shape and contour. In group 4, with grafting and immediate provisional restoration, there was essentially no ridge dimensional change (0.1 mm); what a paradigm shift. With this data, now there is clinical evidence defining predictable results for ridge changes following tooth extraction, immediate implant placement, bone grafting, and immediate provisional restoration (Fig 68).

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Change in faciopalatal dimension (mm)

0.2 0.0 –0.2 –0.4 –0.6 –0.8 –1.0 –1.2 68 –1.4

Distance from FGM (mm)

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0

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BG, bone graft; PR, provisional restoration.

Peri-implant Soft Tissue Thickness Buccolingual gingival thickness is important for the masking ability of different substrate materials and abutment colors. A minimum of 2.0 mm is required to mask the color of the underlying abutment and perhaps the implant as well.33 In the same study investigating buccolingual dimensional changes, the authors also evaluated soft tissue thickness.54 The dimension of the free gingiva was measured at three different sites and levels—the gingival third, which was approximately 3.0 mm from the FGM adjacent to the implant-abutment interface; the middle third, which is about 2.0 mm from the FGM; and the incisal third, which is about 1.0 mm from the FGM (Fig 69). The incisal third is always thin because it converges to an apex, but the middle and gingival thirds should be sufficiently thick to mask the darkness of the underlying metal implant-abutment assembly. In group 1, with just the healing abutment and no graft, the incisal third was very thin: 1.2 mm. The middle and gingival thirds were 1.8 and 2.3 mm, respectively. When a provisional restoration was placed without grafting (group 2), the incisal third was similar, but the middle and

69

gingival thirds increased in thickness. Use of a graft without a provisional restoration (group 3) and only a stock healing abutment had almost identical results to group 2. However, when both grafting and a provisional restoration were used, the middle third thickness increased to 2.4 mm, and the gingival third thickness increased to 3.1 mm. Here the soft tissue has been thickened beyond the 2.0 mm threshold for masking the underlying abutment color. Once again, the best combination is grafting with a provisional restoration to anatomically contain the graft material, which ultimately thickens the peri-implant soft tissues (Fig 70).

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Tissue discoloration is a real issue that leads to unesthetic outcomes in implant therapy. Several studies have been performed on the threshold of color perception for both clinical crown (white) and gingival (pink) colors.55–57 Over a decade ago, Park et al noticed this phenomenon with tissue-level implants with a trumpet-shaped neck, reporting an incidence of pink color change approaching 100%.55 More recently, Benic et al retrospectively reported a 60% gingival discoloration rate associated with single-tooth implants.57 The previous studies on bone grafting the gap with a provisional restoration (dual-zone therapy) showed that ridge collapse could be limited to less than 0.2 mm and peri-implant tissue could be enhanced by 1.0 mm without connective tissue grafting. In this patient population, it was noted that tissue discoloration decreased from 100% and 60%, respectively, to 20%, with a pink perception threshold of 3.1.58

Tarnow-Chu_CH02.indd 41

Layperson’s perception threshold of faciopalatal ridge collapse How much ridge collapse is visibly noticeable? Because tissue discoloration is linked to hard and soft tissue collapse, it is important that the hard and soft tissues be supported to prevent this adverse outcome. According to Johnston and Kao as well as Ghinea et al, the threshold of color difference acceptability is 3.7.59,60 Sailer et al recently established a threshold of 3.1 for pink color perceptibility.61 In an unpublished web-based study by Chu and da Silva et al, the soft tissue color difference between two central incisors in cases with various amounts of soft tissue collapse (0.25 to 1.5 mm) was investigated. The ∆E, or color difference, between the right and left central incisor in regard to pink gingival color, not tooth color, was measured with a spectrophotometer. In cases with less than 0.25 mm of collapse, the ∆E between the gingival color of these central incisors was less than 3.1; however, with 1.0 mm or more of collapse, these ∆E numbers were greater than 3.1, indicating a potential esthetic problem.

Peri-implant Soft Tissue Thickness

Tissue discoloration around implants

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71

DUAL-ZONE SOCKET MANAGEMENT

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42

Tarnow-Chu_CH02.indd 42

Based on these values, 100 laypeople were surveyed and asked, “Can you see a difference in the color of the gums between the two front teeth?” Out of 100 respondents, the overwhelming majority said no and could not tell a difference between the gingival color of the two central incisors when there was 0.25 mm of collapse. In a patient with 0.5 mm of collapse, 84% of respondents said they could not tell the difference in gingival color. However, in a patient with 1.0 mm of collapse with tissue discoloration, about half of respondents said they could see the difference. In research, the threshold of perception becomes when the color difference is noticed by half the group and not visible to the remaining half. Therefore, we found the threshold for perception to be 1.0 mm of collapse with tissue discoloration. Further, in a patient with 1.5 mm of collapse with a very thin phenotype and tissue coloration, almost two-thirds (67%) of respondents said they could see a color difference. The color of the tissue is therefore especially important when there is significant tissue collapse, because without discoloration the collapse tends to be less of an issue and less noticeable to laypeople (Fig 71). To prevent tissue discoloration, bone grafting is recommended at the time of implant placement, and remediation frequently requires some type of connective tissue grafting with or without hard tissue augmentation.

TISSUE ZONE

BONE ZONE

72

Dual-Zone Socket Management Dual-zone socket management refers to the two zones that can be affected when an immediate implant is placed into an extraction socket—(1) the bone zone, which is apical to the head of the implant, and (2) the tissue zone, which is coronal to the head of the implant62 (Fig 72). These two zones could change, recede, and collapse in a buccolingual direction and dimension. The dual-zone socket management technique can minimize the faciopalatal collapse of the ridge, enhance the thickness of the peri-implant soft tissues, and prevent tissue discoloration by

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increasing tissue thickness without using more invasive connective tissue grafting procedures.

Bone graft materials

Autografts An autograft or autogenous graft is a graft composed of the patient’s own bone. It could be harvested from many areas of the mouth, such as the ramus, the tuberosity, the symphysis, or the alveolar ridge. Or it could be harvested from an extraoral site such as the iliac crest, the tibia, or the cranium. For many clinicians, this is still considered the gold standard because the graft will be totally accepted without any possible foreign-body reaction by the patient. Autografts also have the ability to release growth factors as they resorb. This can increase the speed of healing compared with inert materials. They can be used in particulate form or harvested and used as block grafts for larger areas. Autografts can be all cortical or all cancellous in nature or a combination of both. The more cortical the graft, the slower the resorption time. The more cancellous, the quicker the resorption time and the easier it is for the patient’s bone to replace and remodel the graft. Allografts Allografts are grafts transferred between genetically dissimilar members of the same species (ie, other humans or cadavers). They

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43 Dual-Zone Socket Management

The choice of which bone graft material to use for dual-zone grafting has been debated over the last few years. Part of this is because there are now numerous combinations of materials produced by manufacturers. In addition, many clinicians have their favorite or go-to material of choice that they have found works for them over the years. However, sometimes there could be better choices that might produce more consistent outcomes, depending on the final objective of the particular treated area. There are four basic categories of graft materials for use intraorally: autografts, allografts, xenografts, and alloplasts.

are processed in such a way to minimize the antigenicity by freeze drying, radiation, chemicals, or combinations of these processes. In addition, they can be mineralized or demineralized. The most commonly used form in implant dentistry and ridge augmentation is the mineralized form. This is to maintain the space where the graft was placed because it is slower to resorb. It can also be cortical or cancellous or both. The more cortical the bone, the slower it is to resorb. Today, combinations of these forms are being used: cortical, cancellous, demineralized, and mineralized. Some companies have also included collagen material to help bind the particles and help hold the graft in position once placed. In addition, they are made with different sizes (ie, 0.25– 1.0 mm or even larger at 1.0–2.0 mm). The smaller particle sizes resorb faster than the larger sizes. Clearly one can see why this area of grafting materials is sometimes confusing. The particle size (large vs small), composition (mineralized vs demineralized), processing techniques (different chemical processing), and added materials like collagen can each change the patient’s reaction to the graft.

Xenografts Xenografts are grafts taken from another species. The most common source is bovine. These grafts are basically used as a scaffold for the patient’s own bone to fill around while acting as a space maintainer at the same time. These types of grafts are most commonly used for ridge augmentations and sinus elevations, either alone or in combination with autogenous bone or allografts. The main benefit of this material is that it is mostly nonresorbable, so it can be used in areas where maintenance of the shape of a ridge or elevated sinus membrane is desired. Generally it comes in a form interwoven with a collagen matrix that can be sized accordingly and gives it better handling properties during application and adaptation (Figs 73 and 74).

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XENOGRAFT

73

74

THIN PHENOTYPE

4.5 MONTHS

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75

Alloplasts An alloplast is a graft that is composed of synthetic materials. The most common materials are β-tricalcium phosphate (β-TCP), which is resorbable, and hydroxyapatite (HA), which is mostly nonresorbable or very slowly resorbable. The advantage of these materials is that they do not require a second surgical site for harvesting bone and there is no possible antigenic reaction. They have also been used in combination with each other to get the benefits of the two different resorption rates. HA can also be processed in different ways to regulate the speed of resorption. The use of HA is indicated when the clinician wants a space maintainer and a scaffold for bone formation around the particles both in the short and long term, while the use of β-TCP is indicated when quicker resorption and replacement by the patient’s own bone is desired.

Bone graft material for dual-zone therapy The dual-zone therapeutic concept involves the placement of graft material not only into the labial

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76

gap after implant placement (bone zone) but also to the height of the soft tissues (tissue zone).62 It is critical that the correct bone graft material is used in terms of both particle size and type because improper material selection can become a potential irritant to the peri-implant soft tissues. In 2011, Araújo, Linder, and Lindhe published a paper on the histologic response of graft material particles inadvertently encapsulated into the peri-implant soft tissues around extraction socket implants.63 This study used xenograft particles encased in a collagen matrix (Bio-Oss Collagen, Geistlich) and found no inflammatory response when left in the soft tissues. However, the authors of this textbook found the contrary—that using this material for dualzone grafting may be acceptable in the bone zone but is not ideal in the soft tissue zone because the particles do not resorb in a timely manner and hence become an irritant in the long term. Figures 75 and 76 exemplify this in a patient with a thin phenotype right after grafting and after 4.5 months of healing; note the labial fistula because the bone graft particles are trying to exfoliate through the soft tissues. Figure 77 shows graft material entrapped and

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TRAPPED PARTICLES

IRRITATED TISSUES

77

78

45 Dual-Zone Socket Management

79

contained within the soft tissue sulcus of a patient with a thick phenotype. Note that the graft cannot perforate through the thick soft tissues. The use of small-particle mineralized corticocancellous allograft is also a concern when used in the soft tissue zone because the cortical particles slowly resorb and act as an irritant (Fig 78). This type of soft tissue irritation occurred in about 10% of cases. Consequently, the best singular graft material to use in both the bone and soft tissue zones for dual-zone therapy is a small-particle mineralized cancellous allograft. The particles will be able to maintain the ridge volume as a filler and also thicken the soft tissues but will not cause irritation because they will resorb in a timely manner (Figs 79 and 80).

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80

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Prosthetic socket sealing Prosthetic socket sealing is a term and concept described by Trimpou and Weigl almost a decade ago whereby a provisional restoration is used to contain and protect the graft during the healing phase of immediate tooth replacement therapy, as opposed to a strictly surgical approach where membranes are used to cover the treatment site.64 This procedure has been found to be extremely effective as previously noted in regard to esthetic biometric outcomes. With this technique, a custom healing abutment or provisional restoration is used as a prosthetic device to “seal” the socket.

Chapter 2: Management of Type 1 Extraction Sockets

46

Custom healing abutment A custom healing abutment, which is essentially the subgingival component of a provisional crown restoration to the FGM, is a minimum requirement in immediate tooth replacement therapy. Recent research comparing esthetic outcomes of delayed versus immediate temporization shows the benefits of the latter, where less recession and collapse were noticed.65 The custom healing abutment serves as a prosthetic sealing device to contain, protect, and maintain the graft material during healing in the dual-zone socket management technique (Figs 81 to 89). The use of a custom healing abutment is indicated when the insertion torque value is less than 25 Ncm, where the risk of occlusal overloading with a provisional crown restoration is increased.66,67 Provisional crown restoration Successful provisional restoration of postextraction socket implants relies on adequate insertion torque values and primary stability of the implant, preferably at least 35 Ncm. To successfully place a graft using the dual-zone technique with a provisional restoration, one must make the provisional restoration first and then graft the site. The provisional restoration can be fabricated from acrylic or composite resin via an impression taken chairside or fabricated in the laboratory ahead of time. The tooth

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81

Fig 81 The iShell device (BioHorizons/Vulcan Custom Dental) is placed and seated over a PEEK (polyetheretherketone) temporary cylinder. Fig 82 The iShell prosthetic seating instrument (PPIS, Hu-Friedy) is used during placement of the sleeve.

82

Fig 83 Once the iShell is properly seated around the PEEK temporary cylinder, the two components are luted together with either acrylic or composite resin. Note that the resin is used to secure the shell to the temporary cylinder in a few small areas so that the hem is not entrapped in the resin material itself.

Fig 84 The secured iShell is removed entirely with the temporary cylinder, and the hem is washed and steam cleaned away. The small remaining voids are then filled extraorally.

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85

86

Figs 85 and 86 The excess material and iShell, held on a laboratory implant analog, is trimmed, finished, and polished to create the proper contour for the custom healing abutment. The excess PEEK material is removed to the level of the FGM.

Fig 87 The custom healing abutment is removed from the laboratory analog and steam cleaned prior to implant seating intraorally.

47 Dual-Zone Socket Management

Fig 88 The custom healing abutment is used as the prosthetic socket sealing device to contain and protect the graft material during healing.

Fig 89 Healing is uneventful 2 weeks posttreatment.

in question is then atraumatically removed using sharp dissection of the supracrestal gingival fibers with a scalpel to ensure that they are not torn. The socket must be cleaned and debrided completely, and the implant is then placed toward the palatal side of the extraction socket. Once the provisional restoration is made and verified, a flat-contoured healing abutment can be placed. This will allow the bone graft to be placed not only in the bone zone but also in the tissue zone extending almost to the level of the FGM (see Fig 79). The provisional restoration is used as a prosthetic socket sealing device so it can then be screwed and torqued once seated. Screw-retained provisional restorations offer

the advantage of only one subgingival interface with no cement, making this a very predictable procedure. Note that the same protocol can be used with a custom healing abutment as a substitute for a full provisional crown restoration. This is often done if the initial stability of the implant is less than 25 Ncm. Fabrication of a provisional restoration at the time of tooth removal and implant placement provides additional benefits as well, including cosmetic restoration of the tooth and preservation of the proximal contact areas for papilla maintenance. The presence or absence of the interdental papilla as a function of the proximal contact area

Tarnow-Chu_CH02.indd 47

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90

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48

Tarnow-Chu_CH02.indd 48

91

has been well established by Tarnow, Magner, and Fletcher in 1992.68 The benefit of immediate tooth replacement with immediate clinical provisional crown restoration is maintenance of the proximal contact areas, which preserves the papillae heights and positions.69 The risk is that in a highly scalloped gingival form scenario, if the proximal contacts and papillae are not supported, then they may not re-form to their pretreatment height and location if allowed to flatten.

Diagrammatic example of the dual-zone technique with prosthetic socket sealing The dual-zone technique requires that the provisional restoration or custom healing abutment is made prior to grafting because this material occupies the soft tissue zone and fabrication of these prosthetic devices is unrealistic afterward. A diagnostic impression of the tooth is made prior to removal (Fig 90). Autopolymerizing acrylic or composite resin is used to make a tooth-form temporary or shell (Figs 91 and 92). The excess material is trimmed and removed

92

with laboratory burs prior to readaptation and relining (Figs 93 to 95). The fractured tooth must be removed without flap elevation as previously described in this chapter (see Figs 3 to 10). Sharp dissection of the supragingival fibers is performed prior to using fine beak extraction forceps (see Figs 4 to 7). The remaining root fragment must be removed entirely (see Figs 8 to 10). The extraction socket should be debrided thoroughly prior to implant placement. Following proper implant placement in the palatal aspect of the extraction socket, there should be a gap around the facial and proximal sides of the implant (Figs 96 and 97). After implant placement, a polyetheretherketone (PEEK) temporary cylinder is placed to create a screw-retained provisional restoration (Fig 98). The tooth-form shell is hollowed out both proximally and to the incisal edge to create restorative space to reline material over the temporary cylinder (Figs 99 and 100). Acrylic resin is placed onto the temporary cylinder intraorally as well as the shell extraorally, which is then seated over the cylinder (Figs 101 to 103). While the material

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93

94

95

PROBING THE GAP

49

97

PEEK CYLINDER

Dual-Zone Socket Management

96

98

is setting, the shell can be positioned properly and slightly in labioversion to avoid occlusal contact (Fig 104). Care must be taken to prevent restorative material from obliterating the screw

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access channel during polymerization to facilitate removal of the provisional restoration afterward with an implant driver (Figs 105 and 106).

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100

ADDING ACRYLIC

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SEATING

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51 Dual-Zone Socket Management

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107

Once removed, the provisional restoration can be attached to an implant analog, where the contact areas are defined with a red wax pencil (Figs 107 to 111). Additional provisional material can be added to areas of deficiency around the PEEK temporary cylinder (Figs 112 to 114). Gross excess material can be removed using a heatless stone and diamond burs with high- or low-speed rotary instrumentation (Figs 115 to 118). Small voids can be filled in with additional material and the contours evaluated, followed by final finishing and polishing (Figs 119 to 121). Custom unfilled composite resin extrinsic colors or stains can be applied for definitive shade matching (Figs 122 and 123).

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110

111

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CORRECTING DEFICIENCIES

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52 Chapter 2: Management of Type 1 Extraction Sockets

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REMOVAL OF EXCESS MATERIAL

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FINISHING AND POLISHING

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53 Dual-Zone Socket Management

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A flat noncontoured healing abutment is placed onto the implant-abutment interface after provisional restoration fabrication. If a platform-switched provisional crown or custom healing abutment is going to be placed, then a matching healing abutment for grafting should be used (Fig 124). A small-particle mineralized cancellous allograft is mixed with sterile saline (Fig 125), and a sterile amalgam carrier is used to pick up the graft material and place it into the gap (Fig 126). A small curved and narrow bone plugger is used to condense the graft material, and this process is repeated until the gap is filled almost to the level of the FGM (Figs 127 to 129). The gap material is allowed

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GRAFTING THE GAP

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to settle for about 10 minutes to achieve initial clot stability, and then the healing abutment is subsequently removed (Fig 130). The provisional restoration or custom healing abutment

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PROSTHETIC SOCKET SEAL

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is then replaced to contain and seal (prosthetic socket seal) the graft material (Fig 131). The excess material is removed with an explorer or periodontal probe tip, and the restoration is adjusted for nonocclusal contact or loading

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in maximum intercuspal position and lateral excursions (Figs 132 to 134). The graft material is allowed to heal and mature for about 4 to 6 months prior to first disconnection and impression making.

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iShell technique

Diagrammatic example of a custom healing abutment with dual-zone grafting and iShell These illustrations represent the case of a nonrestorable fractured maxillary right central incisor. Sharp dissection is used to sever all supracrestal gingival fibers and facilitate tooth extraction via

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Dual-Zone Socket Management

When replacing nonrestorable teeth with implant restorations, it is critical to mimic the preextraction state of the cervical tooth root surface in order to preserve the natural contours of the soft tissues and bone. However, mucosal tissues start to collapse immediately after tooth extraction, so how can they be maintained? In an attempt to answer this question, the authors of this book worked with industry partners to develop a prefabricated gingival former or sleeve (iShell) that mimics the tooth root cervix in this critical zone70 (see Fig 81). As such, it is only used for immediate provisional restorations. The shell is designed to extend 1.0 mm above the CEJ and 3.0 mm below it from the facial aspect and is 0.3 to 0.5 mm in thickness. These prefabricated shells can be milled to be tooth specific with CAD/CAM systems. This shell allows us to capture the soft tissue profile irrespective of the implant position. In addition, it facilitates easy impression making. Because the shells are prefabricated, a shell with the same size and lot number as that used for provisional restoration can be used for the implant-level impression. Even if the tissue has collapsed, the shell brings it back to its preextraction state. Further, the same shell allows you to wax up a custom-fabricated final abutment for a cement-retained restoration. Therefore, the iShell technique allows a seamless workflow from provisional restoration to impression making to final abutment design. These shells are useful not only for esthetic concerns surrounding maxillary anterior teeth but also for molars (see chapter 5). Preservation of the tissue shape becomes critical to prevent food impaction in posterior teeth.

137

rotation with periodontal elevators—the key is to not disrupt the integrity of the labial plate of bone (Figs 135 to 137). Sounding to the osseous crest should confirm that the facial plate of bone is intact and that the patient has a normal crest. The implant is placed toward the palatal side of the extraction socket, but the peri-implant soft

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iSHELL

TEMPORARY CYLINDER

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tissue will still collapse during this 15-minute procedure. To capture the shape of the tooth root cervix, the iShell is seated into the socket and restores the tissues to their preextraction state (Fig 138). It is important to check the fit of the shell in the socket and make sure that it is the correct size and diameter. The iShell is first placed to ensure that the peri-implant tissues are properly supported circumferentially. The shell also tends to control some of the bleeding, acting like a Band-Aid of sorts. Once the iShell is properly seated—independent of the implant position—a temporary cylinder can be seated through the iShell (Fig 139). Acrylic or composite resin is used to secure the position of the shell to the implant temporary cylinder (Figs 140 and 141). The complex can then be removed

from the implant and attached to a laboratory replica, where additional material can be added to fill in any voids (Figs 142 to 145). The excess material is removed, the complex is finished and polished, and the screw access channel is shortened to the level of the FGM circumferentially, thereby creating the custom healing abutment (Figs 146 to 148). This device is steam cleaned for 20 seconds or cleaned with an alcohol wipe and saline rinse prior to delivery to the implant site (Fig 149). The custom healing abutment allows the tissue to mature and heal for 4 to 6 months prior to first disconnection and impression making (Fig 150). At a very minimum, a custom healing abutment should be made after immediate implant placement in an extraction socket.

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FIRST DISCONNECTION

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CUSTOM HEALING ABUTMENT

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Diagrammatic example of a full provisional restoration with dual-zone grafting and iShell The illustrations depicted in Figs 151 to 170 represent removal of a failing maxillary left central incisor due to an internal resorption lesion. The same techniques previously described in this chapter are used for atraumatic tooth removal and implant placement, the only difference being that the fabrication of the provisional restoration is combined with the iShell technique (see Fig 156). This process is streamlined because the subgingival cervical portion is already prefabricated and created, thereby reducing the amount of time and effort required to fill in voids and trim the restoration (see Figs 160 to 163). The graft is placed according to the dual-zone protocol, and the full provisional restoration is used as the prosthetic socket sealing device.

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NO BLEEDING

EPITHELIAL CELLS

FIBROBLASTS

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Sulcular Bleeding at First Disconnection of an Implant Healing Abutment The presence of bleeding upon removal of the provisional restoration seems to be an important factor for successful esthetic outcomes. In a recent study, it was found that bleeding was the surrogate for cell adherence to the provisional restoration surface that acted as a platform for this process to occur. This study on bleeding went beyond histology and sought to measure the soft tissue and dimensional ridge changes that took place in the presence or absence of bleeding.71 The data showed that when there was bleeding, there was almost no change in tissue dimensions, especially if a graft had been placed. This led to the conclusion that, for best results, the healing abutment and provisional restoration should be left alone long enough for

the epithelium and connective tissues to attach to the provisional restoration and mature. From an esthetic standpoint, if this attachment onto the abutment or provisional restoration can be captured during initial healing with an immediate extraction socket, then we may be looking at a different paradigm. The question is what type of cells adhere to the acrylic resin surface. Cell surface histology performed by Hanae Saito at the University of Maryland using immunofluorescence labeling showed differences between epithelial cells and fibroblasts. Figure 171 shows the surface of a provisional restoration under scanning electron microscopy when there was no bleeding and consequently no cells. Figure 172 shows the surface with epithelial cells, and Fig 173 shows the surface with fibroblasts. Clinically, fibroblasts can adhere to the surface of restorative materials provided that the surface is clean and microporous, which allows the cells to physically grasp on (Figs 174 to 176).

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Figures 177 and 178 show a clinical example where a biopsy was taken to the osseous crest on the palatal side of gingival tissues adjacent to an acrylic resin custom healing abutment. The patient showed bleeding and a vascular bed at the base of the tissue biopsy (Figs 179 to 181). Hematoxylin and eosin stain show blood vessels in the connective tissue layer contiguous with the acrylic resin surface (Fig 182). This is histologic proof that connective tissue can grow onto a restorative material surface and the reason why the authors’ clinical study showed less recession and collapse when bleeding was seen at first abutment disconnection.

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Sulcular Bleeding at First Disconnection of an Implant Healing Abutment

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Cement- Versus ScrewRetained Provisional and Definitive Restorations

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A screw-retained provisional restoration is superior over cementation, especially postsurgery, to avoid introducing cement unintentionally into the surgical site (Figs 183 and 184). In addition, screw-retained provisional and definitive restorations have the distinct advantage that they have only one subgingival interface—the abutment-implant interface—which is a more advantageous prosthetic design because there is only one potential area of micromovement and microleakage. Cement-retained provisional restorations have two interfaces—the abutmentimplant interface and the crown-abutment interface—as well as the potential for residual cement.

Abutment Selection: Materials and Color Considerations Abutment selection is one of the most critical steps from the restorative and esthetic perspective because it involves the color and strength of the material selected. In the advent of platform switching, it is important to be mindful of the strength of the abutment-crown assembly in the selection process because the prosthetic connection is smaller in diameter and potentially diminished in resistance to forces of occlusion. Jung et al showed that the horizontal thickness of peri-implant soft tissues is important in the masking ability of different-colored substrate materials; roughly 2.5 mm is required to block shine-through of a gray-colored abutment.33 When 1.5 mm or less of tissue is present, then ceramics is a good materials choice from a color perspective (Fig 185). Park and Ishikawa-Nagai showed that light-yellow or pink-colored abutments have the least negative effect on changing the color

183 CEMENT IN SURGICAL SITE

184 CERAMIC ABUTMENT

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of the soft tissues.55,56 The authors of this book frequently employ seminoble or noble metalceramic restorations for two reasons: (1) ceramic buildup layering for anterior tooth shade matching and (2) the ability to gold plate the alloy to achieve a light-yellow color of the peri-implant soft tissues (Figs 186 and 187).

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METAL ABUTMENT

GOLD PLATING

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place a membrane because the opening is very small and of course the crest of bone is still intact, as in type 1 cases. Usual gap grafting is performed, making sure that the apical area is filled with material.

Periapical lesions and fistulae

Ankylosed teeth

The question of how to manage teeth with periapical lesions is often asked when deciding when and if to place an immediate implant in cases with preexisting active periapical disease with a fistula.72 The concern is real and must be treated with extra caution. Ideally a CBCT scan should be taken to evaluate the extent of the lesion in three dimensions. This is important because many times the periapical radiograph reveals neither the extent of the bone lesion nor the amount of remaining bone, which is required data if an implant is going to be placed. The positive is that most of these apical lesions are on the facial aspect of the root. This means that after very thorough debridement and irrigation of the socket, an implant may still be able to be placed, because generally implants are placed toward the palatal side of the socket wall. In this circumstance, the apical lesion does not negatively affect the normal placement of the implant. If a fistula is present on the labial, the clinician can use a hand instrument to determine how large the opening is in the bone intrasocket. In most cases, there is no need to

The management of ankylosed teeth and their removal depends on where the ankylosis is located. The most problematic area would be fusion at the thin labial plate of bone. This usually means that extraction will cause the loss of the buccal plate of bone, making it a problem to place the implant that day if the tooth is in the esthetic zone (see chapter 3). A solution that is receiving increasing attention and being used more frequently is the concept of the socket-shield procedure.73–76 That is because the buccal piece of bone is bound to the surrounding bone and is therefore not extracted but left remaining in the socket. The implant is therefore placed to the lingual aspect of the residual root or shield, and then the gap between the implant and tooth can be grafted. A major concern with this procedure is that it is highly technique sensitive and should be performed by a highly skilled, experienced, and advanced clinician. In addition, it requires more time to perform the partial extraction of this root fragment. However, it may be the procedure of choice in the future for

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65 Management of Teeth with Periapical Lesions, Fistulae, and Ankylosis

Management of Teeth with Periapical Lesions, Fistulae, and Ankylosis

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certain ankylosed teeth, for multiple adjacent tooth replacement in the esthetic zone to maintain the interdental papillae, or for teeth that have dehiscence defects on the labial surface. If there is no pocket depth on the buccal, then this procedure may be able to prevent the collapse of the soft tissue after removal of the tooth. This may in fact be the ideal indication to utilize this treatment modality; however, additional short- and long-term research is required before we can recommend this technique for routine use.

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Implant Design for Immediate Placement Tapered vs cylindrical implants, thread design, and thread pitch The macroscopic design of implants is one of the key distinguishing factors that implant companies feature because it allows them to define product differentiation among their competitors for marketing. That being said, there are some key factors that would help in situations requiring immediate implant placement. One of the most common modifications that manufacturers offer is a tapered design implant. The results of studies show that a tapered implant has better initial stabilization compared with the same implant that is cylindrical.77 This is certainly important because in immediate socket placement and temporization it is critical to achieve as much stability as possible so that there is minimal chance of movement of the surrounding bone during the initial healing phase. Along with the taper, another very important feature of implants for immediate tooth replacement therapy is an aggressive thread design, namely threads that are very deep and self-tapping. Not unlike a carpenter’s wood screw, this feature will also increase the surface area of the implant, which is partially lost in a tapered shape. For every millimeter of

diameter decrease in the implant width, about 25% of the surface area is lost. Therefore, these deep aggressive threads serve two purposes: increased stability and greater surface area for the implant. The thread pitch or distance between threads is another characteristic of many implants that allows differentiation among them. Most implants have about 0.6 mm between each thread. This means that one turn of the implant will allow the depth to go into the bone by the same distance as the pitch of the threads. This pitch is sometimes increased for more aggressive placement in softer bone because there is less chance of stripping the bone as the implant proceeds into the bone. It also means that tapping is not needed, especially for softer bone. In addition, a common clinical technique is to undersize the osteotomy in poor-quality bone to achieve higher primary stability with a tapered implant with deeper threads, thread pitch, and self-tapping ability.78

Platform switching Platform switching, by definition, is placing a smaller-diameter abutment on a largerdiameter implant surface. This concept was first described over a decade ago by Lazzara and Porter and confirmed by the work of Canullo et al.79,80 This design in concept moves the horizontal component of the zone of irritation from prosthetic micromotion and bacterial leakage in a medial direction, therefore theoretically reducing the amount of crestal bone loss (Figs 188 and 189). Hundreds of articles have been published since that time touting or refuting the benefits of this implant-abutment interface design. Several research articles by Linkevicius’s group clearly showed that the vertical soft tissue height or implant depth were the key elements in being able to benefit from this design concept. The importance of implant depth or soft tissue height is all about biology, where the body is allowed to re-form the dentogingival complex above the implant platform81–84 (Fig 190). Biologically, teeth require

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Fig 188 There is both a horizontal and vertical zone of inflammation around the implant-abutment interface of bone-level implants due to micromotion and microleakage of the abutment at this junction.

Fig 189 Theoretically, with platform switching the horizontal component or zone of irritation or inflammation is moved medially, thereby having less of a negative effect on marginal bone loss.

67 Implant Design for Immediate Placement

Fig 190 Diagrammatic representation of re-established biologic width after abutment connection and restoration on a non– platform-switched implant relative to thin vertical soft tissue thickness. CT, connective tissue.

this distance, and this research confirms that the same is true for dental implants. Platform switching or mismatching is used because it allows the biologic width to be partly on the horizontal shoulder of the implant instead of just vertically down the side of the implant when implants are placed at the proper depth from the soft tissue margin; its intent is to

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preserve bone. With this thought of horizontal mismatch, there is more room for the bone to protect itself, and soft tissue can cover over part of the implant platform. Platform switching therefore minimizes midfacial tissue recession and reduces the chance of injuring the buccal bone plate because the attachment apparatus rests on the implant platform.85

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SUPRACRESTAL BIOLOGIC WIDTH

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Figures 191 and 192 show supracrestal biologic width being achieved around implants with platform switching. There is connective tissue and epithelial attachment on the abutments. When a healing abutment is detached, sulcus bleeding is frequently seen because the junctional epithelium and connective tissue fibers that had adhered to the abutment interface are ripped (Figs 193 and 194). After a few disconnections and impression making, this bleeding stops because the epithelium has migrated to the implant platform and is no longer attached to the abutment. The idea is to try to keep it there, hence the “one abutment, one time” concept. In 2009, Rodriguez-Ciurana et al showed that instead of the 1.5 mm of interimplant tissue loss with traditional implant placement and restoration, platform switching resulted in only 0.5 mm of tissue loss.86 Platform switching therefore allows implants to be placed closer together without losing crestal bone. For small lateral incisors and other areas with compromised space, 0.5 mm may be the difference between whether or not orthodontic therapy would be considered to increase the edentulous

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space. With platform switching, there may be enough crestal distance without employing orthodontics and potentially injuring the adjacent tooth because with this technique adjacent implants can be as close together as 2.0 mm with interdental bone maintenance.87

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One abutment, one time

Coaxial versus straight implants Screw-retained restorations require precision in placement with straight implants so that the screw access channel exits from the restorative cingulum area. However, precautions exist with edentulous and anterior extraction sites using straight implant designs, where the literature reports the risk of apical perforation at 20% and 82%, respectively, due to the inherent anatomy of the anterior maxilla.89 The anatomy of the anterior maxilla is such that 80% of the time the bone is apical and palatal to the roots of anterior teeth.90–92 Therefore, delayed implant placement, cement-retained restorations, angulated screw channel abutments, and dynamic or static surgical guides are all strategies to avoid this problem. A clever restorative option to eliminate the use of guides and cementation of provisional and definitive restorations is to use a coaxial implant design (Co-Axis, Southern Implants), where the

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CO-AXIS IMPLANT

angle correction is at the implant or subcrestal level versus the abutment or supracrestal position93 (Fig 195). The original development in 2002 was derived from the use of zygomatic implants and adapted for dentoalveolar applications with the intent to provide noninvasive options to eliminate surgical procedures such as sinus augmentation while delivering a screwretained restoration option without perforation of the buccal plate (Fig 196). These implants are created with either a 12-, 24-, or 36-degree angle correction, thereby preventing dehiscence and fenestration and allowing screw-retained restorations. The 12-degree implant is particularly useful for patients whose bone shape dictates placing the implant in an anteroposterior apical direction, which is quite common in the anterior maxilla sextant (from premolar to premolar). These implants arrive constructed with the implant mount or driver preattached to the implant-abutment interface with a matching degree offset so that the implant spins at zero degrees during insertion (Fig 197).

Inverted body-shift design implant

69 Implant Design for Immediate Placement

It would be ideal to maintain the seal of the original healing abutment at the time of tooth removal and implant placement, thereby ensuring tissue stability and maturity. However, delivering the definitive restoration at the time of implant placement, while not impossible with today’s advances in digital planning and technology, is challenging. Therefore, most cases require multiple removals and replacements of abutments and restorations throughout treatment. As long as enough time is allowed for the tissue to heal in an extraction socket (3 to 4 months), bleeding still occurs and the connective tissue in the free gingiva is mature enough to withstand epithelial detachment with little tissue change. Degidi et al in 2011 showed only 0.1 mm more bone loss over a 3-year period with the “one abutment, one time” concept compared with the test group of four abutment disconnections with a platformswitched implant design.88 Consequently, platform switching also helps to maintain tissue with multiple abutment disconnections.

12-DEGREE IMPLANT

Today, the pendulum has swung toward treatment outcomes that focus more on esthetic results, such as the pink esthetic score, and less on implant survival or osseointegration.94 It has been well established, understood, and

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accepted that the thickness of the labial bone plate and soft tissues in the anterior maxilla are extremely thin (1.0 mm or less), which increases the risk of esthetic dilemmas.6,7,11,12 From a biologic perspective, thin avascular labial bone of 1.0 mm or less in dimension can survive around natural teeth because the adjacent PDL is highly vascular and provides nourishment to this area, in addition to the overlying periosteum. Of equal importance, bone surrounding an implant after placement must be adequate in quantity and volume; studies support a minimum of 1.5 to 2.0 mm in width for biologic reasons to result in long-term stability and ultimately esthetics.11,12 The danger is that if inadequate bone (1.5 mm or less) exists around the implant after placement, then it may not survive and may succumb to avascular necrosis because endosteum or marrow is not present. Also, changes in craniofacial growth and development may lead to an esthetic issue around implants in the long term.95 Hence, narrower implants must be considered, but they are less effective in achieving high primary stability than wider-diameter implants.8,9 Length is an alternative strategy, but there is a limit to the amount of apical bone beyond an extraction socket before encroaching upon the floor of the nasal antrum.91 Implant diameter has been shown to be more effective in achieving primary stability than length, especially in soft-quality bone where undersizing the osteotomy is an essential and useful clinical approach.78 However, with wider-diameter tapered implant designs (divergent wider coronal portion), the labial gap distance is reduced and the tooth-to-implant distance is compromised, especially between the central and lateral incisors, leading to interdental papilla loss in extraction sockets.96,97 The horizontal formation of biologic width even with platform-switched designs and/or pressure necrosis of thin avascular crestal bone can be causative factors.98 The reality is that the requirements of modern-day implants for biologic and ultimately esthetic needs are no longer the same as those in the 1980s when P-I

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Brånemark first introduced the concept of osseointegration to North America from Sweden, where integration and survival were the prime directives of treatment. An innovative macro hybrid design (Inverta, Southern Implants) has recently been developed to mitigate the problems of width and length to accomplish the “best of both worlds.” This design combines a tapered apical portion with a cylindrical coronal portion, all in a singular body (Figs 198 and 199). Recent preclinical and clinical studies evaluating this design have been reported,99,100 and this unique body-shift

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great potential for wound healing. The clinical study on 33 implants in the same number of patients showed that a labial bone dimension of 1.6 to 2.0 mm, an interdental distance of 2.4 to 2.6 mm, and a pink esthetic score of 12.5 was achieved up to 1-year follow-up.100 This hybrid implant design is available in straight, coaxial, wide, and ultrawide versions.

Critical Points to Remember

concept in diameter and shape is truly a paradigm shift. The overall configuration of the implant is inverted and convergent in form toward the implant-abutment interface, where the bone is thinnest, delicate, and avascular, as opposed to being divergent or wider as in most implant designs (see Fig 198). Conversely, the tapered apical portion is wider where the bone is greatest in quantity and vascularity. By reducing the coronal diameter of the implant with the inverted body-shift design, pressure is not exerted on the thin avascular crest of bone circumferentially. In addition, greater space is inherently generated that allows more graft material to be placed, not only labially but also interdentally into the gap, to create a net increased bone dimension (Figs 200 and 201). The preclinical animal study showed no evidence of apical pressure necrosis with consistent insertion values of 100 Ncm of torque on roughly three-quarters of the implant placed. The results of this histomorphometric study showed that high insertion torque of 100 Ncm will not cause pressure necrosis because the apical portion of the extraction socket not only possesses the greatest amount of bone volume but also is rich in marrow, which has

Wide-body versus regular-width implants For information on wide-body (> 6.0 mm) versus regular-width implants, see chapter 5.

Critical Points to Remember • Bone grafting is important for esthetic reasons only and does not affect osseointegration or implant survival. • The provisional restoration is a critical component because it serves as a prosthetic socket sealing device. If the bone graft within the socket can be prosthetically protected during the healing phase, there will be less

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tissue collapse, even in patients with a thin periodontal phenotype. • The dual-zone socket management technique is a simple method that uses a bone graft in combination with the provisional restoration to minimize ridge collapse to less than 0.2 mm, increase peri-implant soft tissue thickness by 1.0 mm without a connective tissue graft, and decrease the risk and incidence of tissue discoloration. • The provisional restoration and definitive abutment/crown restoration surface must be clean or disinfected before it is inserted into the patient’s mouth. • Having greater than 1.0 mm of tissue collapse with discoloration seems to be the visual perception threshold for unacceptable esthetic outcomes; the key element is to prevent this from happening because it is the whistleblower for esthetic success.

References 1. Merheb J, Vercruyssen M, Coucke W, Beckers L, Teughels W, Quirynen M. The fate of buccal bone around dental implants. A 12-month postloading follow-up study. Clin Oral Implants Res 2017;28:103–108. 2. Chen ST, Buser D. Clinical and esthetic outcomes of implants placed in postextraction sites. Int J Oral Maxillofac Implants 2009;24(suppl):186–217. 3. Caneva M, Botticelli D, Vigano P, Morelli F, Rea M, Lang NP. Connective tissue grafts in conjunction with implants installed immediately into extraction sockets. An experimental study in dogs. Clin Oral Implants Res 2013;24:50–56. 4. Huynh-Ba G, Pjetursson BE, Sanz M, et al. Analysis of the socket bone wall dimensions in the upper maxilla in relation to immediate implant placement. Clin Oral Implants Res 2010;21:37–42. 5. Braut V, Borenstein MM, Belser U, Buser D. Thickness of the anterior maxillary facial bone wall – A retrospective radiographic study using cone beam computed tomography. Int J Periodontics Restorative Dent 2011;31:125–131. 6. Cook RD, Mealey BL, Verrett RG, et al. Relationship between clinical periodontal biotype and labial plate thickness: An in vivo study. Int J Periodontics Restorative Dent 2011;31:345–354. 7. Araújo MG, Sukekava F, Wennstrom JL, Lindhe J. Ridge alterations following implant placement in fresh extraction sockets: An experimental study in the dog. J Clin Periodontol 2005;32:645–652.

8. Caneva M, Salata LA, de Souza SS, Baffone G, Lang NP, Botticelli D. Influence of implant positioning in extraction sockets on osseointegration: Histomorphometric analyses in dogs. Clin Oral Implants Res 2010;21:43–49. 9. Caneva M, Salata LA, de Souza SS, Bressan E, Botticelli D, Lang NP. Hard tissue formation adjacent to implants of various size and configuration immediately placed into extraction sockets: An experimental study in dogs. Clin Oral Implants Res 2010;21:885–890. 10. de Oliveira Rosa ACP, da Rosa JCM, Dias Pereira LAV, Francischone CE, Sotto-Maior BS. Guidelines for selecting the implant diameter during immediate implant placement of a fresh extraction socket: A case series. Int J Periodontics Restorative Dent 2016;36: 401–407. 11. Spray JR, Black CG, Morris HF, Ochi S. The influence of bone thickness on facial marginal bone response: Stage 1 placement through stage 2 uncovering. Ann Periodontol 2000;5:119–128. 12. Chappuis V, Rahman L, Buser R, Janner S, Belser U, Buser D. Effectiveness of contour augmentation with guided bone regeneration: 10-year results. J Dent Res 2018;97:266–274. 13. Pluemsakunthai W, Le B, Kasugai S. Effect of buccal gap distance on alveolar ridge alteration after immediate implant placement: A microcomputed tomographic and morphometric analysis in dogs. Implant Dent 2015;24:70–76. 14. Grunder U, Gracis S, Capelli M. Influence of the 3-D bone-to-implant relationship on esthetics. Int J Periodontics Restorative Dent 2005;25:113–119. 15. Lekovic V, Kenney EB, Weinlaender M, et al. A bone regenerative approach to alveolar ridge maintenance following tooth extraction. A report of 10 cases. J Periodontol 1997;68:563–570. 16. Lekovic V, Camargo PM, Klokkevold PR, et al. Preservation of alveolar bone in extraction sockets using bioabsorbable membranes. J Periodontol 1998;69: 1044–1049. 17. Camargo PM, Lekovic V, Weinlaender M, et al. Influence of bioactive glass on changes in alveolar process dimensions after exodontia. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;90:581–586. 18. Iasella JM, Greenwell H, Miller RL, et al. Ridge preservation with freeze-dried bone allograft and a collagen membrane compared to extraction alone for implant site development: A clinical and histologic study in humans. J Periodontol 2003;74:990–999. 19. Serino G, Biancu S, Iezzi G, Piattelli A. Ridge preservation following tooth extraction using a polylactide and polyglycolide sponge as space filler: A clinical and histological study in humans. Clin Oral Implants Res 2003;14:651–658. 20. Schropp L, Wenzel A, Kostopoulos L, Karring T. Bone healing and soft tissue contour changes following single-tooth extraction: A clinical and radiographic 12-month prospective study. Int J Periodontics Restorative Dent 2003;23:313–323.

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35. Patil R, van Brakel R, Iyer K, Huddleston Slater J, de Putter C, Cune M. A comparative study to evaluate the effect of two different abutment designs on soft tissue healing and stability of mucosal margins. Clin Oral Implants Res 2013;24:336–341. 36. Patil RC, den Hartog L, van Heereveld C, Jagdale A, Dilbaghi A, Cune MS. Comparison of two different abutment designs on marginal bone loss and soft tissue development. Int J Oral Maxillofac Implants 2014;29:675–681. 37. Patil R, den Hartog L, Dilbaghi A, de Jong B, Kerdijk W, Cune MS. Papillary fill response in single-tooth implants using abutments of different geometry. Clin Oral Implants Res 2016;27:1506–1510. 38. Patil R, Gresnigt MMM, Mahesh K, Dilbaghi A, Cune MS. Esthetic evaluation of anterior single-tooth implants with different abutment designs—Patients’ satisfaction compared to dentists’ observations. J Prosthodont 2017;26:395–398. 39. Saito H, Chu SJ, Zamzok J, et al. Flapless postextraction socket implant placement: The effects of a platform switch-designed implant on peri-implant soft tissue thickness—A prospective study. Int J Periodontics Restorative Dent 2018;38(suppl):S1–S9. 40. Seibert JS, Louis JV. Soft tissue ridge augmentation utilizing a combination onlay-interpositional graft procedure: A case report. Int J Periodontics Restorative Dent 1996;16:310–321. 41. Langer B, Calagna L. The subepithelial connective tissue graft. J Prosthet Dent 1980;44:363–367. 42. Langer B, Calagna L. The subepithelial connective tissue graft: A new approach to the enhancement of anterior cosmetics. Int J Periodontics Restorative Dent 1982;2:23–33. 43. Olsson M, Lindhe J. Periodontal characteristics in individuals with varying forms of the upper central incisors. J Clin Periodontol 1991;18:78–82. 44. Olsson M, Lindhe J, Marinello CP. The relationship between crown form and clinical features of the gingiva in adolescents. J Clin Periodontol 1993;20: 570–577. 45. Kan JY, Rungcharassaeng K, Umezu K, Kois JC. Dimensions of peri-implant mucosa: An evaluation of maxillary anterior single implants in humans. J Periodontol 2003;74:557–562. 46. Carlsson L, Röstlund T, Albrektsson B, Albrektsson T. Implant fixation improved by close fit. Cylindrical implant-bone interface studied in rabbits. Acta Orthop Scand 1988;59:272–275. 47. Gotfredsen K, Warrer K, Hjørting-Hansen E, Karring T. Effect of membranes and porous hydroxyapatite on healing in bone defects around titanium dental implants: An experimental study in monkeys. Clin Oral Implants Res 1991;2:172–178. 48. Knox R, Caudill R, Meffert R. Histologic evaluation of dental endosseous implants placed in surgically created extraction defects. Int J Periodontics Restorative Dent 1991;11:364–375. 49. Stentz WC, Mealey BL, Nummikoski PV, Gunsolley JC, Waldrop TC. Effects of guided bone regeneration around commercially pure titanium and hydroxyapatite-coated dental implants. I. Radiographic analysis. J Periodontol 1997;68:199–208.

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21. Grunder U. Crestal ridge width changes when placing implants at the time of tooth extraction with and without soft tissue augmentation after a healing period of 6 months: Report of 24 consecutive cases. Int J Periodontics Restorative Dent 2011;31:9–17. 22. Vera C, De Kok IJ, Reinhold D, et al. Evaluation of buccal alveolar bone dimension of maxillary anterior and premolar teeth: A cone beam computed tomography investigation. Int J Oral Maxillofac Implants 2012;27: 1514–1519. 23. Brownfield LA, Weltman RL. Ridge preservation with or without an osteoinductive allograft: A clinical, radiographic, micro-computed tomography, and histologic study evaluating dimensional changes and new bone formation of the alveolar ridge. J Periodontol 2012;83:581–589. 24. Degidi M, Nardi D, Daprile G, Piattelli A. Buccal bone plate in the immediately placed and restored maxillary single implant: A 7-year retrospective study using computed tomography. Implant Dent 2012;21: 62–66. 25. Linkevicius T, Apse P, Grybauskas S, Puisys A. The influence of soft tissue thickness on crestal bone changes around implants: A 1-year prospective controlled clinical trial. Int J Oral Maxillofac Implants 2009;24:712–719. 26. Wadhwani C, Piñeyro A. A technique for controlling the cement for an implant crown. J Prosthet Dent 2009;102:57–58. 27. Cooper LF, Raes F, Reside GJ, et al. Comparison of radiographic and clinical outcomes following immediate provisionalization of single-tooth dental implants placed in healed alveolar ridges and extraction sockets. Int J Oral Maxillofac Implants 2010;25: 1222–1232. 28. Du JK, Li HY, Wu JH, Lee HE, Wang CH. Emergence angles of the cementoenamel junction in natural maxillary anterior teeth. J Esthet Restor Dent 2011;23:362–370. 29. Su H, Gonzalez-Martin O, Weisgold AS, Lee EA. Considerations of implant abutment and crown contour: Critical contour and sub-critical. Int J Periodontics Restorative Dent 2010;30:335–343. 30. Steigmann M, Monje A, Chan HL, Wang HL. Emergence profile design based on implant position in the esthetic zone. Int J Periodontics Restorative Dent 2014;34:559–563. 31. Chu SJ, Kan JYK, Lee EA, et al. Restorative emergence profile for single tooth implants in healthy periodontal patients: Clinical guidelines and decision-making strategies. Int J Periodontics Restorative Dent (in press). 32. Weisgold AS. Contours of the full crown restoration. Alpha Omegan 1977;70:77–89. 33. Jung RE, Sailer I, Hämmerle CH, Attin T, Schmidlin P. In vitro color changes of soft tissues caused by restorative materials. Int J Periodontics Restorative Dent 2007;27:251–257. 34. Van Brakel R, Noordmans HJ, Frenken J, De Roode R, De Wit GC, Cune MS. The effect of zirconia and titanium implant abutments on light reflection of the supporting soft tissues. Clin Oral Implants Res 2011;22:1172–1178.

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Chapter 2: Management of Type 1 Extraction Sockets

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50. Akimoto K, Becker W, Persson D, Baker DA, Rohrer MD, O’Neal RB. Evaluation of titanium implants placed into simulated extraction sockets: A study in dogs. Int J Oral Maxillofac Implants 1999;14:351–360. 51. Tarnow DP, Chu SJ. Human histologic verification of osseointegration of an immediate implant placed in a fresh extraction socket with excessive gap distance without primary flap closure, graft or membrane: A case report. Int J Periodontics Restorative Dent 2011;31:515–521. 52. Rosenlicht J, Tarnow DP. Human histologic evidence of integration of loaded HA implant in an augmented maxillary sinus. J Oral Implantol 1999;25:7–10. 53. Tarnow DP, Chu SJ, Salama MA, et al. Flapless postextraction socket implant placement in the esthetic zone: Part 1. The effect of bone grafting and/or provisional restoration on facial-palatal ridge dimensional change—A retrospective cohort study. Int J Periodontics Restorative Dent 2014;34:323–331. 54. Chu SJ, Salama MA, Garber DA, et al. Flapless postextraction socket implant placement: Part 2. The effect of bone grafting and/or provisional restoration on peri-implant mucosal tissue height and thickness—A retrospective study. Int J Periodontics Restorative Dent 2015;35:1–10. 55. Park SE, DaSilva JD, Weber HP, Ishikawa-Nagai S. Optical phenomenon of peri-implant soft tissue. Part I. Spectrophotometric assessment of natural tooth gingiva and peri-implant mucosa. Clin Oral Implants Res 2007;18:569–574. 56. Ishikawa-Nagai S, DaSilva JD, Weber HP, Park SE. Optical phenomenon of peri-implant soft tissue. Part II. Preferred implant neck color to improve soft tissue esthetics. Clin Oral Implants Res 2007;18:575–580. 57. Benic GI, Scherrer D, Sancho-Puchades M, Thoma DS, Hämmerle CHF. Spectrophotometric and visual evaluation of peri-implant soft tissue color. Clin Oral Implants Res 2017;28:192–200. 58. Chu SJ, Saito H, Reynolds MA, et al. Flapless postextraction socket implant in the esthetic zone. Part 3: The effect of bone grafting and/or provisional restoration on peri-implant tissue color stability—A retrospective study. Int J Periodontics Restorative Dent 2018;38:509–516. 59. Johnston WM, Kao EC. Assessment of appearance match by visual observation and clinical colorimetry. J Dent Res 1989;68:819–822. 60. Ghinea R, Perez MM, Herrera LJ, Rivas MJ, Yebra A, Paravina JD. Color difference thresholds in dental ceramics. J Dent 2010;38(suppl 2):e57–e64. 61. Sailer I, Fehmer V, Ioannidis A, Hämmerle CH, Thoma DS. Threshold value for the perception of color changes of human gingiva. Int J Periodontics Restorative Dent 2014;34:757–762. 62. Chu SJ, Salama MA, Salama H, et al. The dual-zone therapeutic concept of managing immediate implant placement and provisional restoration in anterior extraction sockets. Compend Contin Educ Dent 2012;33:524–532,534. 63. Araújo MG, Linder E, Lindhe J. Bio-Oss Collagen in the buccal gap at immediate implants: A 6-month study in the dog. Clin Oral Implants Res 2011;22:1–8.

64. Trimpou G, Weigl P, Krebs M, Parvini P, Nentwig HG. Rationale for esthetic tissue preservation of a fresh extraction socket by an implant treatment concept simulating a tooth replantation. Dent Traumatol 2010;26:105–111. 65. Crespi R, Capparé P, Crespit G, Romanos GE, Gherlone E. Tissue remodeling in immediate versus delayed prosthetic restoration in fresh socket implants in the esthetic zone. Int J Periodontics Restorative Dent 2018;38(suppl):S97–S103. 66. Norton MR. The influence of low insertion torque on primary stability, implant survival, and maintenance of marginal bone levels: A closed-cohort prospective study. J Oral Maxillofac Implants 2017;32:849–857. 67. Levin BP. The correlation between immediate implant insertion torque and implant stability quotient. Int J Periodontics Restorative Dent 2016;36:833–840. 68. Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol 1992;63:995–996. 69. Steigmann M, Cooke J, Wang HL. Use of the natural tooth for soft tissue development: A case series. Int J Periodontics Restorative Dent 2007:27:603–608. 70. Chu SJ, Hochman MN, Tan-Chu JHP, Mieleszko AJ, Tarnow DP. A novel prosthetic device and method for guided tissue preservation of immediate postextraction socket implants. Int J Periodontics Restorative Dent 2014;34(suppl):S9–S17. 71. Saito H, Chu SJ, Reynolds MA, Tarnow DP. Provisional restorations used in immediate implant placement provide a platform to promote peri-implant soft tissue healing: A pilot study. Int J Periodontics Restorative Dent 2016;36:47–52. 72. Novaes AB Jr, Muglia VA, Ramos, UD, Reino DM, Ayub LG. Immediate implants in extraction sockets with periapical lesions: an illustrated review. J Osseointegr 2013;5(3):45–52. 73. Hürzeler MB, Zuhr O, Schupbach P, Rebele SF, Emmanouilidis N, Fickl S. The socket-shield technique: A proof-of-principle report. J Clin Periodontol 2010;37:855–862. 74. Bäumer D, Zuhr O, Rebele S, Hürzeler M. Socket shield technique for immediate implant placement—Clinical, radiographic and volumetric data after 5 years. Clin Oral Implants Res 2017;28:1450–1458. 75. Gluckman H, Salama MA, Du Toit J. A retrospective evaluation of 128 socket-shield cases in the esthetic zone and posterior sites: Partial extraction therapy with up to 4 years follow-up. Clin Implant Dent Relat Res 2018;20:122–129. 76. Kan JYK, Rungcharassaeng K. Proximal socket shield for interimplant papilla preservation in the esthetic zone. Int J Periodontics Restorative Dent 2013;33: e24–e31. 77. Bilhan H, Geckill O, Mumcu E, Bozdag E, Sunbuloglu E, Kutay O. Influence of surgical technique, implant shape, and diameter on the primary stability in cancellous bone. J Oral Rehabil 2010;37:900–907. 78. Barikani H, Rashtak S, Akbari S, Badri S, Daneshparvar N, Rokn A. The effect of implant length and diameter on the primary stability in different bone types. J Dent 2013;10:449–455.

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89. Sung CE, Cochran DL, Cheng WC, et al. Preoperative assessment of labial bone perforation for virtual immediate implant surgery in the maxillary esthetic zone. J Am Dent Assoc 2015;146:808–819. 90. Kan JYK, Roe P, Rungcharassaeng K, et al. Classification of sagittal root position in relation to the maxillary anterior osseous housing for immediate implant placement: A cone beam computed tomography study. Int J Oral MaxIllofac Implants 2011;26: 873–876. 91. Lau SL, Chow J, Li W, Chow LK. Classification of maxillary central incisors—Implications for immediate implant in the esthetic zone. J Oral Maxillofac Surg 2011;69:142–153. 92. Gluckman H, Pontes CC, Du Toit J. Radial plane tooth position and bone wall dimensions in the anterior maxilla: A CBCT classification for immediate implant placement. J Prosthet Dent 2018;120:50–56. 93. Howes DG. Angled implant design to accommodate screw-retained implant-supported prostheses. Compend Contin Educ Dent 2017;38:458–464. 94. Furhauser R, Florescu D, Benesch T, Haas R, Mailath G, Watzek G. Evaluation of soft tissue around single-tooth implant crowns: The pink esthetic score. Clin Oral Implants Res 2005;16:639–644. 95. Daftary F, Mahallati R, Bahat O, Sullivan RM. Lifelong craniofacial growth for osseointegrated implants. Int J Oral Maxillofac Implants 2012;28:163–169. 96. Esposito M, Ekestubbe A, Grondahl K. Radiological evaluation of marginal bone loss at tooth sites facing single Branemark implants. Clin Oral Implants Res 1993;4:151–157. 97. Cosyn J, Sabzevar MM, De Bruyn H. Predictors of inter-proximal and midfacial recession following single implant treatment in the anterior maxilla: A multivariate analysis. J Clin Periodontol 2012;39: 895–903. 98. Tarnow DP, Cho SC, Wallace S. The effect of inter-implant distance on the height of the inter-implant bone crest. J Periodontol 2000;71:546–549. 99. Nevins M, Chu SJ, Jang W, Kim DM. Evaluation of an innovative hybrid macrogeometry dental implant in immediate extraction sockets: A histomorphometric pilot study in foxhound dog. Int J Periodontics Restorative Dent 2019;39:29–37. 100. Chu SJ, Ostman PO, Nicolopoulos C, et al. Prospective multicenter clinical cohort study of a novel macro hybrid implant in maxillary anterior postextraction sockets: 1-year results. Int J Periodontics Restorative Dent 2018;38(suppl):S17–S27.

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79. Lazzara RJ, Porter SS. Platform switching: A new concept in implant dentistry for controlling post-restorative crestal bone levels. Int J Periodontics Restorative Dent 2006;26:9–17. 80. Canullo L, Fedele GR, Iannello G, Jepsen S. Platform switching and marginal bone-level alterations: The results of a randomized controlled trial. Clin Oral Implants Res 2010;21:115–121. 81. Linkevicius T, Apse P, Grybauskas S, Puisys A. Influence of thin mucosal tissues on crestal bone stability around implants with platform switching: A 1year pilot study. J Oral Maxillofac Surg 2010;68: 2272–2277. 82. Vervaeke S, Dierens M, Besseler J, De Bruyn H. The influence of initial soft tissue thickness on peri-implant bone remodeling. Clin Implant Dent Relat Res 2014;16:238–247. 83. Puisys A, Linkevicius T. The influence of mucosal tissue thickening on crestal bone stability around bone-level implants. A prospective controlled clinical trial. Clin Oral Implants Res 2015;26:123–129. 84. Linkevicius T, Puisys A, Steigmann M, Vindasiute E, Linkeviciene K. Influence of vertical soft tissue thickness on crestal bone changes around implants with platform switching: A comparative clinical study. Clin Implant Dent Relat Res 2015;17:1228–1236. 85. Rodriguez X, Acedo AN, Vela X, Fortuno A, Garcia JJ, Nevins M. Arrangement of peri-implant connective tissue fibers around platform-switching implants with conical abutments and its relationship to the underlying bone: A human histologic study. Int J Periodontics Restorative Dent 2016;36:533–540. 86. Rodriguez-Ciurana X, Vela-Nebot X, Segala-Torres M, Rodado-Alonso C, Cambra-Sanchez J, Tarnow DP. The effect of inter-implant distance on the height of the inter-implant bone crest when using platform-switched implants. Int J Periodontics Restorative Dent 2009;29:141–151. 87. Elian N, Bloom M, Dard M, Cho SC, Trushkowsky RD, Tarnow DP. Effect of interimplant distance (2 and 3 mm) on the height of interimplant bone crest: A histomorphometric evaluation. J Periodontol 2011;82: 1749–1756. 88. Degidi M, Nardi D, Piattelli A. One abutment at one time: Non-removal of an immediate abutment and its effect on bone healing around subcrestal tapered implants. Clin Oral Implants Res 2011;22:1303–1307.

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IN THIS CHAPTER: • Implants Placed Immediately into Type 2 Extraction Sockets • Delayed Implant Placement • Flap Design for Delayed Implant Placement After Ridge Healing

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Chapter 3

Management of Type 2 Extraction Sockets Guido O. Sarnachiaro, dds / Stephen J. Chu, dmd, msd, cdt / Dennis P. Tarnow, dds 77

T

ype 2 extraction sockets, previously described in chapter 1, present a different set of challenges to the clinician where the soft tissue is intact, yet the labial bone plate is partially or completely absent, defined as a dentoalveolar dehiscence defect. The diagnosis of this socket type is most critical prior to treatment. Clinical sounding in conjunction with CBCT sectional radiographs is extremely helpful for diagnosis. The greatest danger in the treatment of type 2 extraction sockets is esthetic in nature, recession being the risk.

Implants Placed Immediately into Type 2 Extraction Sockets The placement of implants into type 2 extraction sockets has been documented in the dental literature since Gelb published a 4-year retrospective analysis on implant survival in 1993,1 reporting a 98% survival rate. Subsequently, other authors have not only placed implants into extraction sockets with dehiscence defects but also included provisional restoration of these implants.2–6 The main concern with type 2 extraction sockets is not so much implant

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survival but esthetic outcome, because the lack of a labial bone plate increases the risk of midfacial recession. Kan et al categorized dentoalveolar defects into various shapes—V (narrow), U (wide), and UU (ultrawide)—that denoted the width of the dehiscence lesion and the associated percentage of risk for recession.7 They found that the greater the defect in width, the greater risk of recession, increasing from 8% (V-shaped) to 100% (UU-shaped). Chu et al further subclassified type 2 sockets according to the length of the dehiscence defect following tooth removal8: • Type 2a: Coronal third of the socket involved (Figs 1 and 2) • Type 2b: Coronal and middle thirds of the socket involved (Figs 3 and 4) • Type 2c: Apical third of the socket involved or complete dehiscence of the labial bone plate (Figs 5 and 6) Therefore, the greatest risk would be posed by a type 2c-UU socket that is both long and wide. Together, these potential risk factors must be considered and weighed prior to immediate implant placement into type 2 sockets. Type 2a-V and 2b-V sockets are quite amenable to immediate tooth replacement therapy.

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TYPE 2a

Figs 1 and 2 Type 2a socket. Only the coronal third of the socket is involved.

78 Chapter 3: Management of Type 2 Extraction Sockets

1

2

TYPE 2b

Figs 3 and 4 Type 2b socket. The coronal and middle thirds of the socket are involved.

3

4

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TYPE 2c

Originally published in: Chu SJ, Sarnachiaro GO, Hochman MN, Tarnow DP. Subclassification and clinical management of extraction sockets with labial dentoalveolar dehiscence defects. Compendium 2015;36(7):516–522. Copyright ©2015 to AEGIS Publications, LLC. All rights reserved. Used with permission of the publishers.

Figs 5 and 6 Type 2c socket. Note the complete dehiscence of the labial bone plate.

79

5

The treatment protocol was outlined by Sarnachiaro et al in 2016.5 It entails the following clinical steps for consistent outcomes: 1. Atraumatic tooth extraction without tearing of the peri-implant soft tissues. 2. Implant placement with primary implant stability > 30 Ncm (Fig 7). Implant placement should be aimed toward the cingulum of anterior teeth or into the palatal root socket for premolars but exiting from the central fossa. 3. Fabrication of a custom healing abutment (anterior or posterior site) or provisional restoration not in occlusion (anterior site) (Fig 8).

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4. Placement of a cross-linked collagen membrane that maintains its rigidity in the presence of blood between the residual socket wall and the implant surface to the height of the free gingival margin. Essentially, this transforms a type 2 socket into a type 1 scenario (Fig 9). 5. Placement of a bone graft between the collagen membrane and the implant surface like a type 1 socket (Fig 10). 6. Replacement of the custom healing abutment (Fig 11) or provisional restoration (Fig 12) to seal and protect the bone graft during the 6-month healing phase and to maintain the shape of the socket.9

Implants Placed Immediately into Type 2 Extraction Sockets

6

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Figs 7 to 11 Protocol for immediate tooth replacement therapy in type 2 sockets.

Fig 7 Implant placement.

Fig 8 Fabrication of a custom healing abutment or provisional restoration.

Fig 9 Placement of a crosslinked collagen membrane.

Fig 10 Placement of a bone graft.

Fig 11 Replacement of the healing abutment.

Fig 12 Placement of the provisional restoration.

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Fig 13 Buccal plate thickness (mm) as measured by CBCT (N = 10). (Data from Sarnachiaro et al.5)

4.0 3.6

3.0

3.0

2.0 1.0 0.0 –1.0

–0.6

Pre-CBCT

Post-CBCT

6–8 months

Net change

81 Implants Placed Immediately into Type 2 Extraction Sockets

In a CBCT study on maxillary first and second premolars employing this clinical technique, the aforementioned authors were able to construct 3.6 mm of buccal plate where no plate existed prior to treatment. A healing time of 6 to 8 months was allowed for new bone maturation and mineralization before impression making. At delivery of the definitive restoration, CBCT analysis revealed a net bone gain of 3.0 mm; therefore, the amount of bone graft material remodeling was 0.6 mm (Fig 13). Spray et al10 and Chappuis et al11 have shown a gain of 2+ mm to be stable over time. It is paramount to understand that graft materials only provide support for ridge contour, shape, and volume; they do not alter the cell type that will occupy the implant surface.12

0

14

Clinical example A patient presented with a buccal fistula 3 mm above the free gingival margin of a maxillary right second premolar (Fig 14). Radiographic evaluation showed that endodontic treatment was performed, but there were no signs of periapical pathology. However, CBCT showed evidence of a partial loss of the buccal bone plate, and upon clinical examination, the buccal probing was 9.0 mm deep and narrow, indicative of a type 2b-V socket (Fig 15). The metal-ceramic crown was removed, and a buccopalatal fracture was noted. Flapless extraction of the diseased tooth root and thorough socket debridement were performed (Fig 16). A Nabers probe was used to confirm the perforation of the buccal mucosa caused by the drainage point, and a threaded

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15

16

tapered implant was placed with 60-Ncm implant torque. Immediately after implant placement, a customized healing abutment was fabricated based on the size and shape of the tooth extracted using a preformed shell (iShell, BioHorizons/Vulcan Custom Dental). Once this clinical step was complete, the

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COLLAGEN MEMBRANE PLACEMENT

82 18

Chapter 3: Management of Type 2 Extraction Sockets

17

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19

customized healing abutment was removed, polished, and steam cleaned. A narrow, standard 5.0-mm-tall healing abutment was placed prior to membrane placement and hard tissue grafting of the buccal gap. Considering there was a partial dehiscence of the buccal bone, a cross-linked collagen membrane was placed inside the socket against the buccal mucosa to the height of the free gingival margin (Fig 17). Small-particle (250–500 µm) mineralized cancellous bone allograft material was used to fill the gap between the implant and the collagen membrane (Fig 18). Once this process was accomplished, the standard healing abutment

was removed, and the customized healing abutment was screwed back, serving both to protect the socket shape and to contain the material. An immediate postoperative CBCT was taken, showing the presence of the bone graft material buccal to the implant (Fig 19). The beauty behind this technique is that the anatomical contour of the tissues can be preserved from the moment the extraction takes place, rather than having to regenerate it 4 to 6 months later, with all the challenges and extra visits that it presents. After 8 months of healing, there was no recession, and the customized healing abutment

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8 MONTHS

20

21

83 Implants Placed Immediately into Type 2 Extraction Sockets

23

22

24

3 YEARS

25

26

was removed for final impression making (Figs 20 and 21). An 8-month postoperative CBCT was taken to confirm the presence of regenerated bone in the buccal area of the implant (Fig 22). The final impression was made, and a

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27

screw-retained metal-ceramic definitive restoration was fabricated (Figs 23 and 24). Figures 25 to 27 demonstrate the 3-year posttreatment recall clinical photograph, buccal-occlusal view, and CBCT showing a stable bone plate.

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Delayed Implant Placement Delayed implant placement is indicated when the patient presents with a type 2c-UU lesion; in this circumstance, immediate implant placement would be risky and questionable at best. In these situations, socket preservation is a very good treatment strategy that can yield predictable results.

Membranes for socket preservation

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There are two basic categories of membranes that are used in dentistry: absorbable and nonabsorbable. Presently, their use before or at the time of implant placement is very common, especially when additional bone is required.

Nonabsorbable membranes Nonabsorbable membranes were some of the first used both in the treatment of periodontal defects on teeth as well as for ridge augmentation for either cosmetic or implant reasons. The pros of using this material are that it will not resorb and will stay in the mouth for as long as the clinician feels is required. It is usually made of expanded polytetrafluoroethylene (PTFE), either in a dense or stretched form. It can be secured in place and constructed with an internal titanium framework to maintain the desired shape and space for bone graft materials. Therefore, this is a very effective method for guided bone regeneration (GBR). However, there are drawbacks to the use of this membrane. The most common drawback is that the soft tissue can dehisce and expose the membrane during the healing phase of therapy. This can require removal prior to the intended time, which has been shown to interfere with the amount of bone development. Nonabsorbable membranes also must be removed after bone maturation, requiring an extra surgical procedure. While these membranes are suitable for cases in which implants are placed after GBR procedures, they may not be appropriate for esthetic ridge augmentation due to the loss of ridge volume after their removal.

Absorbable membranes Absorbable membranes are some of the most commonly used in implant dentistry and periodontology today. This is mainly because they do not need to be surgically removed. Plus, if they become exposed to the oral cavity, they will quickly be absorbed within a few weeks’ time by the salivary enzymes. While this can certainly be considered an advantage, they may in fact resorb too quickly for certain types of defects, particularly larger bone augmentation procedures that require extra maturation time for bone fill under the membrane. There is also great variation in how long each of these membranes will stay intact, even if they stay covered. In other words, the thickness of the membrane, the type of collagen used, and how it is processed (ie, higher degree of cross-linking will slow its absorption time) will determine how long the membrane will stay intact. Obviously, if a large graft is being placed, then a thicker, more cross-linked collagen membrane should be used. Each company has information on the absorption rate of their membranes. The main disadvantage of some of these collagen membranes is that they are not usually very effective in space maintenance. Therefore, for larger defects, the clinician may have to use graft materials such as a xenograft or large-particle mineralized cortical bone, which are not prone to resorbing, instead of small-particle allograft or demineralized bone that can collapse as it is replaced under the membrane. In addition, clinicians must sometimes insert bone screws into the ridge that protrude or “tent” far enough to prevent the collapse of the membrane during the healing phase. In addition, not all of these membranes can be sutured or tacked into place. Some collapse and drape over the graft when wet, while others are more rigid and hold their form even after moisture and/or heme saturation. For the ice cream cone technique, or the previously described management of immediate implant placement in type 2 defects, one should use a more rigid (cross-linked) form of these collagen membranes that can be placed into the socket without collapsing and sutured.

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Fig 28 Type 2 socket with intact soft tissue but a midfacial osseous dehiscence defect.

Reconstruction and rehabilitation of oral anatomical defects require meticulous analysis. The long-term maintenance should be the main goal, utilizing simple, available, predictable, and affordable technologies. The ideal technique for restoring the buccal plate of bone after tooth extraction should not only be simple but also minimally invasive while preserving the attached gingiva and soft tissue contours. Such a socket repair procedure, commonly known as the ice cream cone technique and described by Elian et al in 2007,13 was created for the treatment of type 2 sockets, where the facial soft tissue is present in its ideal height and shape but there is a midfacial osseous dehiscence defect following tooth extraction (Fig 28). Once a tooth is deemed hopeless and the extraction is indicated, the surgical procedure is performed with an atraumatic approach. Following an incision of the supracrestal fibers, the tooth extraction is performed without elevating a mucoperiosteal flap (Fig 29).

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Delicate elevators and small beak forceps should be used. The main focus for the implant surgeon at this point should be preservation of the alveolar bone. The use of fine diamond burs to section the roots is also recommended in more challenging extraction situations. Once the tooth is extracted, the socket is thoroughly debrided and irrigated with saline solution (sodium chloride in water) to ensure proper decontamination and removal of all infected tissue. It is imperative that perforation of the soft tissue during debridement is avoided (Fig 30). It is common for the peri-implant soft tissues to become flaccid and collapse because there is a lack of osseous architecture and support (see Fig 38). An absorbable cross-linked collagen membrane is contoured into a modified V-shape or ice cream cone shape (Fig 31). The membrane should be resistant to tearing and rigid so that it can be sutured and maintain a long absorption time to allow for GBR. The membrane must also be firm enough to allow insertion into the socket without collapsing. The narrow part of the trimmed membrane (ie, the V-shaped cone)

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Ice cream cone technique

Fig 29 Atraumatic tooth extraction without flap elevation.

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Fig 30 Socket after tooth extraction and debridement.

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Fig 31 Collagen membrane contoured into a modified V or ice cream cone shape.

is placed into the socket and should be wide enough to extend laterally past the defect in the buccal wall. The wider part of the membrane should be trimmed to cover the opening of the socket following graft placement (Fig 32). Following final shaping, the membrane is positioned into the socket lining the buccal tissues. The socket is then filled with a bone graft material; pressure from the graft against

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Fig 32 Placement of the ice cream cone collagen membrane.

the membrane will help keep it in place and stable while extending the contour of the buccal soft tissues. Ideally, the graft material should be compressed into the socket and remain in place (Fig 33). The graft material recommended for this technique is a small-particle (250–500 µm), mineralized cancellous freeze-dried bone allograft. The graft material should be hydrated

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Fig 33 Socket filled with graft material.

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Fig 34 The membrane is extended over the socket and sutured.

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Figs 35 and 36 Socket after absorption of the collagen membrane and graft incorporation.

for 5 minutes and retain enough moisture for the particles to aggregate when inserted. This allograft material compresses well and, because it is mineralized, slowly resorbs. It also helps to keep the shape of the socket while new bone repopulates and fills the socket during healing. After the graft is compressed, the canopy part of the membrane is extended over the opening of the socket. The membrane is then sutured with two or three 5-0 absorbable sutures to the palatal tissue (Fig 34). No sutures are needed on the buccal aspect because the membrane

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is kept in place from the pressure of the graft against the buccal tissue. The ice cream cone technique allows for the reconstruction of a buccal plate dehiscence to enable the placement of an implant (Figs 35 and 36). While a recent study by Tan et al showed ridge dimension changes amounting to a diminished width of 1.32 mm after healing compared with the preextraction socket,14 this does not preclude subsequent palatal implant placement after healing with supplemental grafting, if needed (see Fig 43).

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Clinical example Figures 37 to 43 illustrate this protocol in a clinical case. Note the flaccid peri-implant soft tissues after tooth extraction resulting from lack of osseous support.

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Delayed implant placement with immediate provisional restoration With delayed implant placement, once the ridge is healed or reconstructed, implants can be placed. Buser suggests waiting 6 to 8 weeks before placing an implant and grafting the facial bone to allow for new bone growth to help stabilize the implant. The question becomes whether to place just a healing abutment or a provisional restoration. With delayed sites, higher insertion torque values should be expected because the implant is engaging much more bone after the osteotomy is made compared with an extraction socket, and consequently that should equate to greater stability. With immediate implant placement, the implant

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Flap Design for Delayed Implant Placement After Ridge Healing This section outlines two different methods of implant placement—a punch technique and a flap technique—and explains how to fabricate

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and contour the provisional restoration with each. There exists a balance between the surgical and prosthetic challenges of these two techniques.

Punch technique With the punch technique, flap elevation is averted, so the site is not compromised at all. Note that there must be adequate bone and attached gingiva present. Consequently, implant placement becomes more challenging because it is performed blind. With this technique, the site should be developed prior to implant placement because without a flap, site augmentation is not possible. However, fabrication of the provisional restoration is much easier because the soft tissues can be shaped and sculpted nonsurgically simultaneously with implant placement through contour and soft tissue pressure from the provisional restoration.16,17

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does not obliterate the socket, and therefore only the more apical portion of the implant engages bone. While sometimes that allows enough torque (30 to 40 Ncm) to place a provisional restoration, delayed sites may offer much better initial stability for provisional restoration because the whole body of the implant is in contact with bone. A 2011 study published in Europe investigated the survival rates of delayed implants to see the difference between placing an immediate provisional restoration versus just a healing abutment.15 The test group, which included implants with provisional restoration, had a slightly lower survival rate (97%) than the control group (just a healing abutment, 100%). Interestingly, however, the survival rates in both groups are equivalent to the overall data for immediate implants in extraction sites. One of the key strategies for success is keeping the provisional restoration out of occlusion to protect the implant. Functional overload while the bone is trying to heal is a not a positive situation and should be avoided.

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Clinical example A patient presented with a primary canine in the maxillary right quadrant; the permanent tooth was impacted (Figs 44 and 45). While this common situation is easily treated in the adolescent during growth and development, there are fewer options available for an adult who is unwilling to undergo 5 years of orthodontic therapy. Consequently, the primary tooth and the impacted permanent tooth were extracted, and the site was augmented and prepared for implant placement 6 months later (Figs 46 and 47). After healing, the width of the ridge was sufficiently

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thick for implant placement, and there was at least 4 to 5 mm of vertical soft tissue height and width due to the previous site development, so a transmucosal punch was performed with a surgical punch (Figs 48 to 51). Because the site was previously augmented, the surgeon was confident that there was sufficient bone to place the implant flapless and preclude any fenestrations based on CT scan views (Figs 52 and 53). The provisional restoration was then fabricated and restored without occlusal contact (Figs 54 to 58). The benefit behind this technique is that the tissues can be sculpted immediately after implant placement. Because the contour of the restoration depends on the spatial implant position and thickness of the soft tissues, acrylic or flowable composite can be added to achieve the proper contour. Once the provisional restoration has been placed and

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the site has healed, no further soft tissue sculpting is required after the initial phase of bone healing (8–12 weeks) because it was performed at the time of implant placement.

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After 4 months of healing, there was no recession, and the final impression was made (Figs 59 and 60). A screw-retained metalceramic definitive restoration was fabricated with acceptable color matching (Figs 61 to 63).

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While this technique requires more preliminary treatment, it can also result in an esthetic and functional outcome and is a good treatment strategy for single anterior tooth replacement.

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Clinical example A patient presented with a fractured maxillary right lateral incisor (Fig 64). The tooth was removed, and a delayed approach using the ice cream cone technique was used to place an implant because the socket was not intact (type 2b-V) (Figs 65 to 67). While some socket repair was performed at the time of extraction, further augmentation was still required at the time of implant placement due to a labial concavity associated with the fractured tooth (Fig 68). The papilla-sparing procedure was used to preserve the interproximal papilla, and

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The flap technique offers distinct advantages but also has some drawbacks. Visualization of the implant placement is definitely enhanced because the surgeon can see the bony architecture under the flap. A papilla-sparing incision design can be used to minimize the amount of recession of the interdental papilla.18 This technique allows simultaneous ridge augmentation to be performed in conjunction with implant placement. The disadvantage is that provisional restoration fabrication tends to be more challenging because it requires very flat or even concave subgingival contours to allow proper flap adaptation. Excessive subgingival contour with the flap technique can spell problems, namely poor flap adaptation, potential loss of the flap, and/or recession.

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the flap was extended to gain more access to the site (Figs 69 and 70). The broad base not only allowed access but also enhanced blood supply to the flap. The ridge had somewhat collapsed, which allowed palatal access and therefore a more palatal approach for implant placement, which facilitated use of a screwretained provisional restoration (Figs 71 and 72). In situations like these with palatal bone present, a bone graft can be used on the labial aspect to augment the site.

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Because the implant was replacing a lateral incisor, a narrow implant was used. These smaller-diameter implants tend to be used when the distance between adjacent teeth is 5 mm mesial to distal and 6 mm buccal to lingual. In this case, the buccolingual dimension needed to be enhanced, and the palatal access allowed placement of a bone graft. Before the graft was placed, the provisional restoration was fabricated while there was access to the site (Fig 73). The beauty behind

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the flapped technique is that it can ensure that the access hole of the provisional restoration is exiting the cingulum. Placing it in this manner facilitates creation of a screw-retained restoration (Fig 74). Screw-retained provisional restorations such as a UCLA crown have the distinct advantage that they have only one subgingival interface (the abutment-implant interface), which is a more advantageous prosthetic design because there is only one area with the potential for micromovement or microleakage. Cement-retained provisional restorations have two interfaces—the abutment-implant interface and the crown-abutment interface—as well as the potential for residual cement in the peri-implant sulcus. When joining the tooth portion of the provisional restoration to the temporary cylinder that is screw-retained, the key element is an extremely flat subgingival contour, almost the same profile as the cylinder itself. The issue here is trying to negotiate flap adaptation around the provisional restoration. With excessive subgingival contour, it is likely that the flap will not adapt properly to the restoration, which increases the risk for recession or loss of the flap, exposure of the graft, and potential infection of the graft, so there could be huge negative consequences in regard to an improperly contoured provisional restoration. One may have to use a straight healing abutment instead of the provisional crown with the papilla-sparing technique. This is to allow the vertical incisions to be closed well. A provisional restoration sometimes will push the buccal flap too far out, resulting in poor closure. These cases will then have to be sculpted and contoured with pressure after the vertical incisions heal in about 4 weeks. Also, if a cement-retained restoration has to be used, the clinician should make sure that a custom abutment is used to festoon the margin and to prevent the cement margin from being too deep below the tissue, which will happen if a standard abutment is used.

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Before the graft was placed, an appropriately sized absorbable membrane was selected and shaped so that it would fit properly over the graft (Fig 75). The bone graft was then placed and packed into position (Figs 76 and 77). Because the membrane was already trimmed to the proper size, the bone graft particles were completely covered and would not be dislodged (Fig 78). After suturing, flap adaptation without any tension was achieved due to the subgingival flat or concave contour of the provisional restoration (Fig 79). The patient left the office with the implant in place, the labial aspect augmented, and the provisional restoration seated out of occlusion.

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After 1 week, the site was healing quite well (Fig 80). After 5 months, the provisional restoration was removed for final impression making. An implant-level impression was made using acrylic Pattern Resin (GC America; Fig 81). This has to be performed quickly because the soft tissues tend to collapse immediately after provisional restoration removal. The impression was then sent to the laboratory for fabrication of the definitive restoration, a screw-retained metal-ceramic crown. This simple technique resulted in an esthetic outcome (Figs 82 and 83).

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Portions of this section and figures republished with permission, Journal of Cosmetic Dentistry, ©2019 American Academy of Cosmetic Dentistry, All Rights Reserved. 608.222.8583; www.aacd.com. 83

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Soft tissue sculpting with the provisional restoration It is preferable to sculpt the soft tissues after implant healing and integration; however, it is important to give the soft tissues enough time to mature as they are being stretched and conditioned. Alternatively, rather than sculpting the tissue in one patient visit, it can be accomplished gradually over a series of appointments at 1- to 2-week intervals. For the patient in Fig 84, soft tissue sculpting in one appointment led to ischemic necrosis after 1 week without significant consequences in the end result. This

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is why care must be taken when sculpting the tissue. While some blanching is expected, if the ischemia does not go away after 10 or 15 minutes, then there is too much soft tissue pressure, which will necrose the tissue (Figs 85 and 86). If the blanching persists beyond 15 minutes, the provisional crown should be removed, reshaped, and undercontoured before it is replaced. Again, the ischemia should dissipate after 10 to 15 minutes. In this patient, the tissue started to mature after 1 month (Fig 87). After 3 months, an implant-level impression was made, and the definitive restoration was properly contoured (Figs 88 and 89).

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References

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99 References

1. Gelb DA. Immediate implant surgery: Three-year retrospective evaluation of 50 consecutive cases. Int J Oral Maxillofac Implants 1993;8:388–399. 2. Noelken R, Kunkel M, Wagner W. Immediate implant placement and provisional restoration after long-axis root fracture and complete loss of the facial bony lamella. Int J Periodontics Restorative Dent 2011;31:175–183. 3. da Rosa JC, Rosa AC, da Rosa DM, Zardo CM. Immediate dentoalveolar restoration of compromised sockets: A novel technique. Eur J Esthet Dent 2013;8:432–443. 4. da Rosa JC, Rosa AC, Francischone CE, Sotto-Major BS. Esthetic outcomes and tissue stability of implant placement into compromised sockets following immediate dentoalveolar restoration: Results of a prospective case series at 58 months follow-up. Int J Periodontics Restorative Dent 2014;34:199–208. 5. Sarnachiaro GO, Chu SJ, Sarnachiaro E, Gotta SL, Tarnow DP. Immediate implant placement into extraction sockets with labial plate dehiscence defects: A clinical case series. Clin Implant Dent Relat Res 2016;18:821–829. 6. Tripodakis AP, Gousias H, Mastoris M, Likouresis D. Five-year volumetric evaluation of periodontally compromised sites restored by immediate implant restorations. Int J Periodontics Restorative Dent 2016;36:645–653. 7. Kan JY, Rungcharassaeng K, Sclar A, Lozada JL. Effects of the facial osseous defect morphology on gingival dynamics after immediate tooth replacement and guided bone regeneration: 1-year results. J Oral Maxillofac Surg 2007;65:13–19. 8. Chu SJ, Sarnachiaro GO, Hochman MH, Tarnow DP. Subclassification and clinical management of extraction sockets with labial dentoalveolar dehiscence defects. Compendium 2015;36:516–525.

9. Crespi R, Capparé P, Crespi G, Gastaldi G, Romanos G, Gherlone E. Tissue remodeling in immediate versus delayed prosthetic restoration in fresh socket implants in the esthetic zone: Four-year follow-up. Int J Periodontics Restorative Dent 2018;38(suppl): s97–s103. 10. Spray JR, Black CG, Morris HF, Ochi S. The influence of bone thickness on facial marginal bone response: Stage 1 placement through stage 2 uncovering. Ann Periodontol 2000;5:119–128. 11. Chappuis V, Rahman L, Buser R, Janner S, Belser U, Buser D. Effectiveness of contour augmentation with guided bone regeneration: 10-year results. J Dent Res 2018;97:266–274. 12. Rosenlicht JL, Tarnow DP. Human histologic evidence of integration of functionally loaded hydroxyapatite-coated implants placed simultaneously with sinus augmentation: A case report 2.5 years post placement. J Oral Implantol 1999;25:7–10. 13. Elian N, Cho SC, Froum S, Smith RB, Tarnow DP. A simplified socket classification and repair technique. Pract Proced Aesthet Dent 2007;19:99–104. 14. Tan-Chu JHP, Tuminelli FJ, Kurtz KS, Tarnow DP. Analysis of buccolingual dimensional chnages of the extraction socket using the ‘ice cream cone’ flapless grafting technique. Int J Periodontics Restorative Dent 2014;34:399–403. 15. den Hartog L, Raghoebar GM, Stellingsma K, Vissink A, Meijer HJA. Immediate nonocclusal loading of single implants in the aesthetic zone: A randomized clinical trial. J Clin Periodontol 2011;38:186–194. 16. Cooper LF, Reside G, Raes F, et al. Immediate provisionalization of dental implants in grafted alveolar ridges in the esthetic zone: A 5-year evaluation. Int J Periodontics Restorative Dent 2014;34:477–486. 17. Chu SJ, Tarnow DP. Provisional restoration of single tooth implants into healed ridges in the esthetic zone. J Cosmet Dent 2014;29:112–123. 18. Gomez-Roman G. Influence of flap design on peri-implant interproximal crestal bone loss around single-tooth implants. Int J Oral Maxillofac Implants 2001;16:61–67.

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IN THIS CHAPTER: • Treatment of 3 mm of Midfacial Recession • Treatment of 1 mm of Midfacial Recession with Absence of Labial Bone Plate

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ype 3 extraction sockets pose a different challenge for the clinician because they already present with midfacial gingival recession indicative of facial hard and soft tissue loss. Gingival recession and loss of periodontal attachment are often associated with periodontal disease. However, isolated areas of midfacial recession have been related to (1) cervical abrasion, erosion, or abfraction; (2) tooth malposition, specifically labioversion; (3) overcontour of a restoration; and (4) a thin periodontal phenotype.1,2 In cases of advanced midfacial recession (≥ 3 mm) due to prominent root anatomy and cervical abrasion, it is best to delay implant placement. In such cases, the tooth should be removed, and the socket should be allowed to heal with bone and soft tissue coverage naturally so that the mucogingival junction (MGJ) is left intact and in the same position (Figs 1 to 4). The tissue will fill to the height of the palatal tissue with keratizined tissue (mother nature’s connective tissue

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graft). Early delayed implant placement can be employed in these situations. Conversely, trying to cover the defect or socket at the time of tooth removal with a coronally repositioned flap will alter the location of the MGJ to an unfavorable position that will require surgical correction at a later time (Figs 5 and 6). Excessive labial tooth position is another frequent cause of midfacial recession and can be addressed by altering tooth position through orthodontic therapy. However, if a tooth presents with minimal midfacial recession (< 3 mm) and requires removal, and the midfacial tissue does not show when the patient smiles, then immediate tooth replacement therapy can be a viable treatment option. This treatment strategy includes (1) palatal implant positioning and (2) proper restorative contour to manage the midfacial recession defect, thereby allowing the gingival tissues to heal in a more coronal position.3,4

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Fig 5 The normal MGJ relationship after tooth extraction and implant placement.

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Fig 6 The MGJ will be negatively altered in a more coronal position if a flap is raised to cover an implant in an extraction socket. The zone of keratinized attached gingiva will be diminished, and an additional surgical procedure will be required to replace the MGJ back to its original location and increase the zone of attached gingiva around the implant.

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Treatment of 3 mm of Midfacial Recession A 26-year-old woman presented with existing veneer restorations on the maxillary anterior incisors with the right central incisor in a more apical position relative to the adjacent dentition (Figs 7 to 11). Even though the patient possessed a low midfacial smile line, she was aware and concerned

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about the incisal edge discrepancy as well as the negative gingival architecture due to tooth malposition in both the vertical and buccolingual directions (see Fig 7). Her prior dental history included the use of orthodontic treatment to reposition the right central incisor into the dental arch; however, this treatment was to no avail because the tooth may have been ankylosed from trauma. Radiographic examination of this tooth revealed internal root resorption (see Fig 10).

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Great care and effort were taken to remove the tooth in a minimally invasive, atraumatic flapless manner (Figs 12 and 13). The resorption lesion was evident on the palatal aspect

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of the tooth upon its removal (Fig 14). The implant was placed to a vertical depth relative to the midfacial crest of bone, roughly 3 mm from the free gingival margin (Figs 15 and 16).

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In addition, the implant was placed in a palatal position where the original tooth should have been in order to manage the proper restorative contour of the provisional restoration. A diagnostic key in the predictable treatment of type 3 recession defects is the height of the palatal tissues, which are in a coronal position and consistent with the adjacent interdental tissues (see Fig 13). An acrylic gingival sleeve or shell was fabricated and milled from a prefabricated polymethyl methacrylate block using a CAD/ CAM digital file5 (Figs 17 to 20). This sleeve was then luted to a prefabricated implant abutment post using an autopolymerizing acrylic resin (Super-T, American Consolidated) to create a screw-retained provisional restoration (Figs 21 and 22).

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Proper contour and spatial gingival undercontour were created in the provisional restoration to encourage and allow the faciogingival margin to migrate more incisal. After fabrication of the provisional restoration and its removal, a tall flat-contoured titanium healing abutment was connected to the implant to allow a small-particle mineralized cancellous bone allograft material (Puros, Zimmer Biomet) to be placed into the facial gap. This dual-zone therapeutic concept was used to graft not only the bone zone (palatal to the labial bone plate) but also the soft tissue zone (peri-implant soft tissues; Fig 23). After removal of

the titanium healing abutment, the nonocclusally loaded provisional crown restoration was replaced to contain and protect the graft material during the 4- to 6-month healing phase of treatment (Fig 24). The restorative contour of the provisional restoration was significantly undercontoured relative to the original malposition of the tooth prior to extraction. This allowed the gingival tissues to migrate more palatal and incisal to re-establish the correct midfacial free gingival margin location. Figures 25 to 28 show the tissues after 1 week to 5 months of healing and tissue maturation; note the migration of the free gingival margin coronally over this healing period. Tissue maturation is underestimated in the overall process toward esthetic success of implants placed into anterior extraction sockets. Hard tissues require 6 months and soft tissues 3 months for maturation. The provisional restoration was first disconnected from the implant following 5 months of healing (Fig 29). An implant-level impression coping was seated onto the implant, and a colored resin (Pattern Resin, GC America) was used to capture the soft tissue submergence profile (Fig 30). A polyvinyl siloxane (PVS) material (Flexitime, Kulzer) was used to transfer the spatial location of the implant (Fig 31). An implant replica or analog was placed onto the implantlevel impression coping, and a gypsum soft tissue hybrid master cast was created to allow laboratory fabrication of a screw-retained definitive restoration (Figs 32 and 33).

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Metal-ceramic was selected as the material of choice for the definitive restoration because of its optimal strength and esthetics.6 This material allowed proper subgingival contouring while maintaining maximal strength of the restoration with a platform-switched design. Gold-plating the noble metal alloy also enhanced the esthetic outcome in respect to gingival color tone7 (Figs 34 to 36). The definitive screw-retained restoration was inserted with the manufacturerrecommended screw torque (Fig 37). As shown in the 3-year posttreatment view, the tissue contour and gingival tone of the implant restoration of the right central incisor integrate well with the adjacent teeth (Fig 38). The 3-year posttreatment periapical radiograph reveals positive bone levels (Fig 39).

Originally published in: Tarnow DP, Chu SJ. Clinical management of type 3 recession defects with immediate implant and provisional restoration therapy: A case report. Compendium 2017;38(7):468–473. Copyright © 2017 to AEGIS Publications, LLC. All rights reserved. Used with permission of the publishers.

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Treatment of 1 mm of Midfacial Recession with Absence of Labial Bone Plate When the labial bone plate is absent as seen on CBCT and periapical radiographs and there is midfacial recession of 1 to 2 mm, crown contouring and type 2 socket repair (see chapter 3) should be performed to treat these defects (Figs

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40 to 42). Following removal of the clinical crown, the remaining root tip is carefully removed (as per the technique described in chapter 2) using sharp dissection and periodontal elevators (Fig 43). The soft tissues are kept intact, revealing the absence of the labial bone plate (Figs 44 to 46). The iShell device (BioHorizons/Vulcan Custom Dental; see chapter 2) is then used to restore the socket shape and subgingival contour to the preextraction situation and then joined to the implant PEEK (polyetheretherketone)

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temporary cylinder with acrylic resin (Figs 47 to 49). An acrylic veneer facing is joined to the PEEK temporary cylinder and extrinsically characterized with unfilled colored resin to create the provisional clinical crown, which is then relined slightly to the facial to be void of occlusal contact (Figs 50 and 51). Care must be taken in cases of preexisting gingival

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recession to intentionally undercontour the midfacial aspect of the provisional crown at and below the cementoenamel junction (CEJ) (see Fig 51). At this point, the esthetics and occlusion of the provisional crown are evaluated (Figs 52 and 53).

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Subsequently, the provisional restoration is removed and replaced with a flat-contour healing abutment; a cross-linked collagen membrane is fitted and placed labial to the implant (Figs 54 to 57). This membrane is trimmed to the level of the midfacial free gingival margin to reconstruct

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the lost labial bone plate as described in chapter 3 (type 2 extraction sockets) (Fig 58). A smallparticle mineralized cancellous allograft is used and inserted between the implant and collagen membrane (Figs 59 and 60). The healing abutment prevents graft particles from entering

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the implant connection that would obstruct seating of the provisional restoration (Fig 61). The graft particles are allowed to clot prior to removing the flat-contour healing abutment and re-placing the provisional restoration as per the prosthetic socket seal concept described in chapter 2 (Figs 62 to 64). The site is then allowed to heal for 8 months prior to impression making and delivery of the definitive restoration (Fig 65). This treatment can be delivered in one surgical intervention (one surgery, one time), and a predictable protocol is outlined in chapter 7 (see Case 9).

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Conclusion The use of immediate implant and provisional restoration therapy in type 3 sockets (recession) can lead to predictable esthetic outcomes. The diagnostic keys for success are the following: • Preexisting labial tooth malposition with existing palatal tissue at the correct height • Flapless tooth removal • Palatal implant placement • Dual-zone socket grafting • Provisional restoration placement with nonocclusal loading • Proper tissue maturation for 4 to 6 months

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References 1. Weisgold AS. Contours of the full crown restoration. Alpha Omegan 1977;70:77–89. 2. Su H, Gonzalez-Martin O, Weisgold AS, Lee EA. Considerations of implant abutment and crown contour: Critical contour and sub-critical. Int J Periodontics Restorative Dent 2010;30:335–343. 3. Steigmann M, Monje A, Chan HL, Wang HL. Emergence profile design based on implant position in the esthetic zone. Int J Periodontics Restorative Dent 2014;34:559–563. 4. Chu SJ, Kan JYK, Lee EA, et al. Restorative emergence profile for single tooth implants in healthy periodontal patients: Clinical guidelines and decision-making strategies. Int J Periodontics Restorative Dent (in press). 5. Chu SJ, Hochman MN, Tan-Chu JH, Mieleszko AJ, Tarnow DP. A novel prosthetic device and method for guided tissue preservation of immediate postextraction socket implants. Int J Periodontics Restorative Dent 2014;34(suppl 3):S9–S17. 6. Gallucci GO, Grutter L, Nedir R, Bischof M, Belser UC. Esthetic outcomes with porcelain-fused-to-ceramic and all-ceramic single-implant crowns: A randomized clinical trial. Clin Oral Implants Res 2011;22:62–69. 7. Ishikawa-Nagai S, DaSilva JD, Weber HP, Park SE. Optical phenomenon of peri-implant soft tissue. Part II. Preferred implant neck color to improve soft tissue esthetics. Clin Oral Implants Res 2007;18:575–580.

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IN THIS CHAPTER: • Tooth Extraction for Multirooted Teeth • Implant Placement into Molar Extraction Sockets • Alternative Immediate Molar Implant Placement Strategies • Clinical Example • Delayed Protocol for Molar Teeth

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Chapter 5

Clinical Management of Posterior Teeth Richard B. Smith, dds / Dennis P. Tarnow, dds

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osterior multiroot extraction sockets, in particular molar sockets, present a set of unique clinical circumstances compared with sockets of anterior teeth. Anatomical limitations such as the maxillary sinus, the inferior alveolar nerve, inferior bone density, and large socket circumference all present significant challenges for immediate molar implant placement. Nonetheless, immediate implants can be placed routinely into molar sockets with success rates equal to those of implants placed in a delayed protocol.1–7 Besides being more efficient in terms of treatment delivery (only one surgical procedure) and reducing overall treatment time, the results can be quite predictable, yielding favorable restorative and surgical outcomes. Critical elements of successful immediate molar tooth replacement therapy are atraumatic tooth extraction without flap elevation and implant primary stability.8 An important benefit of the immediate molar implant, especially when an ultrawide implant (> 6 mm) is placed together with a customized healing abutment or provisional crown restoration, is that it provides more effective preservation of ridge dimension and soft tissue architecture9 (Figs 1 and 2). Proper implant placement with the unique restorative considerations of molar

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1

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Figs 1 and 2 An 8-mm-diameter ultrawide implant is immediately placed at the site of the mandibular right first molar. The wide prosthetic platform provides for smaller gingival embrasure spaces and a natural-appearing emergence profile of the restoration.

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Figs 3 and 4 The mandibular left first molar is hemisected into its mesial and distal roots for atraumatic root removal, preserving maximum septal bone.

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sites in mind will allow for improved clinical results. Better, more anatomically appropriate root and crown contours can be achieved, thereby eliminating or minimizing buccolingual and mesiodistal food impaction areas. From diagnosis to extraction to restoration, molar sites require attention to the details and characteristics that are inherently different from anterior, single-rooted tooth sites. 7

Tooth Extraction for Multirooted Teeth When anticipating immediate implant placement, the clinician should extract multirooted premolars and molars with minimal trauma and without flap elevation, preserving as much intraradicular bone (septum) as possible. The removal strategy is to section a multirooted tooth into its component individual roots for gentle single-root luxation, elevation, and removal. Mandibular molars may be hemisected

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6

Figs 5 to 7 The maxillary right first molar is trisected into its individual roots for atraumatic root removal, preserving maximum septal bone.

in a buccolingual direction; once the coronal portion of the tooth is reduced, the roots may be luxated and elevated, usually toward the septum, to follow the path of the curvature of the roots for gentle removal (Figs 3 and 4). Maxillary molars may be trisected, the coronal portion reduced, and the roots gently luxated and elevated, also in the path of the curvature of the individual roots to avoid root fractures (Figs 5 to 7). Most maxillary first premolars are two-rooted and are

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Fig 8 A long, thin, tapered high-speed diamond bur (Brasseler #859L) is used to create space for root elevators around sectioned roots of molars for atraumatic root removal.

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Implant Placement into Molar Extraction Sockets Implant stability is critical to the success of any immediately placed implant. In the anterior region, implant stability is usually achieved by placing the implant at least 3 mm beyond the

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apex of the socket.10 In the molar region, however, the inferior alveolar nerve in the mandible and the maxillary sinuses often preclude placement of the implant apical to the socket. Therefore, the socket morphology itself becomes critical to the placement of an immediate implant in molar sites. Previous authors have shown that initial torque values of as little as 15 Ncm yield an 86% survival rate of 6-mm-wide implants placed immediately in molar sockets.11 With ultrawide implants (7, 8, or 9 mm), higher initial torque values are routinely achieved, leading to survival rates of 96%.12 Molars are typically multirooted and, as described previously, should be resected prior to extraction in order to preserve the septal bone so it can be used for implant stabilization where appropriate. Second molars, particularly mandibular second molars, commonly have convergent roots, resulting in sockets with no septum that require wide or ultrawide implants to engage the peripheral walls for stabilization. The implant placement protocol is in large part related to socket morphology (ie, the nature of the septum and the peripheral socket walls as they relate to potential stabilization of the implant) and may be described on the basis of the Smith/Tarnow molar socket classification system.13

Implant Placement into Molar Extraction Sockets

therefore hemisected in a mesiodistal direction for removal of individual roots. In each of these procedures, careful identification of the position of the furcation(s) using a Nabers probe is critical. Once the location of the furcation is confirmed, the tip of a flameshaped high-speed diamond bur is placed in the appropriate location that will allow for accurate root resection. Radiographic confirmation of adequate and accurate resection may be advisable prior to attempting root removal. A thin, tapered, long-shank high-speed diamond bur (Fig 8) may be used judiciously to free the individual roots, creating enough space along the root surface for slender root elevator instruments. Care should be taken to avoid drilling on the buccal aspect of the roots to preserve the buccal plate intact. After root removal and prior to performing the osteotomy, it is important to thoroughly debride and irrigate the socket(s).

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TYPE A

Fig 9 Type A socket: Septum completely contains the implant (typically an implant up to 5 mm in diameter).

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TYPE B

Fig 10 Type B socket: Septum is utilized to stabilize the implant but does not fully contain it. One or more of the root socket spaces are in contact with the implant surface. The outer walls of the socket must be intact in order for full osseointegration to occur. Root sockets do not require grafting.

Type A The septum of bone is large enough to stabilize and fully surround the implant (Fig 9). Smallerdiameter implants may be required in order to remain within the bone septum (ie, 4.0, 4.6, or 5.0 mm). The septum bone begins at the base of the furcation of the tooth and is on average 3 to 4 mm from the cementoenamel junction.14 Therefore, using the top of the septum bone as the vertical positioning landmark for implant placement allows the implant to be placed on average 3 to 4 mm apical to the buccal crest of tissue, which is ideal for proper emergence contours of the implant crown.

Type B The septum is engaged and stabilizes the implant but does not fully surround it. The implant surface is exposed to one or more of the root sockets (Fig 10). It is imperative that the outer walls of the socket are intact for bone formation to occur on all implant surfaces. A gap may remain between the implant and the

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outer walls of the socket. These gaps do not require grafting for osseointegration to occur because the clot will fill this gap and, if undisturbed, bone will form against the implant just as in any other extraction socket as it heals by secondary intention.15 A standard or customized healing abutment or a nonloaded provisional restoration is placed with no graft, membrane, or soft tissue closure necessary (no flap elevation or mobilization during extraction/placement). Grafting the root socket gaps is optional and serves only to preserve ridge architecture for esthetic or patient comfort purposes.

Type C There is either an insufficient or absent septum, and implant stability is achieved by engaging the outer socket walls (Fig 11). Wider-diameter implants (ie, 6, 7, 8, or 9 mm) are necessary in these situations to engage these outer walls. Bear in mind that the buccal walls of molar extraction sockets are much thicker than those of anterior tooth sockets,16 and therefore bone resorption, tissue recession, and loss of implant

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TYPE C

Fig 11 Type C socket: No septum exists, and a wide implant must be used to engage the peripheral walls of the socket for stabilization.

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In a recent unpublished study by Smith et al, a high incidence of decay on natural teeth adjacent to molar implants was described.17 The data in this retrospective radiographic study of 300 molar implants suggest that there is a direct correlation between the incidence of decay and the horizontal distance from the abutment-platform connection to the adjacent root. The authors refer to this as the implanttooth distance (ITD; Fig 12). The critical ITD was found to be 4 mm. Cases in which the ITD was at least 4 mm showed a clinically and statistically significant jump in decay rates. As the ITD increased beyond 4 mm, the decay rates continued to rise precipitously (Fig 13). The clinical relevance of these findings is important in implant selection and placement strategy. The distance from tooth to tooth as measured at the alveolar crest across an edentulous molar site is typically greater than 12 mm, often 14 mm or more. If a 6-mm-wide implant is placed, this would leave an ITD on either side of the implant of at least 3 mm in the best of circumstances and, more commonly, 4 mm or greater. Placing the widest-diameter

121 Implant Placement into Molar Extraction Sockets

stability are not typical risks associated with engaging the buccal wall. Often, the septum in a Type B socket is inadequate to stabilize the implant and may be removed entirely, thereby creating a Type C socket, necessitating the use of a wider-diameter implant to engage the intact outer socket walls. In most circumstances, the widest-possiblediameter implant is preferable in an immediate molar site because its diameter at the restorative platform will be closer to that of the tooth it is replacing. This allows for better buccolingual emergence contours of the tooth and smaller interproximal embrasure spaces, thus mitigating problems such as food impaction and poor esthetics. However, it is not always possible to place an ultrawide (> 6 mm) implant due to anatomical limitations of the socket. For example, if in a Type A socket the buccal wall is very thin or missing, it may be best to remain confined to the septum with a narrower-diameter implant to ensure integration. In Type B and Type C sockets, if any one of the outer walls is compromised, a delayed placement protocol, with or without socket preservation grafting, is advised.

Fig 12 The horizontal distance from the implant-abutment connection to the adjacent root surface is referred to as the implant-tooth distance (ITD).

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Fig 14 Implant placed in the palatal root of a maxillary molar.

implant effectively reduces the ITD to minimize the chances of root caries and reduce the potential for food impaction and esthetic difficulties associated with wide embrasures and narrow buccolingual contours.

Alternative Immediate Molar Implant Placement Strategies There are circumstances in which an implant may be placed into one of the root sockets of a multirooted molar. In these cases, the implant is

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partially stabilized by the septum and is therefore considered a Type B socket protocol. In the maxilla, if the tooth being replaced is the terminal tooth in the arch and the buccal plate of bone is compromised, an implant may be placed into the palatal root socket (Fig 14). However, in the majority of cases, the palatal root is in very close proximity to the maxillary sinus and caution must be exercised.18 Additionally, if the implant is placed in the palatal root position, the implant angulation may be unfavorable, making it difficult to have the access opening of the restoration directed through the central fossa as would be ideal. The resulting

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15

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Figs 15 and 16 The healed edentulous space at the mandibular right first molar site measured 15.01 mm from root to root of adjacent teeth. The healed ridge was too narrow buccolingually to support a wide implant. In order to minimize the ITD on both teeth, two 4.1-mm-diameter implants were placed to support a restoration that appeared as a “fluted” molar with a cleansable gingival embrasure between the implants.

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If an ITD of greater than 4 mm is anticipated in any area, it may be advisable to inform the patient of the increased risk for caries and place him or her on a preventive routine of fluoride application in the area to minimize risk. It has been suggested by some that the osteotomy is best performed before the tooth is extracted, drilling through the tooth once the coronal portion of the tooth has been reduced.20 However, this technique assumes that the best position for the implant is in the center of the extraction socket, when, as noted previously, oftentimes it is preferable to shift to an eccentric position for better stability, to reduce ITD, or to avoid compromised outer wall defects. Extracting a tooth after the osteotomy is performed may make the extraction more difficult because of the presence of fragmented rather than intact roots. Drilling the osteotomy through the tooth also precludes the clinician from determining the presence, thickness, and height of the buccal and lingual (or palatal) walls, which, as previously described, is key to determining the proper treatment protocol according to socket type.

Alternative Immediate Molar Implant Placement Strategies

crown contour may end up with a cantilevered portion of the restoration acting as a food trap. Lastly, the palatal root–positioned implant may lead to a restoration whose buccal surface is palatal to the adjacent teeth, creating a shadow visible in a wide smile. In the mandible, there are times when it may be advisable to place the implant in one of the two root sockets of a Type A or Type B molar site. For instance, if the tooth being replaced is the terminal tooth in the arch, it may be beneficial to place the implant in the mesial root socket in order to reduce the ITD between the implant and the tooth mesial to it. Additionally, in many situations the distance between the two teeth on either side of the molar being extracted (when measured at the crest of the alveolar ridge) is too great even for an ultrawide implant to be positioned so that the ITD is less than 4 mm on either or both sides. In these cases, the placement of two implants, each placed within the acceptable ITD range, may be preferable. The restoration then can be designed as either two premolars or a “fluted” molar with a cleansable gingival embrasure between the two implants19 (Figs 15 and 16).

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Clinical Example

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A 55-year-old woman presented with pain at the mandibular right first molar due to a vertical root fracture (Fig 17). Following tooth sectioning and extraction of the mesial and distal roots, a septum of bone was remaining due to the divergent root anatomy of this particular molar. A 5-mmdiameter implant was placed that engaged both the septum and mesial socket (a Type B socket scenario; Figs 18 and 19). A preformed gingival former or iShell (BioHorizons/Vulcan Custom Dental) was used to fabricate a custom healing abutment to maintain the peri-implant tissue architecture (Fig 20). A screw-retained temporary cylinder was subsequently seated and luted to the shell with acrylic resin (Figs 21 and 22). After polymerization of the resin, the prosthetic assembly was removed and seated onto an implant replica for the addition of provisional material to fill the voids and remove the excess (Fig 23). The final custom healing abutment was

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ready for insertion after proper contouring, polishing, removal of the excess PEEK (polyetheretherketone) temporary cylinder, and steam cleaning for 20 seconds (Fig 24). The custom healing abutment was then seated and now supported the peri-implant tissues; grafting is elected if deemed necessary but was not performed in this particular instance (Fig 25).

The first week of healing was uneventful, and recovery was continued for an additional 3 to 4 months prior to first disconnection and final impression making (Figs 26 to 28). First removal of the custom healing abutment showed proper ridge preservation and buccolingual contour (Fig 29). A closed tray implant-level impression was made with

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an addition silicone polyvinyl siloxane material (Flexitime, Kulzer; Figs 30 and 31), and a soft tissue cast was fabricated for final restoration (Fig 32). The definitive metal-ceramic screw-retained restoration was then made; note the support of the tissues on the cast (Figs 33

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and 34). The definitive restoration was inserted 4 months after immediate implant surgery without compromise and with maintenance of the periodontal architecture, thereby eliminating the risk of gingival food impaction (Figs 35 to 37).

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Delayed Protocol for Molar Teeth

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Delayed Protocol for Molar Teeth An alternative to immediate implant placement is the delayed protocol. In this protocol as well, mucoperiosteal flaps are not elevated during extraction, and generally no graft or membrane is placed into the socket. At least

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three months (3 to 6 months depending on the socket size and morphology) are observed between extraction and implant placement to allow for not only full soft tissue growth but also bone fill in the socket space. Sufficiently mature bone must be formed within the socket before an implant can be placed with adequate primary stability. In the event that, at the time of extraction, a buccal (or outer wall) dehiscence

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defect is present, a socket preservation graft may be performed, typically using an allograft bone substitute and either an absorbable or nonabsorbable membrane.21 If a socket preservation graft is performed, the grafted socket must be allowed to heal for a period of 6 months prior to predictable implant placement. Bear in mind that the nongrafted, healed edentulous ridge often will have undergone buccolingual remodeling, which usually results in a ridge too narrow to accept an ultrawide implant.22 When this is the case and the span between the teeth on either side of the edentulous space, when measured at the ridge crest, exceeds the distance that would allow for ITDs of less than 4 mm on either side of the anticipated implant, the clinician should consider grafting the ridge to allow a wider implant or placing two narrowerdiameter implants in the space.

Conclusion Immediate molar implant placement can be a safe, predictable treatment alternative that provides clinical benefits to the clinician as well as enhanced comfort and convenience for the patient. When performed according to the recommended protocol, immediate molar replacement yields success rates no different than the delayed protocol.23 Careful attention to socket morphology, anatomical limitations, and restorative outcomes are all essential elements for successful treatment.

References 1. Becker W, Becker BE. Replacement of maxillary and mandibular molars with single endosseous implant restorations: A retrospective study. J Prosthet Dent 1995;74:51–55. 2. Schwartz-Arad D, Grossman Y, Chaushu G. The clinical effectiveness of implants placed immediately into fresh extraction sites of molar teeth. J Periodontol 2000;71:839–844.

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3. Atieh MA, Payne AG, Duncan WJ, de Silva RK, Cullinan MP. Immediate placement or immediate restoration/ loading of single implants for molar tooth replacement: A systematic review and meta-analysis. Int J Oral Maxillofac Implants 2010;25:401–415. 4. Fugazzatto PA. Implant placement at the time of maxillary molar extraction: Treatment protocols and report of results. J Periodontol 2008;79:216–223. 5. Fugazzatto PA. Implant placement at the time of mandibular molar extraction: Description of technique and preliminary results of 341 cases. J Periodontol 2008;79:737–747. 6. Cafiero C, Annibali S, Gherlone E, et al. Immediate transmucosal implant placement in molar extraction sites: A 12-month prospective multicenter cohort study. Clin Oral Implants Res 2008;19:476–482. 7. Ketabi M, Deporter D, Atenafu EG. A systematic review of outcomes following immediate molar implant placement based on recently published studies. Clin Implant Dent Relat Res 2016;18:1084–1094. 8. Walker LR, Morris GA, Novotny PJ. Implant insertional torque values predict outcomes. J Oral Maxillofac Surg 2011;69:1344–1349. 9. Crespi R, Caparré P, Crespi G, Gastaldi G, Romanos G, Gherlone E. Tissue remodeling in immediate versus delayed prosthetic restoration in fresh socket implants in the esthetic zone: Four-year follow up. Int J Periodontics Restorative Dent 2018;38(suppl): S97–S103. 10. Schwartz-Arad D, Chaushu G. The ways and wherefores of immediate placement of implants into fresh extraxtion sockets: A literature review. J Periodontol 1997;68:915–932. 11. Walker LR, Morris GA, Novotny PJ. Implant insertional torque values predict outcomes. J Oral Maxillofac Surg 2011;69:1344–1349. 12. Vandeweghe S, Ackermann A, Bronner J, Hattingh A, Tschakaloff A, De Bruyn H. A retrospective, multicenter study on a novo wide-body implant for posterior regions. Clin Implant Dent Relat Res 2012;14:281–292. 13. Smith RB, Tarnow DP. Classification of molar extraction sites for immediate dental implant placement. Int J Oral Maxillofac Surg 2013;28:911–916. 14. Kerns DG, Greenwell H, Wittwer JW, et al. Root trunk dimensions of 5 different tooth types. Int J Periodontics Restorative Dent 1999;19:82–91. 15. Tarnow DP, Chu SJ. Human histologic verification of osseointegration of an immediate implant placed into a fresh extraction socket with excessive gap distance without primary flap closure, graft, or membrane: A case report. Int J Periodontics Restorative Dent 2011;31:515–521. 16. Katranji A, Misch K, Wang HL. Cortical bone thickness in dentate and edentulous human cadavers. J Periodontol 2007;78:874–878. 17. Smith RB, Rawdin S, Kagan V. The influence of implant-tooth proximity on decay rates of teeth adjacent to implants in molar sites: A retrospective radiographic analysis of 300 consecutive implants. Compend Contin Educ Dent (in press).

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18. Jung YH, Cho BH. Assessment of the relationship between the maxillary molars and adjacent structures using cone beam computed tomography. Imaging Sci Dent 2012;42:219–224. 19. Mazor Z, Lorean A, Mijiritsky E, Levin L. Replacement of a molar with 2 narrow-diameter dental implants. Implant Dent 2012;21:36–38. 20. Rebele S, Zuhr O, Hurzeler M. Pre-extractive interradicular implant bed preparation: Case presentations of a novel approach to immediate placement at multirooted molar sites. Int J Periodontics Restorative Dent 2013;33:89–96.

21. Avila-Ortiz G, Elangovan S, Kramer KWO, Blanchette D, Dawson DV. Effect of ridge preservation after tooth extraction: A systematic review. J Dent Res 2014;93:950–958. 22. Araújo MG, Sukekava F, Wennström JL, Lindhe J. Ridge alterations following implant placement in fresh extraction sockets: An experimental study in the dog. J Clin Periodontol 2005;32:645–652. 23. Smith R, Tarnow D, Sarnachiaro G. Immediate placement of dental implants in molar extraction sockets: An 11-year retrospective analysis. Compend Contin Educ Dent 2019;40:166–170.

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IN THIS CHAPTER: • Cementation Methods • Impression-Making Techniques • Complications

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Cementation Methods Undetected residual cement remnants in the tissues surrounding an implant can lead to not only soft tissue irritation, inflammation, and swelling but also implant loss1,2 (see chapter 2). Care must be exercised to remove all residual cement if cement-retained restorations are used. One such technique that controls the amount of excess cement was described by Wadhwani and Piñeyro a decade ago.3 In this technique, a duplicate of the final abutment is made as an indirect cementation jig or laboratory die that allows indirect cementation to control the amount of excess cement left remaining in the soft tissues (Figs 1 to 5).

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The crown can be seated on the die extraorally, and most of the excess cement extruded is removed with a cotton roll instead of being left in the soft tissues (Figs 6 and 7). While the cement is still soft and not yet set, the crown is removed from the die and then reseated onto the abutment intraorally, with the correct amount of cement (Figs 8 to 11). The minimal cement remnants are then easily removed from the peri-implant sulcus.

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In the esthetic zone, a custom abutment is mandatory due to the scallop of the bone and soft tissue (Figs 12 to 16). Custom abutments facilitate easier removal of residual cement than stock abutments because they allow greater control over the margins. If a 1-mm-high stock abutment is used, while the restoration may look fine from the facial, it will be impossible to remove cement below the papilla (Figs 17 and 18). 17

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Impression-Making Techniques

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When a provisional restoration is disconnected from an implant for the first time, the mucosal tissues tend to collapse immediately, so how can the peri-implant soft tissue profile be accurately registered in an efficient and predictable manner? Conventional means of using Pattern Resin (GC America) or flowable composite are a clinically acceptable technique provided you have all products and prosthetic components ready chairside. As soon as the provisional restoration is removed and the implant-level impression coping is seated, the Nealon technique can be used to flow the Pattern Resin into the soft tissue socket and register the shape of the peri-implant tissues. First the implantlevel impression analog is quickly inserted onto the implant, and then the Nealon technique (powder and liquid) is used to paint in the Pattern Resin (Figs 19 to 22). Figure 23 shows that the margins of the soft tissue are still quite sharp with this technique, indicating that the tissue has not started to collapse just yet. It is important to avoid flowing the Pattern Resin into proximal undercuts of the adjacent teeth. This will lock the impression coping in place, precluding the use of an open tray technique, which is the preferred method for making an impression because the implant level and analog from the implant can be disconnected for accurate registration. Pattern Resin should only flow into the soft tissue profile.

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If we want to duplicate the subgingival contours of a provisional restoration, the key becomes joining the implant replica or laboratory analog with the provisional restoration, which then allows embedding of this whole assembly into an impression material (Figs 24 to 26). The provisional restoration is embedded adequately where the subgingival shape would be contacting the soft tissue so that an accurate

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Impression-Making Techniques

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representation of that area is in the impression. An implant-level impression coping is then joined to the laboratory analog that is embedded in the impression material, and Pattern Resin can be flowed around that implant-level impression coping, thereby accurately and indirectly registering the subgingival shape of the provisional restoration (Figs 27 to 31).

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Figs 32 to 34  Failed implant due to occlusal overload.

Complications Occlusal overloading

33

An intraoral digital scanner can also be used to make an impression at the tissue level. This digital impression can then be transferred to the laboratory to create a stereolithographic model for reference for the dental technician. This is a great alternative technique when the patient has a strong gag reflex or has highly mobile teeth where conventional methods of impression making are contraindicated.

One of the key elements to implant survival is avoiding occlusal overloading of the provisional restoration during the critical healing phase of 6 to 8 weeks. While patients are instructed not to bite or chew on the provisional restoration, frequently their eating habits are not easily controlled, and food indirectly becomes a weapon. In addition, a patient may have a deep bite or bruxism problem. The patient in Fig 32 did not heed our warnings to avoid biting on his maxillary left canine tooth and was a bruxer as well; consequently, the provisional restoration became loose, and the implant failed due to nonosseointegration (Figs 33 and 34).

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Complications

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Figs 35 to 39  Fractured PMMA restorative component.

Breakage or delamination of the provisional restoration from temporary cylinders The selection of the transitional restorative material is critical to the survival of the provisional restoration. Cement-retained provisional restorations should be avoided postsurgery because cement remnants surrounding the socket can lead to inflammation. Therefore, screw-retained provisional components are recommended and made of either polymethyl

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methacrylate (PMMA), polycarbonate, PEEK, or metal (titanium). PEEK and metal materials are stronger and can withstand greater forces than PMMA and polycarbonate. The patient depicted in Figs 35 to 39 had a provisional restorative component made of PMMA, which is not the most robust material for tooth replacement, that eventually fractured during the healing phase of treatment. This PMMA abutment was then replaced with a pinkcolored titanium cylinder, and the acrylic veneer facing was readapted (Figs 40 and 41).

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Another complication that can occur with provisional restorations is delamination of the acrylic or composite material from the PEEK or metal abutment because these materials are mechanically retained. Figures 6-42 to 6-44 show a clinical situation where the acrylic veneer facing had delaminated after 15 months from delivery. Patients should be informed of the limited service provisional restorations offer, and provisional restorations should not be left in place intraorally for more than 12 months.

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References 1. Wilson TG. The positive relationship between excess cement and peri-implant disease: A prospective clinical endoscopic study.  J Periodontol 2009;80: 1388–1392. 2. Sancho-Puchades M, Crameri D, Ozcan M, et al. The influence of the emergence profile on the amount of undetected cement excess after delivery of cement-retained implant reconstructions. Clin Oral Implants Res 2017;28:1515–1522. 3. Wadhwani C, Piñeyro A. A technique for controlling the cement for an implant crown. J Prosthet Dent 2009;102:57–58.

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IN THIS CHAPTER: TYPE 1 • Case 1: Horizontal fracture of maxillary central incisor • Case 2: Large internal resorption lesion • Case 3: Internal resorption lesion at maxillary central incisor • Case 4: Vertical crown fracture of maxillary central incisor • Case 5: High smile line • Case 6: High smile line and chronic fistula

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TYPE 2 • Case 7: Loss of labial plate • Case 8: Periapical lesion and tooth fracture with necrosis TYPE 3 • Case 9: Loss of labial plate at maxillary central incisor MOLARS • Case 10: External resorption lesion of maxillary first molar • Case 11: Vertical root fracture of mandibular first molar

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TYPE 1 Case 1 Horizontal fracture of maxillary central incisor The 46-year-old woman depicted in this case series had a high smile line and needed immediate tooth replacement for her maxillary left central incisor due to palatal swelling and horizontal fracture on the palatal side of the root coincident with the post and core restoration (Figs 1 to 3). Before atraumatic extraction, an alginate impression of the tooth was taken, and acrylic resin was painted in with the powder and liquid Nealon technique using a sable brush to create a tooth form shell (Fig 4). The acrylic resin sets quickly, and then it can be removed from the impression (Fig 5). A bur was then used to trim away all the excess material to the outline of the free gingival margin (FGM; Figs 6 and 7). The proximal areas were left intact to the incisal edge of the resin shell.

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Atraumatic tooth extraction was then performed via sharp dissection, which severs the supracrestal gingival fibers (Figs 8 and 9). Extraction forceps were used to remove the clinical crown; note the fractured root (Figs 10 to 13). Small beak extraction forceps were used to acquire a purchase on the residual root surface to remove it entirely (Fig 14). The individual segments of the fractured tooth were removed with the labial plate intact (Fig 15).

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Once the socket was thoroughly debrided and cleaned, the implant was placed with a palatal bias and 3 mm from the FGM (Figs 16 to 18). While it was not critical that the gap be grafted from the standpoint of survival of the implant or osseointegration, esthetic concerns did mandate grafting the labial gap to maintain the shape of the ridge and prevent its collapse as well as breakdown of the peri-implant soft tissues (see chapter 2). A 4-mm PEEK (polyetheretherketone) abutment was placed in conjunction with a 5-mm implant. Platform-switched implant designs are helpful in enabling the seating of prosthetic components. Because extraction socket implants are often placed more to the palatal side and therefore engage this aspect of the bone plate, often some modification is required to the temporary implant components that are screw retained. Here the most incisal-facial aspect of the PEEK material

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had to be altered (Fig 19). If making this adjustment, it should be done extraorally to prevent any PEEK particles from entering the socket as foreign bodies, which will cause an adverse healing response. Once the abutment was adjusted, the acrylic shell was modified to accommodate the cylinder, seated, and relined (Figs 20 to 22). Vaseline was lightly brushed onto the adjacent

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teeth prior to relining to facilitate removal of the shell, and more monomer was added to the shell to ensure adequate mechanical retention. It is important to perform this step to register the position of the proximal contact areas (Fig 23). This will not only prevent micromotion but also prevent food impaction, thereby limiting the potential for infection of the graft material. Here is where good implant stability and high insertion torque is valuable, because relining this provisional restoration will require force to remove it, and it is critical to not dislodge the implant during this procedure. The provisional restoration was then seated onto a laboratory replica or analog, and the mesial and distal proximal contact areas were marked with a red wax pencil (Fig 24). When marking the contact areas, it is important to make sure that the provisional restoration is properly secured and mechanically retained to the temporary implant cylinder. The rationale for marking the contact areas is to provide an orientation guide during trimming. Voids in the provisional restoration can be added to extraorally, and a heatless stone grinding wheel and

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laboratory diamond bur on a straight handpiece are used to remove excess restorative material and refine the crown contours (Figs 25 to 29). Once the trimming is completed, the provisional restoration must be tried in the patient’s mouth. It is critical that the subgingival anatomy is recreated properly with the provisional restoration. If the contour is deficient, then more acrylic is required to construct the proper contour prior to gap bone grafting (Figs 30 to 33). A deficient

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contour will encourage collapse. Because this restoration was replacing a central incisor, it was important to add some custom colorization; Minute Stain (Taub) is very compatible with acrylic resins, so it was added only on the part of the tooth that was supragingival (Fig 34). It is

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not necessary to stain the subgingival part, and in fact it may negatively affect the tissue health, so it is best avoided. A super glaze was then brushed on to finish the extrinsic colorization, providing a seal to the surface of the provisional restoration (Fig 35).

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Once the provisional restoration is finalized, it is removed from the mouth, and the labial gap is grafted. Note that the bone zone as well as the tissue zone is grafted. A platform-switched healing abutment with a flat profile was used, which allows the surgeon access to the gap without entrapping graft material in the prosthetic connection (Fig 36). Again, the gap was only grafted for esthetic reasons to minimize the amount of facial ridge collapse; the graft has no bearing on implant survival or osseointegration (see chapter 2). In this specific case, a xenograft in a collagen matrix (Bio-Oss Collagen, Geistlich) was used (Figs 37 to 39). This material sometimes can be a soft tissue

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irritant (about 10% of cases). The key element in esthetic treatment is grafting to the level of the FGM (Figs 40 to 42). The dual-zone technique precludes the need for a connective tissue graft, which entails an additional procedure, time, expense, and potential morbidity to the treatment. The provisional restoration was then fully seated and serves as a prosthetic socket sealing device (see chapter 2). The bone graft material was extended beyond the bone crest into the tissue zone, and any excess was removed with a probe (Figs 43 to 47). This procedure is uneventful, highly predictable, and minimally invasive with little to no postoperative complications or swelling.

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The healing period for dual-zone therapy is about 4 to 6 months, after which the ridge had a nice shape, aided by the fact that this patient had presented with a thick periodontal phenotype (Figs 48 and 49). The definitive shade was taken at this appointment (Fig 50). At first disconnection of the provisional restoration, bountiful peri-implant soft tissue thickness was preserved and achieved (Figs 51 and 52). An implant-level impression was then made

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using a platform-switched impression coping, and a soft tissue cast was made in the dental laboratory (Figs 53 to 55). At this point it was clear that a cement-retained definitive restoration would be required due to the position and angulation of the screw hole. Therefore, an angulated, screw-retained custom abutment was fabricated out of metal-ceramic gold alloy to support a metal-ceramic crown (Figs 56 to 61). As German Gallucci has shown, it does not really matter which material is used for the definitive restoration as long as the white and pink esthetic scores are satisfactory. Patients often cannot tell the difference between materials as long as their restoration is esthetically acceptable (Fig 62). For this particular patient, the abutment was gold plated to add a yellow hue and counteract the color difference of the gray metal abutment through the soft tissues (Figs 63 to 66). This is not a difficult process and only takes a few extra minutes. First an electrode is used to heat the gold plating solution (Dentsply Gold Plating Solution), which energizes the particles. This solution is then touched to the surface of the gold alloy, where the gold ions from the solution transfer to the surface, turning it from gray to yellow. Note that gold plating only works on semi- or high-noble alloys. A titanium abutment would have to be sent back to the manufacturer to be anodized and nitrate coated. The abutment was then steam-cleaned and seated in place intraorally (Fig 67). The cementation technique of the definitive restoration was critical because excess cement can lead to adverse outcomes (see chapter 2). Implants do not have the Sharpey and gingival fibers of natural teeth to prevent cement migration; permanent cements can be transparent and very hard to visualize, and packing cord can induce gingival recession. Therefore, a cementing die was created. First the internal surface of the definitive restoration was coated with a lubricant so that bis-acrylic material could be injected into the crown and the laboratory die seated (see Fig 67). After it set completely, it was removed, and the lubricant

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was steam-cleaned off the die and inside the crown (Fig 68). The crown was then cemented onto the laboratory die indirectly extraorally and almost seated fully (Fig 69). While the cement was still unset, the excess was cleaned off with cotton swabs, and the crown was removed and reseated onto the abutment already secured in the patient’s mouth (Fig 70). Note the final outcome of the definitive restoration (Figs 71 to 75). Survival, integration, and esthetics are a reality with the dual-zone protocol.

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Case 2 Large internal resorption lesion The 44-year-old woman portrayed in this case series had a high smile line and needed immediate tooth replacement for her maxillary left central incisor due to palatal swelling and a massive internal resorption lesion (Figs 1 to 4). Atraumatic tooth extraction was then performed; note the resorption lesion that had perforated the palatal aspect of the tooth (Figs 5 to 9). Once the socket was thoroughly debrided and cleaned, the implant was placed with a palatal bias and 3 mm from the FGM (Figs 10 to 14). The iShell (BioHorizons/Vulcan Custom Dental) device was used in the fabrication of the provisional restoration (Figs 15 to 26; see chapter 2). Dual-zone grafting was employed to maintain the ridge volume and shape, and the provisional restoration was used as a prosthetic socket sealing device (Figs 27 to 34).

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The socket was allowed to heal for 4 months prior to first disconnection and impression making (Figs 35 to 40). A soft tissue cast was fabricated, and a cement-retained all-ceramic restoration was made (Figs 41 to 43). An indirect cementing jig was made from bis-acrylic resin as described in chapter 6 (Figs 44 to 49). The cleaned/disinfected ceramic abutment was seated intraorally, and the crown was cemented with provisional cement with minimal excess (Figs 50 to 52). Figure 53 shows the 3-year recall. The patient was very pleased with the results.

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Case 3 Internal resorption lesion at maxillary central incisor A 25-year-old woman presented to the office with a very high smile line and a thin periodontal phenotype. This patient required immediate tooth replacement therapy of the maxillary left central incisor due to an internal resorption lesion (Figs 1 to 3). Atraumatic tooth extraction was performed, and an implant was placed with a palatal bias and 3 mm from the FGM (Figs 4 to 9). The iShell device was used in the fabrication of the provisional restoration (Figs 10 to 21; see chapter 2). Dual-zone grafting was employed

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to maintain the ridge volume and shape as well as to thicken the thin peri-implant soft tissues (Figs 22 to 26). The socket was allowed to heal for 4 months prior to first disconnection and impression making (Figs 27 to 31). A soft tissue cast was fabricated, and a screw-retained metal-ceramic restoration was made and gold plated (Figs 32 to 37). Intraoral views of the definitive restorations are shown in Figs 38 and 39. A direct composite resin restoration was made on the mesial-facial aspect of the right central incisor to replace the preexisting defective restoration. A posttreatment periapical radiograph is shown in Fig 40. Figure 41 shows the final smile view of a pleased patient with a very high smile line.

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Case 4 Vertical crown fracture of maxillary central incisor This 28-year-old woman with an average smile line presented requiring immediate tooth replacement for her maxillary left central incisor due to a clinical crown vertical fracture (Figs 1 to 5). Atraumatic tooth extraction was performed as previously described in chapter 2 (Figs 6 to 10). Once the socket was thoroughly debrided and cleaned, an implant was placed with an incisal bias using a subcrestal angle correction macro implant design (Co-Axis, Southern Implants) with a restorative platform at +12 degrees (Figs 11 and 12). The implant is premounted with an orientation mark on the labial aspect of the implant and a 3-mm-depth laser line on the implant mount (Figs 13 and 14). Figure 15 shows the implant after placement

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with the top of the external hex connection toward the direct facial, 3 mm from the FGM. A PEEK screw-retained cylinder was seated; note the angle correction provided by the implant design (Fig 16).

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The iShell device was used in the fabrication of the provisional restoration (Figs 17 to 24). The provisional restoration must be completely adapted to the soft tissue surface to seal the

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graft material (Fig 25). A flat healing abutment was placed onto the implant, dual-zone grafting was used to retain the ridge volume and shape, and the provisional restoration was reseated as the prosthetic socket sealing device (Figs 26 to 29). Periapical and CBCT images were taken immediately posttreatment (Figs 30 and 31). The use of the subcrestal angle correction (SAC) implant reduced the risk of apical perforation of the extraction socket (see Fig 31). Healing at 1 week (Figs 32 and 33) and 4 months (Figs 34 and 35) was uneventful. First disconnection shows bleeding, denoting tearing of the biologic attachment to the provisional

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restoration (see chapter 2), and implant-level impression making was performed (Figs 36 to 39). A soft tissue cast was fabricated, and a screw-retained metal-ceramic restoration

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was made (Figs 40 to 44). The crown was cleaned/disinfected prior to seating intraorally, and the patient was very satisfied (Figs 45 to 48).

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Of interest to note is that with SAC implant designs, drilling is at the incisal edge position, yet the crown is screw retained due to the angle correction at the implant level versus the abutment level, thereby avoiding the need for cement and the potential associated risks (see Fig 46).

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Case 5 High smile line This 41-year-old woman with a high smile line presented with a loose crown at the maxillary right central incisor (Figs 1 and 2). The periapical radiograph revealed interproximal recurrent tooth decay around an existing post and core restoration (Fig 3). In addition, the prior endodontic therapy due to trauma of this tooth led to discoloration of the root and bleed-through to her thin gingiva, contributing to an unesthetic appearance. It was decided that immediate tooth replacement was the correct treatment of choice using an SAC implant (Co-Axis) based on the CBCT (Fig 4). Atraumatic tooth extraction was then performed as previously described in chapter 2 (Figs 7 5 to 8).

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Once the socket was thoroughly debrided and cleaned, the implant was placed with an incisal bias with a restorative platform at +12 degrees (Figs 9 to 14). The external connection implant is premounted with an orientation mark on the labial aspect of the implant and a 3-mm-depth laser line on the implant mount (see Figs 11 to 14). After implant placement, the top of the external hex connection was toward the facial, 3 mm from the FGM (Fig 15). A PEEK screw-retained cylinder was seated; note the angle correction provided by the implant design (Figs 16 and 17). The iShell device was used in

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the fabrication of the provisional restoration (Figs 18 to 31; see chapter 2). The provisional restoration must be completely adapted to the soft tissue surface to seal the graft material (Figs 32 and 33).

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A flat healing abutment was placed onto the implant, dual-zone grafting was used to maintain ridge volume and shape, and the provisional restoration was reseated as the prosthetic socket seal device (Figs 34 to 39). Periapical and CBCT radiographs were taken immediately posttreatment (Figs 40 and 41). The use of the

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SAC implant reduced the risk of apical perforation of the extraction socket (see Fig 41). At 4 months, healing was uneventful, and the shade was taken (Figs 42 to 44). First disconnection shows bleeding, denoting tearing of the biologic attachment to the provisional restoration (see chapter 2), and implant-level

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impression making was performed (Figs 45 to 49). A soft tissue cast was fabricated, and a screw-retained metal-ceramic restoration was made (Figs 50 to 64). The crown was cleaned/ disinfected prior to seating intraorally, and the patient was very satisfied with the outcome (Figs 65 to 69).

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Of interest to note is that with SAC implant designs, drilling is at the incisal edge position, yet the crown is screw-retained due to the angle correction at the implant level versus the abutment level, thereby avoiding the need for cement and the potential associated risks (see Figs 64 and 67).

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Case 6 High smile line and chronic fistula This 37-year-old woman with a high smile line presented with a chronic fistula associated with the endodontically treated maxillary left central incisor (Figs 1 to 4). The CBCT radiograph revealed a fenestration midway in the labial plate toward the apex (Fig 5). The patient was unhappy with the tooth discoloration from prior trauma and endodontic treatment, the gingival levels, and the position of the central incisors relative to the adjacent teeth due to her Class II, division 2 relationship of the anterior dentition. The treatment plan included immediate tooth replacement of the left central incisor and a no-preparation veneer on the right central incisor with added gingival contour to change the gingival levels of the central incisors as well as to correct the shade of the teeth. A deep conical connection SAC implant (Co-Axis)

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was selected based on the CBCT (see Fig 5). The labial plate fenestration did not communicate with the tooth sulcus (Fig 6).

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Atraumatic tooth extraction was performed, and the residual chronic granulomatous lesion was removed (Figs 7 to 9). The implant was subsequently placed with an incisal bias with a restorative platform at +12 degrees (Figs 10 to 15). The implant is premounted with an orientation groove on the labial aspect of the implant and a 3-mm-depth laser line on the implant mount (see Figs 10 to 14). After implant placement, the top of the deep conical connection with an orientation dot facing toward the facial was 3 mm from the

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FGM (see Fig 15). The iShell device was used in the fabrication of the provisional restoration (Figs 16 to 27). A PEEK screw-retained cylinder was seated; note the angle correction provided by the implant design (see Fig 17). The provisional

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restoration must be completely adapted to the soft tissue surface to seal the graft material (Fig 28). The provisional restoration on the left central incisor was intentionally adapted to the facial to correct the final position of the tooth

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as well as to avoid any occlusal loading of the provisional restoration during healing (Fig 29). A flat healing abutment was placed onto the implant, dual-zone grafting was used to maintain ridge volume and shape, and the provisional restoration was reseated as the prosthetic

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socket seal device (Figs 30 to 32). Periapical and CBCT radiographs were taken immediately posttreatment (Figs 33 and 34). The use of the SAC implant reduced the risk of apical perforation of the extraction socket (see Fig 34).

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At 5 months, healing was uneventful, and the patient was pleased (Figs 35 to 37). First disconnection shows bleeding, denoting tearing of the biologic attachment to the provisional restoration, and implant-level impressions were made (Figs 38 to 43). A soft tissue cast was fabricated, and a screw-retained metal-ceramic restoration was made for the left central incisor and an all-ceramic veneer for the right central

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incisor (Figs 44 to 46). The implant screwretained crown was cleaned/disinfected prior to seating intraorally with healthy peri-implant soft tissues (Figs 47 and 48). Figures 49 and 50 show the corrected position of the central incisor teeth prior to bonding of the ceramic veneer restoration on the right central incisor. The final restorations were seated, making for a happy patient (Figs 51 to 54).

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This 29-year-old man presented with a fractured and extruded maxillary left central incisor (Figs 1 to 5). The lesion was quite extensive in size, involving loss of the labial bone plate and a type 2 extraction socket (see chapter 3), as seen on radiographic examination (Figs 6 and 7). Atraumatic flapless tooth extraction was then performed, and the socket was thoroughly cleaned and debrided of all the granulomatous tissue (Figs 8 to 13). Figure 14 demonstrates the absence of the labial bone plate. A lasermicrogrooved 5.8 × 13.0–mm implant (Tapered Plus, BioHorizons) was placed toward the palatal aspect of the socket (Figs 15 and 16).

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The iShell device was used in the fabrication of the provisional restoration as previously described (Figs 17 to 37). The PEEK temporary cylinder was modified accordingly to fit the shell into position (see Fig 21). A flat healing

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abutment was placed, and a cross-linked collagen membrane was fitted to completely cover and extend beyond the dentoalveolar defect (type 2c-UU) (Figs 38 to 43). The membrane reconstructs a type 2 socket into essentially a

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type 1. Small-particle mineralized cancellous allograft was used to graft between the palatal aspect of the membrane and labial surface of the implant (Figs 44 and 45). Again, the provisional

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43

45

restoration in nonocclusal loading was used to seal and protect the graft and membrane during the healing period of 6 months (Figs 46 to 49).

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191 Case 7

47

48

49

1 WEEK

50

51

6 MONTHS

52

Healing was uneventful at 1 week and 6 months (Figs 50 to 53). The shade was taken prior to impression making (Figs 54 and 55). An implant-level impression was made using the iShell device to hold the peri-implant tissues in

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53

their noncollapsed state (Figs 56 to 58). The shell was affixed to an impression coping with flowable composite and then reseated into the impression (Figs 59 to 61).

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55

56

57

58

59

60

A gypsum soft tissue cast was made, and a metal-ceramic screw-retained crown was fabricated (Figs 62 to 72). The final intraoral and extraoral photographs and radiograph of the completed implant crown restoration show

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61

esthetic integration with the surrounding dentition and stable bone levels (Figs 73 to 77). This treatment was performed in one surgery one time, as exemplified in chapter 3.

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65

66

67

68

69

70

71

193 Case 7

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72

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74

76

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75

77

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2

195

5

Case 8

4

3

6

Case 8

12

Periapical lesion and tooth fracture with necrosis A 25-year-old man presented with a fractured maxillary left central incisor with a preexisting periapical lesion (Figs 1 to 4). The patient was given pretreatment antibiotics. The supragingival fibers were severed with sharp dissection using a no. 15c scalpel, and the tooth was removed atraumatically without flap elevation (Figs 5 to 7). After thorough socket debridement

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7

with a surgical spoon excavator, a 5.8 × 13.0–mm implant was placed to the palatal aspect of the extraction socket (Fig 8). A full-contoured provisional restoration was made with nonocclusal

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8

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9

12

10

13

loading (Figs 9 to 13). Dual-zone grafting was performed as previously described in chapter 2 (Fig 14). One-week postoperative healing was uneventful (Fig 15). However, at 4 months posttreatment, the implant was mobile and had extruded, and a radiolucency was evident on the periapical radiograph (Figs 16 and 17). The

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11

14

provisional restoration was removed, and a discoloration was noted at the labial crest of the bone plate (Figs 18 and 19). This area was diagnosed as necrotic hard tissue and subsequently removed (Fig 20). The socket transformed from a type 1 to a type 2 defect (Fig 21; see chapter 3).

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1 WEEK

15

16

197 Case 8

17

18

NECROTIC BONE

19

20

21

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22

24

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25

27

28

A longer inverted body-shift design implant with a subcrestal angle correction feature was selected to replace the prior implant; the palatal aspect of the socket could be engaged more aggressively with this implant design (Figs 22 and 23). Extended-length solid shank drills were

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26

used to create the precise osteotomy, because only the apical part of the implant was providing primary stability. The incisal edge position was used as a point of reference when drilling the osteotomy as well as during implant placement (Fig 24). Because the bone quality was type III density, a decision was made to undersize the osteotomy to a 4.5-mm diameter instead of 5.0 mm. Subsequently, a 13-mm implant with an inverted body-shift design was placed that had a 5-mm-diameter apical portion for roughly 50% the implant length and a 4-mm coronal cylindrical portion with an SAC feature (Inverta IV-DC4012d-5013, Southern Implants) to ensure a screw-retained restoration (Figs 25 to 28). This implant had a 12-degree angle correction of the implant-abutment interface and therefore was preassembled with a countermatching implant mount (see Fig 23). The inherent SAC feature redirects the restorative position of the prosthetic screw to the cingulum of the tooth (see Figs 27 and 28). An alignment groove on the facial aspect of the implant mount helps orient the implant into the proper position (see Fig 26).

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30

199 31

32

Case 8

33

The crown portion of the original provisional restoration was reused and attached to a PEEK implant cylinder with full labial restorative contour to support the peri-implant soft tissues (Figs 29 to 34). A cross-linked collagen membrane was placed within the residual socket walls on the facial aspect to cover the bony defect, thereby creating a type 1 scenario out of a type 2 socket (Figs 35 to 37). Then small-particle mineralized cancellous allograft was placed between the membrane and the labial surface of the implant as if it were a type 1 socket with dual-zone grafting (Figs 38 to 40).

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34

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37

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39

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40

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42

43

1 WEEK

201 Case 8

44

The provisional restoration was then replaced after dual-zone socket grafting to contain and protect the graft during the healing phase (Fig 41). The provisional restoration was re-evaluated to make sure it was not in occlusal contact during maximum intercuspal position as well as lateral excursive movements. This is a critical step in treatment to ensure implant survival with extraction socket implants. A CBCT scan taken immediately after treatment revealed a labial bone plate thickness of 2.4 mm at the implant-abutment interface (Fig 42). A periapical radiograph revealed a tooth-to-implant distance from the distal aspect of the central incisor implant to the adjacent central and lateral incisors of 3.1 mm (Fig 43). The patient continued the antibiotic regimen for 1 week

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posttreatment and was instructed to not brush the surgical site for 5 to 7 days. At the first postoperative appointment the following week, the wound healing was evaluated and the occlusion rechecked; a small dehiscence of the soft tissue was noted with slight recession (Fig 44). The implant was allowed to heal for a full 4 months, and then the submergence profile of the provisional restoration was undercontoured to allow the free gingival margin of the soft tissue to migrate more incisal (Figs 45 and 46). At the 6-month interval prior to first abutment disconnection and final impression making, the soft tissue margin was recontoured to the appropriate shape with electrosurgery (Figs 47 to 49). After seating an analog implant-level impression

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45

46

6 MONTHS

47

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49

50

51

coping, flowable composite was used to register the submergence profile of the peri-implant soft tissues (Figs 50 to 52). The use of electrosurgery not only allowed for proper contouring of the soft tissues but also uneventful healing (Figs 53 and 54). 52

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53

203 Case 8

54

A soft tissue gypsum cast was made in the laboratory that allowed a screw-retained metal-ceramic implant restoration to be fabricated (Figs 55 to 65). The color, texture, and form of the restoration were made to mimic that of the contralateral tooth. A mesial indirect composite veneer was also created to manage

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the size and space discrepancy between the two central incisors (Figs 66 to 72). The mesial indirect composite restoration was tried in prior to bonding with a transparent resin cement (Figs 73 to 75). The patient was very pleased with the final outcome (Figs 76 to 80).

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55

204 58

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61

62

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65

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VENEER

67

66

205 Case 8

69

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72

71

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VENEER TRY-IN

73

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75

76

77

DEFINITIVE RESTORATION

78

79

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80

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207 Case 9

2

3

TYPE 3 Case 9 Loss of labial plate at maxillary central incisor This 25-year-old man presented with marginal inflammation, 1 to 2 mm of midfacial recession, and loss of the labial bone plate at the maxillary right central incisor (type 2c-UU), as seen on CBCT and periapical radiographs (Figs 1 to 5). The patient had a low smile line with a lack of incisal tooth display, so the treatment plan included a provision to extend the length of the two central incisors with veneer restorations. Following removal of the clinical crown, the remaining root tip was carefully removed as per the technique described in chapter 2, using

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4

5

sharp dissection and periodontal elevators (Figs 6 and 7). The soft tissues were kept intact, and the absence of the labial bone plate was evident (Figs 8 to 10). An implant was placed, and the iShell device (see chapter 2) was used to restore the socket shape and subgingival contour to the preextraction situation and then joined

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6

7

8

9

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208

10

to the implant PEEK temporary cylinder with acrylic resin (Figs 11 to 16). An acrylic veneer facing was joined to the PEEK temporary cylinder and extrinsically characterized with unfilled colored resin to create the provisional clinical crown, which was relined slightly to the

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facial to be out of occlusal contact (Figs 17 and 18). At this point, it is important to undercontour the midfacial aspect of the provisional restoration at and below the cementoenamel junction to encourage the peri-implant gingival

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11

12

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14

Case 9

15

16

17

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18

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22

23

25

24

26

tissues to migrate more coronal (Figs 19 to 21). At this juncture, the esthetics and occlusion of the provisional crown must be assessed (Figs 22 and 23). The provisional crown was then removed from the implant and replaced with a flat-contour healing abutment, and a cross-linked

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collagen membrane was fitted and placed labial to the implant to the level of the FGM to reconstruct the lost labial bone plate, as described in chapter 3 (Figs 24 to 26). A small-particle mineralized cancellous allograft was placed between the implant and cross-linked collagen

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27

28

211 30

31

32

33

34

membrane (Figs 27 and 28). The graft particles were allowed to clot prior to removal of the flat-contour healing abutment (Figs 29 and 30). Then the healing abutment was removed and replaced with the provisional restoration as per the prosthetic socket seal concept (see chapter 2) (Figs 31 and 32).

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Case 9

29

The site was allowed to heal for 8 months prior to the first disconnection of the provisional restoration (Fig 33). The reconstruction of the destroyed labial plate after removal of the provisional restoration is clearly shown in Fig 34. Subsequently, an implant-level impression was made, a gypsum cast poured, and a

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35

36

37

38

39

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metal-ceramic framework fabricated (Figs 35 to 38). Shade-matching was performed, and the metal framework was veneered with feldspathic ceramic (Figs 39 and 40). Two lithium disilicate veneer restorations were also made to increase the length of the implant crown as well as the natural left central incisor crown to correct the incisal length of these teeth, if the patient so desired in the final outcome (Figs 41 to 44). The veneers could be inserted without commitment and cementation to evaluate patient acceptability of the

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increased incisal length (Figs 45 to 50). If the patient decided not to extend the incisal length, then the metal-ceramic crown on the implant could be finished (see Fig 45). However, the patient was pleased with the incisal length correction and decided to bond the veneers definitively after shade modification (Fig 51). The veneer extension was bonded to the metal-ceramic crown in the laboratory with resin cement, the excess cement was removed with rubber rotary instruments, and then the restoration was polished (Figs 52 to 59).

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41

213 Case 9

42

43

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49

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51

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53

215 Case 9

58

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55

56

57

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60

62

63

The definitive implant crown as well as the veneer restoration on the left central incisor were delivered, and the patient was pleased with the final esthetic outcome (Figs 60 to 63).

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This treatment was delivered in one surgical intervention (one surgery, one time) with a predictable protocol as taught in this book.

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2

217 Case 10

3

4

MOLARS Case 10 External resorption lesion of maxillary first molar This 57-year-old man presented with an external resorption lesion associated with the midpalatal aspect of the maxillary left first molar (Figs 1 and 2). The tooth was trisected (see chapter 5) and removed atraumatically (Figs 3 to 5). After socket cleaning, it was determined that the molar socket classification was a Type C socket (see chapter 5); therefore, an ultrawide implant (MAX, Southern Implants) was placed, engaging the lateral walls (Figs 6 to 8). An iShell device was used to fabricate the custom healing abutment as described in chapter 2 (Figs 9 to 14). The site was allowed to heal for 4 months prior to impression making (Figs 15 to 18). A screw-retained all-ceramic monolithic restoration with a titanium base was made as the final restoration (Figs 19 and 20).

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5

6

7

8

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9

10

11

CUSTOM HEALING ABUTMENT

13

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14

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4 MONTHS

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219 Case 10

17

18

19

20

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3 5

4

Case 11 Vertical root fracture of mandibular first molar This 68-year-old man presented with pain on percussion associated with a mandibular right first molar with a prior dental history of endodontic treatment (Figs 1 and 2). The patient had a vertical fracture of the distal root (see Fig 2). The metal-ceramic crown was sectioned (Figs 3 to 5), and the vertical root fracture was evident at the distobuccal aspect of the root (Fig 6). The roots were hemisected and removed without flap elevation (Figs 7 to 14). The socket was thoroughly debrided of all the granulomatous tissue (Figs 15 and 16) and prepared to receive an 8.0 × 10.0–mm tapered ultrawide implant (Tapered Immediate Molar Implant, BioHorizons) with an insertion torque value of 40 Ncm (Figs 17 to 21).

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6

9

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11

Case 11

10

8

12

13

15

16

14

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19

ULTRAWIDE IMPLANT

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20

22

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21

The iShell device was used to capture and maintain the peri-implant soft tissues. The shell was seated first, the temporary cylinder was tried in separately (Figs 22 to 24), and then both pieces were fitted together with the shell luted to the temporary cylinder with autopolymerizing acrylic resin (Figs 25 to 29). The acrylic resin was purposely not completely filled around the temporary cylinder to allow the hem to be steam cleaned away (Figs 30 to 32). The shell assembly was attached to a laboratory analog, and the remaining voids were filled in with acrylic resin (Figs 33 to 36). The excess temporary cylinder at the occlusal aspect was removed with a separating disc, and the custom healing abutment was finished, polished, and cleaned prior to intraoral try-in (Figs 37 to 39).

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24

223 Case 11

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26

27

29

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LABORATORY ANALOG

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39

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DUAL-ZONE GRAFTING

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41

225

43

1 WEEK

3 MONTHS

44

45

After fit verification, the custom healing abutment was removed, and a straight healing abutment was placed to allow dual-zone grafting (Fig 40 and 41). The custom healing abutment was replaced to contain and protect the graft material for the subsequent 3 months (Figs 42 and 43). Healing at 1 week and 3 months was uneventful (Figs 44 and 45). An implantlevel impression was made, and a soft tissue cast was created in the laboratory that allowed

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Case 11

42

construction of a monolithic all-ceramic restoration affixed to a titanium base screw-retained restoration (Figs 46 to 50). The definitive restoration was seated and radiographically confirmed; the screw was torqued to 32 Ncm; and the access hole was filled with composite resin (Figs 51 to 53). Note the preservation of the buccogingival tissue contours, eliminating the potential for food impaction.

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48

49

52

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50

51

FINAL

53

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Index Page numbers followed by “f” denote figures and “t” tables.

C

Absorbable membranes, 84 Abutments biologic width, 67f ceramic, 64f custom healing description of, 81–82 with dual-zone grafting and iShell, 55–56, 55f–57f fabrication of, 80f illustration of, 57f in prosthetic socket sealing, 46, 47f removal of, 125 implant and, interface between, 64 metal, 65f “one abutment, one time” approach, 69 overcontouring of, 28 selection of, 64, 65f transmucosal, 30 Acrylic resin cells that adhere to, 62 description of, 56 Acrylic veneer facing, 139 Allografts corticocancellous, 45 definition of, 44 Alloplasts, 44 Alveolar ridge augmentation of connective tissue grafts for, 31 implant placement with, 93 dimensional change of, 37, 38f–39f Ankylosed teeth, 65–66 Anterior maxilla, 69 Apical pressure necrosis, 71 Atraumatic tooth extraction, 21, 79, 85f, 142, 159, 170, 179 Autografts, 44

CAD/CAM, 105 Cancellous allograft, 112 CBCT, for extraction socket management, 14, 14f Cementation, 131–133 Cementing die, 151f Cementoenamel junction, 25, 111, 208 Cement-retained provisional restorations, 64, 64f, 95, 137 Cement-retained restorations, 24 Ceramic abutment, 64f Chronic fistula, high smile line and, 178–185, 178f–185f Clinical crown fracture, 21, 21f Coaxial implants, 69, 69f Collagen membranes absorbable, 84 ice cream cone technique for, 84–87, 84f–87f, 93f nonabsorbable, 84 Color difference, 41 Complications occlusal overloading, 136, 136f provisional restorations, 139 Composite resin, 56 Connective tissue grafts advantages of, 31 around implants, 31 disadvantages of, 31 Corticocancellous allograft, 45 Crestal bone loss, 11 Cross-linked collagen membrane, 80f, 82, 85, 199 Custom healing abutment description of, 81–82 with dual-zone grafting and iShell, 55–56, 55f–57f in esthetic zone, 133 fabrication of, 80f illustration of, 57f, 218f in prosthetic socket sealing, 46, 47f removal of, 125 Cylindrical implants, 66

B ß-tricalcium phosphate, 44 Biologic width, 67f, 68, 68f, 70 Bone gap distance of. See Gap distance. hard tissue grafting of, 37 Bone grafts allografts, 44 alloplasts, 44 autografts, 44 for dual-zone socket management, 44f, 44–45 xenografts, 44, 45f Buccal fistula, 81 Buccal plate dehiscence of, 87 description of, 12

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227 

A

D Delayed tooth replacement therapy flap design for, after ridge healing flap technique, 93–97 punch technique, 89–92, 90f–91f with immediate provisional restoration, 88–89 immediate tooth replacement therapy versus, 2–3 for molars, 127–128 protocol for, 3t survival rates for, 2 in type 2 extraction sockets, 84–89 Dentoalveolar dehiscence defects, 77 Dermis allografts, 31 Digital impression, 136

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Dual-zone grafting custom healing abutment with, 55–56, 55f–57f description of, 153, 196 full provisional restoration with, 58–61, 201 Dual-zone socket management benefits of, 42–43 bone graft materials for, 43–45, 44f bone zone, 42 definition of, 42 tissue zone, 42 Dual-zone therapeutic concept, 106, 148

E

Index

228

Edentulous ridges, connective tissue grafts around, 31 Emergence profile, implant position effects on, 25–26 Esthetic zone, custom healing abutment in, 133 Extended beak forceps, 22f Extended-tip extraction forceps, 21f External resorption lesion, at maxillary first molar, 217–219, 217f–219f Extraction forceps, 142 Extraction sockets buccolingual dimensional change in, 37 classification of, 12, 13f diagnostic aids for management of, 14–15, 14f–15f epithelium of, 33 periodontal probes for, 15, 15f type 1. See Type 1 extraction sockets. type 2. See Type 2 extraction sockets. type 3. See Type 3 extraction sockets. wound healing of, 20

F Facial bone gap, 32 Faciopalatal ridge collapse, 41–42 Fibroblasts, 62 Fistulae, 65 Flapless tooth extraction, 19–21 Flapped tooth extraction, 19–21 Flat noncontoured healing abutment, 53f Free gingival margin buccal fistula above, 81 description of, 21, 25f, 40, 56, 210 Full provisional restoration with dual-zone grafting and iShell, 58–61

G Gap distance importance of, 36 wound healing and, 32–37 Gingiva discoloration of, 41 recession of, 101, 149 thickness of, 40 Gold plating, 65f, 149, 151f Guided bone regeneration, 84

H Healing abutment custom. See Custom healing abutment. flat contoured, 113 flat noncontoured, 53f

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provisional restoration and, 62 replacement of, 80f straight, 95 titanium, 106 High smile line case study of, 170–177, 170f–177f chronic fistula and, 178–185, 178f–185f Horizontal fracture of maxillary central incisor, 141–152, 141f–152f Hydroxyapatite, 44

I Ice cream cone technique, 84–87, 84f–87f, 93f Immediate tooth replacement therapy advantages of, 2–3 challenges associated with, 10–11 definition of, 1 delayed tooth replacement therapy versus, 2–3 implant design for, 66–71 interdental papilla loss associated with, 11 for molars alternative strategies, 122–123 description of, 117, 128 protocol for, 3t recession with, 10 side effect of, 10 survival rates for, 2 in type 2 extraction sockets, 77–83, 78f–83f Implant(s) abutment and, interface between, 64 coaxial, 69, 69f connective tissue grafts around, 1 cylindrical, 66 design of, for immediate tooth replacement therapy, 66–71 drifting of, 11 failure of, 137f ideal position of, 25 inverted body-shift design of, 69–71, 70f loading of, 35 narrow-diameter, 34, 70, 94 regular-width, 71 smaller-diameter, 120 spatial position of, 24 straight, 69 tapered, 66 thread design of, 66 thread pitch of, 66 tissue discoloration around, 41 wide-body, 71 wider-diameter, 70, 120 zygomatic, 69 Implant angulation, 28, 122 Implant depth for platform switching, 30, 66 restorative contour affected by, 29–30 shallow, 29 Implant placement delayed. See Delayed tooth replacement therapy. description of, 26, 27f immediate. See Immediate tooth replacement therapy. in molar extraction sockets, 119–122 ridge augmentation with, 93

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Implant positioning restorative contour affected by, 25 restorative emergence profile affected by, 25–26 Implant stability, 119 Implant-abutment interface, 24 Implant-tooth distance, 121, 122f, 123 Impression-making techniques, 134–136 Interdental papilla loss of, with immediate tooth replacement therapy, 11 proximal contact area and, 47–48 Internal resorption lesion large, 153f–157f, 153–158 at maxillary central incisor, 159–163, 159f–163f Inverta implant, 70f Inverted body-shift design implant, 69–71, 70f iShell custom healing abutment with, 55–56, 55f–57f full provisional restoration with, 58–61 illustration of, 46f peri-implant soft tissue and, 222 in provisional restoration fabrication, 153, 166, 180, 188 seating of, 56 socket shape restored using, 109 technique for, 55–61

Molars delayed tooth replacement therapy for, 127–128 extraction sockets, implant placement into, 119–122 immediate tooth replacement therapy for alternative strategies, 122–123 description of, 117, 128 multirooted, 119 second, 119 Mucogingival junction, 101, 102f Mucoperiosteal flaps, 127 Multirooted teeth, tooth extraction for, 118–119

N Narrow-diameter implant, 34 Nealon technique, 134 Nonabsorbable membranes, 84 Nonsurgical tissue sculpting, 8, 9f

O Occlusal overloading, 136, 136f Open tray technique, for impression making, 134 Osseointegration, 36 failure of, 32 Osseous crest, 63

Labial bone plate absence of, 1 mm midfacial recession with, 109–113 blood supply to, 19–20 loss of case study of, 186–194, 186f–194f at maxillary central incisor, 207–216, 207f–216f thickness of, 20 Labial gap distance, 70 Labial ridge, 20–21 Labial tooth position, midfacial recession caused by, 101 Large internal resorption lesion, 153f–157f, 153–158 Lateral excursions, maximum intercuspal position of, 54 Lateral excursive movements, 6 Lithium disilicate veneer restorations, 212

M Maxillary central incisor horizontal fracture of, 141–152, 141f–152f internal resorption lesion at, 159–163, 159f–163f labial plate loss at, 207–216, 207f–216f vertical crown fracture of, 164–169, 164f–169f Maxillary first molar, external resorption lesion at, 217–219, 217f–219f Maximum intercuspal position description of, 6 of lateral excursions, 54 Membranes absorbable, 84 collagen. See Collagen membranes. nonabsorbable, 84 Metal abutment, 65f Metal-ceramic restorations, 64, 108 Metal-ceramic screw-retained restorations, 126 Midfacial recession labial tooth position as cause of, 101 1 mm, with absence of labial bone plate, 109–113 3 mm, 103–108

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P Papilla-sparing incision, 93 PDL. See Periodontal ligament. PEEK. See Polyetheretherketone. Periapical lesions description of, 65 tooth fracture with necrosis and, 195–206, 195f–206f Peri-cementitis, 24 Peri-implant soft tissue horizontal thickness of, 30–32 platform switching effects on, 31 thickness of, 40–42 Periodontal ligament blood supply from, 19 description of, 70 Periodontal phenotype description of, 31–32 thick, 148 thin, 44f Periodontal probes extraction socket management using, 15, 15f illustration of, 15f Platform switching abutment selection in, 64 definition of, 66 description of, 66–68 implant depth for, 30, 66 implant placement affected by, 68 peri-implant soft tissue affected by, 31 supracrestal biologic width, 68, 68f Polyetheretherketone, 48, 51f, 109, 111, 125, 199, 208 Polyvinyl siloxane, 106 Posterior teeth molars. See Molars. multirooted extraction sockets in, 117 Primary flap closure, secondary-intention wound healing versus, 33–34 Prosthetic socket sealing custom healing abutment in, 46 definition of, 46

 Index

L

229

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dual-zone technique with, 48–54 illustration of, 113f iShell. See iShell. provisional crown restoration, 46–48, 47f–48f Provisional restorations bleeding upon removal of, 62 breakage or delamination of, 137–139 cement-retained, 64, 64f, 95, 137 complications with, 139 crown, 46–48, 47f–48f finalization of, 146 healing abutment and, 62 immediate, delayed implant placement with, 88–89 iShell for fabrication of, 153, 166, 180, 188 screw-retained, 64, 64f, 95 seating of, 144 soft tissue sculpting with, 98, 98f subgingival contours of, 135 Proximal contact area, interdental papilla and, 47–48 Punch technique, 89–92, 90f–91f

Index

230

R Regular-width implants, 71 Restorative contour implant angulation effects on, 28 implant depth effects on, 29–30 implant placement effects on, 26, 27f implant position effects on, 25

S Screw-retained metal-ceramic crown, 97, 183, 192, 203 Screw-retained provisional restoration, 64, 64f, 95 Second molars, 119 Secondary-intention wound healing, primary flap closure versus, 33–34 Single-rooted anterior teeth, 21–23 Single-tooth implants, 1 Small beak extraction forceps, 142 Smaller-diameter implants, 120 Socket-shield procedure, 65 Soft tissue sculpting, with provisional restoration, 98, 98f Square teeth, 31 Straight implants, 69 Subcrestal angle correction implant design, 169–170, 198 Subgingival contour, 29 Supracrestal biologic width, 68, 68f Supracrestal gingival fibers, 142

T Tapered implants, 66 Teeth extraction of. See Tooth extraction. morphology of, 31 Thread design, 66 Thread pitch, 66 Tissue discoloration around implants, 41 Tissue maturation, 106 Titanium healing abutment, 106 Tooth extraction atraumatic, 21, 79, 85f, 142, 159, 170, 179 flapless, 19–21 flapped, 19–21

Tarnow-Chu_Index.indd 230

mucogingival junction after, 102f for multirooted teeth, 118–119 single-rooted anterior teeth, 21–23 Tooth fracture with necrosis, periapical lesions and, 195–206, 195f–206f Transmucosal abutment, 30 Triangular teeth, 31 12-degree implant, 69f Type 1 extraction sockets case studies of, 141–185 description of, 12, 13f management of, 19–72 Type 2 extraction sockets after collagen membrane absorption, 87f case studies of, 186–206 description of, 12, 13f ice cream cone technique for, 84–87, 84f–87f, 93f implants in delayed placement of, 84–89 immediate placement of, 77–83, 78f–83f survival rate for, 77 membranes for absorbable, 84 nonabsorbable, 84 subclassification of, 77, 78f–79f Type 3 extraction sockets case studies of, 207–226 description of, 12, 13f management of, 101–114 Type A socket, 120 Type B socket, 120, 124 Type C socket, 120–122, 121f

U Ultrawide implants, 117f, 119, 217 Undercontour, 26

V Vertical crown fracture, of maxillary central incisor, 164–169, 164f–169f

W Wide-body implants, 71 Wider-diameter implants, 120 Wound healing bone plate thickness in, 33 of extraction sockets, 20 gap distance and, 32–37 secondary-intention, primary flap closure versus, 33–34

X Xenografts, 44, 45f, 146

Z Zone of inflammation, 67f Zone of irritation, 67f Zygomatic implants, 69

8/8/19 3:29 PM

Tarnow Chu

The

3  Management of Type 2 Extraction Sockets 4  Management of Type 3 Extraction Sockets 5  Clinical Management of Posterior Teeth 6  Important Considerations in Implant Dentistry 7  Clinical Case Appendix

Single-Tooth Implant

2  Management of Type 1 Extraction Sockets

The

1 History and Rationale for Anterior and Posterior Single-Tooth Implants

A Minimally Invasive Approach for Anterior and Posterior Extraction Sockets

Contents

Single-Tooth Implant

Dennis P. Tarnow, dds Stephen J. Chu, dmd, msd, cdt

A Minimally Invasive Approach for Anterior and Posterior Extraction Sockets

ISBN 978-0-86715-771-0

90000>

9 780867 157710

Chu-Tarnow_coverspread.indd 1

8/13/19 9:31 AM