Contouring posterior bridges

Table of contents :
1.pdf
2.pdf
3.pdf
4.pdf
5.pdf
6.pdf
7.pdf
8.pdf
9.pdf
10.pdf
11.pdf
12.pdf
13.pdf
14.pdf
15.pdf
16.pdf
17.pdf
18.pdf
19.pdf
20.pdf
21.pdf
22.pdf
23.pdf
24.pdf
25.pdf
26.pdf
27.pdf
28.pdf
29.pdf
30.pdf
31.pdf
32 - Copy.pdf
33.pdf
34.pdf
35.pdf
36.pdf
37.pdf
38.pdf
39.pdf
40.pdf
41.pdf
42.pdf
43.pdf
44.pdf
45.pdf
46.pdf
47.pdf
48.pdf
49.pdf
50.pdf
51.pdf
52.pdf
53.pdf
54.pdf
55.pdf
56.pdf
57.pdf
58.pdf
59.pdf
60.pdf
61.pdf
62.pdf
63.pdf
64.pdf
65.pdf
66.pdf
67.pdf
68.pdf
69.pdf
70.pdf
71.pdf
72.pdf
73.pdf
74.pdf
75.pdf
76.pdf
77.pdf
78.pdf
79.pdf
80.pdf
81.pdf
82.pdf
83.pdf
84.pdf
85.pdf
86.pdf
87.pdf
88.pdf
89.pdf
90.pdf
91.pdf
92.pdf
93.pdf
94.pdf
95.pdf
96.pdf
97.pdf
98.pdf
99.pdf
100.pdf
101.pdf
102.pdf
103.pdf
104.pdf
105.pdf
106.pdf
107.pdf
108.pdf
109.pdf
110.pdf
111.pdf
112.pdf
113.pdf
114.pdf
115.pdf
116.pdf
117.pdf
118.pdf

Citation preview

Tech BO Ok Conto1ring Pesterior Bridges

-A I \

"""

~

F --

;

L

(j

id

PTC TechMaster Series

Contouring Posterior Bridges John C. Ness CDT

Dedicated to:

The entire staff of PTC Your efforts and loyalty have allowed us to continue developing and expanding PTC's mission. John would be very proud of you all.

President, CEO

Editors James Ma han CD T Ma rk Larson Illustration Chr isto phe r Cross BA, MA Photography Chr isto phe r Cross BA, MA Design Phillip Ma rash ian Technical Review Tin a Hoy

s developed by This publication was adapted from method John C Ness CD T

-

ITY TRA ININ G CO RPORATIO Copyright © 20 11-2013 PRO DUC TIV in any form or by any means, on may be repr oduc ed or tran smit ted icati publ this of part o ved. reser s All worldwide right info rmat ion storage and retrieval ocopying , recording, scan ning or by any electronic or mechanical, including phot n of Productivity Training Corp orati on. system, with out prio r writ ten perm issio 9 Printed in the USA. Revision 1 - 2013 .03.1 Published by

Productivity Training Corp orat ion 360-A Coc hran e Circle Morgan Hill, CA 95037 • Fax: 408- 776-0145 Phon e: 408-776-0433 • 800-448-8855 .ptcdental.com E-mail: [email protected] • Web: www

-

-

•""' •I

..

•I I

I

Contents I Full Arch Tooth Reference 09 I Jntroductorv, Refc'rc11cc . 15 I Pnrt One I Rough Contouri ng 37 I Pnrt Two I Contouri ng Primary Anatomy 81 I Pnrt "fliree I Contouri ng Secondar y Anatomy 103 I Pnrt Four I Final Contour and QC 111 I Glossn ry

Spedal Notice to Instructors and Students a systematic manner. Please This Tech Guide is designed to assist you in completing this course in l sections and check off follow each step in succession. Do not skip ahead or complete severa everything at once. course where you will be asked It is best to study this course with a partne r. There are areas in the correctly duplicated the to demon strate to anoth er person. Witho ut verification that you have inform ation you can not be sure you under stand. The follow ing ICONS are used in this TechGuide to indicate: Read a specific section of this TechGuide.

Watch the specified PTC System

DVD.

Practical exercise that you will practice by yourself, then demon strate to your instruct or.

Refer to the Ness Teeth ™.

0

6

Cycle 1

Check the boxes as you comple te each task in a cycle.

J>rotluctil'itr l rt1i11i11g ( orpori1tio11

Explanation

Getting Ready

The following abbreviation will be used in this Tech Guide to refer to this course and its parts:

Before you start the CPB Course, be sure you have the following training and study materials:

• CPB: Contourin g Posterior Bridges ~

Course Prerequisites • Simplifying Posterior Dental Anatomy

TechGuide Learning Cycles Repetition creates CERTAINTY. This TechGuide has been designed to be completed in three cycles. You will be using the videos, TechGuide and exercises from the beginning to the end of each cycle. As you go, you will check off and initial the steps, and your instructor will occasionally test you and sign off, too. You will be checked out repeatedly until you can demonstrate comprehen sion of the skills. After completing Cycle 1, start over from Part One and complete Cycle 2 in the same manner. Cycle 3 is recommen ded but optional, at the discretion of your instructor. Don't skip cycle 3 if you do not know the material with 100% certainty.

Instructor: When a student demonstrates with certainty that they know the material, there is no need to complete the next cycle.

1. The PTC CPB DVD, containing: • CPB Part One: Primary Contourin g • CPB Part Two: Occlusal Anatomy • CPB Part Three: Final Contour/S tain and Glaze

2. Ness TeethT"' • A set of large training models of single posterior teeth.

3. CPB Student Kit • This TechGuide • Stones, diamonds, burs and articulating paper

4. TV & DVD player or computer set up and operational S. Pencils, pens, note pad 6. Rubber molds • PU-1 upper operative model for 4-unit posterior bridge with AL-2 lower opposing model. • PL-4 lower operative model for 4-unit posterior bridge with OU-7 upper opposing model.

Note: Mount all models opposing unprepared teeth.

( 011to11ri11g Posterior Bridp,cs

7

Definitions The ability to understand a subject matter and to be able to communicate it with others is primarily dependent on understanding word definitions. The problem with communication is that we assume we understand most words that we hear. But, in fact, many times we unknowingly apply an altered definition, partial definition, or wrong definition. The term "ridge" is a good example.

3. Cycle 3 is used for refinement of any misunderstood words, concepts or procedures. You should understand and be able to clearly communicate the subject to others, and you should be able to apply the fundamentals you learned in cycles 1 and 2 to practical cases.

•

Certainty Drills Posterior Rotational Axis

l'lrtha lower nm mola1Ness Tooth, study and 1hen demonst1at. ? . Ce n11;il honzon:al :me\io·01stal) rotanon;ril a)(iS

3. Cent1vcco-l'nqudl rotation.di 1T N,'.ft'l"L'llu',

Full Arch Tooth lkfcrenct·

~

Mandibular Primary Anatomy

Co11t1111ri11g Po:>tcrior Bridge:;

11

~ Full Arch Tooth Reference Maxillary Secondary Anatomy

-

--

12

Prod11ctil'it1 · Jrnini11g ( orpomtion

•

!utriJd11l/1111

rJ

l11t '

I Hough Contouring

r'j PTC

STEP Mark and contour the mesial and 12 distal triangles. On the buccal surface, draw triangles on the mesial and distal of each tooth. Make each triangle 1.5 mm wide in the gingival area and bring it to a point at the occlusal. (Fig. 1) Use a Speedy separating disc to contour the mesial triangles, rounding the buccal surface into the interproximals. (Fig. 2) Rotate the bridge 180° and with the occlusal facing you, contour the distal triangles. (Fig. 3) Mark and contour the lingual triangles the same way, rounding them into the interproximals. Use the separating disc to individualize the occlusal interproximals of each tooth. In this step you will begin to establish the mesial and distal marginal ridges of the connected teeth. Contour only .5 mm deep. (Fig. 4)

I (~ . ; contour distal triangles

( 011to11ri11g Posll'rior Bridges

25

~ Rough C ontouring

---

J>11rt < l11l'

STEP Contour under the pontic to seat 13 the bridge. On the pontic, use a 301 green stone to contour the tissue contact area to create a sanitary seal. (Fig. 1)

I : I contour pantie

Contour the lingual to the crest of the ridge. Blend the porcelain with the supporting framework. The base of the pontic should be welladapted to the model. (Fig. 2 and 3)

I '" _ contou r lingual to crest of ridge

I

26

.

contour to ridge crest

J>rotf11cti1 •if) • Jrai//i11g rorpomtion

-

/>cir/

< )11iii"/< >u,

Practice the following drill until you understand it and can repeat it without hesitation to your instructor.

Rough Contouring Sequence Practice this drill with a hand piece and real models. Work on one bridge at atime. 1. Read the prescription and sandblast the abutments. 2. Mark and contour the contacts. 3. Mark and contour the marginal ridges. 4. Contour to achieve centric. 5. Mark and contour the interproximal separations. 6. Mark and contour the mesial and distal triangles. 7. Contour under the pontic to seat the bridge. 8. Mark and contour the buccal and lingual heights of contour.

Student Cycle 1 Date _ _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Instructor Cycle 1 Date _ _ _ __

0

5.

Now do the Rough Contouring Exercises on the following pages.

6.

Refer to the previous pages as you do the following steps. Work on one bridge at a time.

7.

Read the prescription and sandblast inside the abutments. 0

8.

0

Cycle 2

0

Cycle 3

Remove the tissue section of the model and the distal contact section. Mark the contact area and adjust it until the margins seat fully. Repeat for the other contact. 0

9.

Cycle 1

Cycle 1

0

Cycle 2

0

Cycle 3

Mark and contour the marginal ridges. 0

Cycle 1

0

Cycle 2

0

Cycle 3

0

Cycle 2

0

Cycle 3

I 0. Contour to achieve centric.

0

28

Cycle 1

J>rod11t ti1•it1• 1r11i11i11g Corpomtio11

f '1irt ( >11t

. rJ I Ro ugh C ontou ring PTC ~

~

11. Mark and contour the interproximal separations.

0

Cycle 1

0

Cycle 2

0 Cycle 3

12. Mark and conto ur the mesial and distal gingival triangles.

0

Cycle 1

0

Cycle 2

0 Cycle 3

13. Replace the tissue section. Conto ur under the pontic to seat the bridge . 0

Cycle 1

0

Cycle 2

0 Cycle 3

14. Mark the buccal and lingual heights of contour.

0 Cycle 1

0

Cycle 2

0 Cycle 3

15. Have your instru ctor check your work. When your instru ctor approves, go on

to the next section.

Stude nt Cycle 1 Date _ _ _ __

Cycle 2 Date._ _ _ __

Cycle 3 Date _ _ __

Cycle 2 Date._ _ _ __

Cycle 3 Date _ _ __

Instru ctor Cycle 1 Date _ _ _ __

nto11ri11~'

Posterior Bridges

29

/>11rt ( >11t '

I Rough C ontouring ~ ' '

Part One: Rough Contouring Practical Exercise Use this copy for Cycle 1. 1. What term describes the teeth that support and retain the bridge? _ _ _ _ _ _ _ _ __

2. What is the term for the unit on a bridge that replaces a missing tooth? _ _ _ _ _ _ __ 3. What term describes the space between the proximal (adjacent) surfaces of two teeth?

4. \!\That is the ridge of enamel that borders the occlusal surface next to another tooth? _ __

5. What term describes the maximum closure of the teeth? 6. What term describes the maximum contour of a surface? ------------7. What is the first step in contouring any case? _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 8. How can you tell when the proximal contacts have been properly contoured?

9. Number the following steps from 1 to 4 in the correct sequence for contouring a bridge: ____ Adjust under the pontic ____ Create interproximal separations ____ Adjust centric occlusion ____ Adjust the proximal contacts Student sign _ _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ __ _ _ __

Instructor sign _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ _ _ _ _ __

( 011to11ri11g Posterior Bridges

31

J>c1r / 011,'

I Rough Contouring rJ PTC ~

~

Part One: Rough Contouring Practical Exercise Use this copy for Cycle 2. 1. In your own words, explain height of contour. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

2. What is the first step in contouring any case? _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 3. Explain the difference between a pontic and an abutment. _ _ _ _ _ _ _ _ _ _ _ __

4. What is the width of the interproxima l triangle at the gingival? 5. In your own words, explain centric occlusion

6. Write two reasons why you would open the interproxima l separations before adjusting under thepontic. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _~

7. In what area do you make the interproxima l separations the deepest? _ _ _ _ _ _ _ __ 8. Draw the interproxima l separations to divide up this bridge into properly proportioned teeth.

Student sign _ _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ _ _ _ _ __

Instructor sign _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ _ _ _ _ __

( 011lo11ri11g Postaior Bridges

33

f Jcm ( >11 ,

Rough C ontouring

r'"j PfC

Part One: Rough Contouring Practical Exercise Use this copy for Cycle 3. 1. What is the first step in contouring any case? _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

2. Describe how you can tell by looking from the mesial and from the occlusal that you have achieved the proper height of contour on a bridge _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

3. Describe the depth of the interproximal separations in all areas (buccal, gingival, etc) _ __

4. Number the following steps from 1 to 4 in the correct sequence for contouring a bridge: ____ Adjust under the pontic ____ Create interproximal separations ____ Adjust centric occlusion ____ Adjust the proximal contacts 5. Draw lines on the buccal and lingual of this overbuilt bridge to indicate the proper heights of contour.

Student sign _ _ _ _ _ __ _ _ _ _ __ __

Date _ _ _ _ _ __

Instructor sign _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ _ _ _ _ __

( 011/011ri11g Poslcnor Brit(i.;cs

35

Part Two

Contouring Primary Anatomy

-- --

--------- -

\ . ]) . ' f"j PTC Contou ring nmary r\ llatomy

J>ort

/ 11·11

Part2: Contouring Primary Anatomy occlusal perime ter

The perimet er of the occlusal surface. The sharp edge where the buccal and lingual surfaces of the tooth meet the occlusal surface. dissectional groove

A groove that divides a posterio r tooth into two distinct parts. A dissectional groove breaks through the occlusal perimeter. primar y plane

On a posterio r tooth, the flat planes at angles of 15 to 30° which make up the basic occlusal, buccal and lingual surfaces. fossa

A rounded or angular depression in the occlusal surface of a posterio r tooth bordere d by the cusp ridges and the occlusal perimeter. occlusal pit

The deepest point of the occlusal fossa. rotatio nal axis

An imagina ry line about which an object can be rotated. I.

38

Practice the following drills until you underst and them and can repeat them without hesitation to your instructor.

ProdlH til'it .1• lnli11i11g ( orporatio11

!'cm / 11·,i I C onto uring Pri ma ry. An ato my . ~

~

Upper Primary Anatomy Using the large illustration on page 10, point out with a bl unt instrument to your partner/coach and name each primary anatomy feature on every tooth. 1. Point out each buccal and lingual dissectional groove. 2. Point out each central dissectional groove. 3. Point out each occlusal primary plane. 4. Point out each buccal and lingual primary plane. 5. Point out each occlusal pit. 6. Outline each fossa .

Lower Primary Anatomy Using the large illustration on page 11, point out with a blunt instrument to your partner/coach and name each primary anatomy feature on every tooth. 1. Point out each buccal and lingual dissectiona l groove. 2. Point out each central dissectional groove. 3. Point out each occlusal primary plane. 4. Point out each buccal and lingua l primary plane. 5. Point out each occlusal pit. 6. Outline each fossa .

Student Cycle 1 Date _ _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Cycle 2 Date_ _ __ _

Cycle 3 Date _ _ __

Instructor Cycle 1 Date _ _ __

2.

Watch the CPB DVD Part Two: "Primary Anatomy". 0

~\ 3.

_

Cycle 1

0

Cycle 2

0

Cycle 3

Read the next section of this Tech Guide, which describes the contouring the dissectional grooves that separate the cusps.

( (l/1/011ri11g Posterior Bridges

39

~ C ontouring Primary. A natomy. ~

/>1111 J i1, •

STEP Mark the 15 grooves.

pits and dissectional

Mark the occlusal pits on your bridge with a pencil. (Fig. 1 in red) Mark the intersections where the buccal and lingual dissectional grooves meet the central groove on the molars and lower second bicuspids. (upper molars shown in purple on Fig. 1) Mark reference lines for the central, buccal and lingual dissectional grooves on all teeth. (Fig. 2)

STEP and contour the marginal 16 Mark ridges. Use a pencil to outline the marginal ridges. I 1,. _ mark the dissectional grooves

Place a #37 inverted cone carbide bur in your high speed handpiece. With the lingual facing you, rotate the bridge counter-clockwise on its vertical axis approximately 45°, then away from you at 20° on its mesio-distal axis. Contour the buccal half of the mesial marginal ridge, cutting deeper at the mesial pit. (Fig. 3) Rotate the bridge on its vertical axis to 45° clockwise and 20° toward you on its horizontal axis. Contour from the mesial pit toward you, forming the lingual half of the marginal ridge. (Fig. 4) Repeat the above rotations and carving action for each mesial marginal ridge on the bridge Rotate the bridge 180° so the buccal is facing you and repeat the procedure for each distal marginal ridge.

40

Prod11cti1•it1• lmi11i11g Corpomtio11

J>c1rt

f11 'iJ

I Contouring Pri mary Ana tom y

rJ PK

ote: The previous step establishes the marginal ridges and mesial and distal pits. Cutting deep at each pit creates the maximum 3-dimensional effect possible for each tooth.

STEP Create the central dissectional 17 grooves on the bicuspids. Note: To properly execute contouring the dissectional grooves on a posterior tooth, each tooth rotation is complete when the groove to be contoured is parallel to the floor. Each stroke will be parallel to the floor and toward you. In the following steps the red arrows are pointing toward the technician. Use the #37 inverted cone carbide bur in your high speed handpiece. Begin with the distal facing you. Rotate the occlusal away from you on its central bucco-lingual axis. Contour from the mesial marginal ridge, pulling parallel to the floor, to the mesial pit. (Fig. 2) Rotate the occlusal toward you and contour from the mesial pit to the crest of the transverse ridge. (Fig. 3)

Co11to11ri11~

Postt:rior Bridges

41

~ Contouring Primary A natomy I />c1r1

/ 111 1

Rotate away from you again and contour from the ridge to the distal pit. (Fig. 1) Rotate toward you again and contour just through the distal marginal ridge. (Fig. 2)

~

f -~· :

rotate away

rotate toward

:"

,

;

i

r·-~-..

':::

.. A

•

I i~. ' tool moves toward technician as tooth rotates

42

Prod11rtil'it1' 1 mi11i11,~ ( orpomtio11

.-

/'int / m

1

C ontouring Primary Anatomy

~

STEP

\j

Create the central dissectional 18 grooves on the molars.

r

i

__ .__,....-:e

As with the premolar, start with the distal facing you. Rotate the tooth away from you on its bucco-lingual axis until the surface to be contoured is parallel to the floor. Contour from the mesial marginal ridge to the mesial pit. (Fig. 1) Rotate the occlusal toward you and contour from the mesial pit to the crest of the cusp ridge. (Fig. 2A) Rotate away from you and contour from the crest of the ridge to the central pit. (Fig. 2B) Rotate toward you and contour from the central pit to the crest of the cusp ridge. (Fig. 3A) Rotate away from you and contour from the cusp ridge to the distal pit. (Fig. 3B) Continue the rotation and contour over and through the distal marginal ridge. (Fig. 4)

Note: In the descriptions that follo w, "occlusal depression" will be used to describe the depressions on the occlusal surface that are not pits, but are created by the intersection of some buccal and lingual grooves with the central dissectional groove. I ·

_

J .._. t

C 011/011ri11g Posterior Bric(~es

contour to the distal pit

contour from distal pit

43

~ Contourin g Primary A natom y

/>1111 111·11

STEP Create the buccal dissection al 19 grooves on the upper molars and the lower 2nd molar. To contour the buccal dissectional grooves on the upper molars, begin with the buccal facing you and rotate the occlusal toward you on its central horizontal axis until the groove to be contoured is parallel to the floor. (Fig. 2) I ·'" / buccal dissectional groove

Contour from the central pit toward the buccal. As you reach the occlusal perimeter (Fig. 3), rotate the occlusal away from you while cutting through the occlusal perimeter and down the buccal surface. (Fig. 3) Curve slightly toward the distal as you end the groove. (Figs. 4)

I ',"· : rotate the occlusal toward you

Apply enough pressure to the handpiece to create a well-defined groove. Hold the handpiece firmly and guide it toward you while you move the bridge.

I 1,..::. ·' con tour th ro ugh the occlusal

I

44

. i contour slightly to distal

Prot!11ctil•itl' I rt1i11i11g, ( orpomtio11

~

J 11"< 1 I Contouring Primary Anatomy PTC

f!t1rt

STEP Create the buccal dissectional 20 grooves on the lower first molar. With the buccal facing you, rotate the occlusal toward you. Contour from the depression at the central dissectional groove just mesial to the central pit toward the occlusal perimeter. (Fig. 2A) As you pass through the occlusal perimeter, rotate the tooth away from you and contour down the buccal surface just through the middle third, curving just slightly to the distal at the end. (Fig. 2B) To contour the disto-buccal groove, start in the distal depression and contour toward the distal at a 45° angle (Fig. 3). Rotate the tooth away from you as you cross through the occlusal perimeter, continuing down the buccal surface and curving slightly toward the distal.

____· · ~

(Figs. 4A and B)

l .~· :. 1 rotate toward you, then away

I .· .!.

_,

disto-buccal groove

I •, . -1 rotate toward you, then away

Co11 to11ri11g Posterior Bridges

45

~ Contouring Primary A nato m y

/>1111

/11,1

STEP Create the lingual dissectiona l 2 1 grooves on the upper molars. On the upper molars, start in the distal depression. Rotate the occlusal toward you, and contour toward the mesial at a 45° angle from the central dissectional groove. (Figs. 1 and 2) Rotate the tooth away from you as you pass through the occlusal perimeter.

upper molar

Make a distinct groove through the occlusal perimeter to completely separate the cusps.

..

......... !&.·..

•

: 1 .

Contour down the lingual surface through the middle third, angling the groove slightly toward the distal at its end. (Figs. 3 and 4)

I:.; _ rotate toward you

••

--

-46

Prod11cti1 •it1• 1mi11i11g ( orpomli1111

~ ~

rJ

f'llrl / 11" Co ntour ing Prim ary A natom y PfC

STEP

Create the lingu al disse ction al 22 groo ves on the lower molars. Starting with the lingual facing you, rotate the tooth towar d you and conto ur from the central pit toward the occlusal perimeter. (Figs. 1 and 2) Rotate the tooth away from you as you conto ur throu gh the occlusal perim eter and down the lingual surface to the midd le third.

I ·, .

lingual dissectional groove

Make a distinct groove throu gh the occlusal perim eter to completely separate the cusps. (Figs. 3 and 4)

I ·,. _ rotate toward you

contour through occlusal perimeter

I.'~· 1

( 011to11ri11g

Posterior Bridp,cs

separate cusps

47

~ C ontou ri ng Primary Anato my I I t1r/ 1

f 11·1 >

STEP Create the lingual dissectional 23 groove on the lower first bicuspid. Starting with the lingual facing you, rotate the occlusal toward you and contour from the mesial pit toward the occlusal perimeter. (Fig. 2)

I ...:

lower fi rst bicuspid

Rotate the occlusal away from you as you contour through the occlusal perimeter and down the lingual surface to the middle third. (Figs. 3 and 4)

---

--

I ,g. _ rotate toward you

--

--

----

i :~. i contour to the middle 113

48

Prod11ctil'itr Tr11i11i11g, Corport1tio11

!'111 I

/

11,1

I C onto ur ing Pri mary Anatomy

~

STEP

Create the lingual dissectional 24 groove on the lower second bicuspids. On the lower second bicuspid, start with the lingual facing you. Rotate the occlusal toward you and contour from the central pit to the occlusal perimeter. I . .:. ; lower second bicuspid

(Fig. 2)

Rotate the occlusal away from you as you contour through the occlusal perimeter down the lingual to the middle third. (Fig. 3) Make a distinct groove through the occlusal perimeter to completely separate the cusps. (Fig. 4)

Check the study model to make sure you have done all steps correctly to this point.

0 Cycle 1

0 Cycle 2

Co11to11ri11g Posterior Bridges

1 .;. :: rotate toward you

0 Cycle 3

49

rJ · ]1 nmary · PrC C, ontounng Anatomy I I >en I 4.

I i1·,1

Practice the following drills until you can perform them without hesitation.

Posterior Rotational Axis With a lower first molar Ness Tooth, study and then demonstrate the three central axes used to manipulate teeth during contouring. 1. Central vertical rotational axis. 2. Central horizontal (mesio-distal) rotational axis. 3. Central bucco-lingual rotational axis.

Bicuspid Central Dissectional Groove With an upper bicuspid Ness Tooth, study the sequence of rotational tooth and tool movements necessary to contour the central dissectional groove. 1. Start on the mesial. 2. Rotate the tooth away from you on its bucco-lingual axis until the groove to be cut is parallel to the floor and in line with your bur. Contour from the mesial marginal ridge to the mesial pit. 3. Rotate the tooth toward you on the same axis until the next groove is aligned with the floor and the instrument. Contour from the pit to the crest of the cusp ridges. 4. Rotate away and contour from the ridge crest to the distal pit. 5. Rotate again and contour from the distal pit to the distal marginal ridge.

50

Prod11cti1•ity fr11i11i11g ( orporntio11

""

l'c1rt ht ,i I C ontourin~ Primary, Anatomy, PK: ~

Molar Central Dissectional Groove

With a lower second molar Ness Tooth, study the sequence of rotational tooth and tool movements necessary to contour the central dissectional groove.

1. Start on the mesial. 2. Rotate the tooth away from you on its bucco-lingual axis until the groove to be cut is parallel to the floor and in line with your instrument. Contour from the mesial marginal ridge to the mesial pit . 3. Rotate the tooth toward you on the same axis until the next groove is aligned with the floor and the instrument. Contour from the pit to the crest of the cusp ridges. 4. Rotate away and contour from the ridge crest to the central pit. 5. Repeat as before to contour to the distal cusp ridges, the distal pit, and the distal marginal ridge.

Buccal and Lingual Dissectional Grooves

With an upper first molar Ness Tooth, study the sequence of rotational tooth and tool movements necessary to contour the buccal and lingual dissectional grooves. 1. Start with the buccal surface facing you. 2. Rotate the tooth on its mesio-distal axis until the groove to be cut is near parallel to the floor and in line with your instrument. Contour from the central pit to the occlusal perimeter. 3. Rotate the tooth away from you until the buccal surface is aligned with the floor and the instrument. Contour through the occlusal perimeter to the midd le 1/ 3. 4. Rotate the tooth 180° on the vertical axis so the lingual faces you . On lowe r molars, start in the central pit. On upper molars, start in the distal pit. 5. Contour the lingual groove as you did the buccal.

( 011to11ri11g Posterior Bridges

51

~ Contouring P riman·. Anatomy. ~

J

! 111r1 /11·,,

Student Cycle 1 Date _ _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Instructor Cycle 1 Date _ _ _ __

5.

Refer to the previous pages as you do the following steps. Work on one bridge at a time.

6.

Mark the dissectional grooves with a pencil.

0 Cycle 1 7.

0 Cycle 3

0 Cycle 2

Contour the buccal and lingual dissectional grooves. 0

9.

0 Cycle 3

Cycle 2

Contour the central dissectional grooves.

0 Cycle 1 8.

0

Cycle 1

0 Cycle 3

0 Cycle 2

Have your instructor check your work. When your instructor approves, go on to the next section. Student Cycle 1 Date _ _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Instructor Cycle 1 Date _ _ _ __

emergence profile

The contour of a tooth or restoration where it emerges from the gingiva. ~#;>~

L~

52

~

10. Read the next section of this Tech Guide, which describes the contouring the

planes of the buccal and lingual surfaces.

Producti1 ·ih lrni11i11g Corporation 1

['i 111 / 11, • I Contouri ng

rJ

Primary Anatomy PTC

STEP

the buccal and lingual pri25 Mark mary planes. With a red pencil, remark the buccal heights of contour you created earlier. Then, hold your pencil parallel to the floor and mark along the buccal and lingual cusps of the adjacent unprepared teeth on the model. (Fig. lA and B) Using the marks you made as a guide, place a dot on each cusp tip to indicate its final position. (Fig. 2) Mark a vertical reference line on the buccal from the cusp tips to the height of contour (middle gingival bulge), for each cusp. Refer to the primary Ness Teeth as a guide. (Fig. 3) Rotate the bridge and repeat on the lingual. (Fig. 4) 1 · ~. _ mark cusp tips on bridge

1 ..

~

buccal vertical reference

- heights of contour

( 011/011ri11g Po ...;terior Brirod11ct il'it1• 1r11i11i11g ( orpomtio11

""'"'

;:

f 'un I H'11r1

I 11, 1 I Con tou r ing Primary Anatomy

~

STEP

Refine the occlusal planes and 34 ridges on the lower first molar. With the buccal facing you, align the diamond with the lingual plane of the mesial marginal ridge. Contour the lingual plane 1, then turn the tooth to align the buccal plane with the diamond and contour plane 2. (Fig. 1) Rotate the bridge so the lingual faces you. Align the diamond with the mesial plane of the mesio-buccal cusp. Contour plane 3. Rotate the tooth and contour the mesial plane of the mesio-lingual cusp 4. (Fig. 2) Rotate the bridge so the buccal faces you. Maintaining the correct alignment, contour planes 5 and 6. (Fig. 3) Rotate the bridge so the lingual faces you. As before, contour planes 7 and 8. (Fig. 4)

I:~. -I

Co11/011ri11g Postcrior Bridges

contour pla nes 7 and 8

65

~ C ontou ring Prima ry An ato my ' f

1 u1

t I 11·, •

With the buccal facing you, contou r planes 9, 10 and 11 . Align the diamo nd with the distal plane of the disto -lingual cusp. Conto ur plane 9, then turn the tooth to align the distal plane of the extra cusp with the diamo nd and conto ur plane 10. (Fig. 1) Next rotate the tooth slightly and align the distal plane of the disto-buccal cusp and conto ur plane 11. (Fig. 2)

I . I contour planes 9 and 10

Rotate the bridge so the lingual faces you and conto ur planes 12, 13 and 14. Align the diamond with the mesial plane of the extra buccal cusp. Conto ur plane 12, then rotate the tooth to align with the buccal plane of the distal marginal ridge and conto ur plane 13. (Fig. 3) Rotate the tooth to align with the lingual plane of the distal marginal ridge and conto ur plane 14. (Fig. 4)

contour plane 11

I :..,. ~

I ,

66

1

contour plane 14

Productil'itv fr11i11i11g. C01pomtio11

i

~

f 't1rt iH ,. Contou ring Primary An atomy PfC

STEP Refine the occlusal planes and 35 ridges of the lower second molar. With the buccal facing you, align the diamond with the lingual plane of the mesial marginal ridge. Contour plane l, then turn the tooth to align the buccal plane with the diamond and contour the buccal plane 2. (Fig. 1) Rotate the bridge so the lingual faces you. Align the diamond with the mesial plane of the mesio-buccal cusp. Contour plane 3. Rotate the tooth and contour the mesial plane 4 of the mesio-lingual cusp. (Fig. 2) Rotate the bridge so the buccal faces you. Keeping the diamond aligned with the plane, contour the distal plane 5 of the mesio-lingual cusp. Realign and contour the distal plane 6 of the mesio-buccal cusp. (Fig. 3) Rotate the bridge so the lingual faces you. Contour the mesial plane 7 of the disto-buccal cusp. Rotate the tooth, align and contour the mesial plane 8 of the disto-lingual cusp. (Fig. 4)

l ( 0 11to11ri11g

Posterior Bridges

~- I

distal cusp mesial planes

67

. ] . ~ ~ PrC Contounng Jnmary An atom y

/'1111 / 11·(1

With the buccal facing you, align the diamond with the distal plane of the disto-lingual cusp. Contour plane 9, then turn the tooth to contour the distal plane 10 of the disto-buccal cusp. (Fig. 1)

Rotate the bridge so the lingual faces you. Contour the buccal plane 11 of the distal marginal ridge. Rotate the tooth and contour the lingual plane 12 of the distal marginal ridge plane. I· .

I

distal cusp distal planes

(Fig. 2)

Check the study model and Ness teeth to make sure you have done all steps correctly to this point.

-

I',;. _ dista l marginal ridge

-

-

-

--

68

flroil11cti1 ·itv '/ mi11i11g Corporation

J>t1rt / H

,1

I Contouring Priman. Anatomy. '

~

STEP

36 Check lateral movements. Re-mark the centric stops and the cusp tips so that you do not inadvertently grind them away. (Fig. 1)

Check lateral movement by shifting the upper member of the articulator to the left and right. ote how the lower cuspid slides down the disto-lingual of the upper cuspid, forcing the upper and lower posterior teeth apart. (Fig. 2)

I:-: . / mark centric stops and cusp tips

If the cusps or ridges on the upper and lower posterior teeth interfere with each other, use a PTC 301 or 313 green stone to remove the interference. Be careful not to remove centric stops or cusp tips. (Fig. 3) Place a PTC posterior diamond in your handpiece and refine the mesial and distal slopes of the working cusps at approximately 30° to the occlusal surface. Do not reduce the cusp tips. (Fig. 4)

1

check lateral movement

i... Co11to11ri11g Posterior

Britf.~cs

69

~ C ontouring Primary Anatomy

/llll 1

I 11·, 1

STEP

3 7 Examine the bridge.

You have now contoured the contact areas, the marginal ridges, the buccal and lingual surfaces, and the basic shapes of the cusps. The bridge you are contouring should look like the example in figure 1. If it does not, review the steps to this point and locate your error.

If necessary, selectively contour any areas needed to achieve the correct shape. Compare the buccal surfaces on the bridge with those on the adjacent unprepared teeth. (Fig. 2) Contour if necessary to adjust the angles of the cusps on the bridge so that they correspond with those of the natural teeth. (Fig. 3)

1 ·.c _ minor corrections

Have your supervisor or instructor check your bridge for accuracy.

0

Cycle 1

0

Cycle 2

0

Cycle 3

-

70

l'roc/11ctil'itr lrni11i11g ( orporatio11

J>c1n / 11

(1

I Co ntouring Primary .An.1tomy

"" PTC

19. Study the following drills until you can perform them without hesitation.

Triple Axis Plane Alignme nt With a Ness tooth upper bicuspid Ness Tooth, study the 3 rotational movements necessary to position the occlusal plane being contoured parallel to the fioor and aligned with the instrument. 1. With the occlusal up, rotate the tooth on its central bucco-lingual axis until the buccal and lingual edges of the plane are parallel to the floor. 2. While keeping the buccal and lingual edges parallel to the floor, rotate the tooth on its central horizontal axis until the mesial and distal edges are also parallel to the floor. The plane will now be parallel to the floor. 3. Align the plane with your instrument by rotating the tooth on its vertical axis. When the plane is properly aligned with the tool, the tool will align perfectly with the central dissectional groove.

Upper Bicuspid - Occlusal Plane Fundamental Contouring With an upper bicuspid primary Ness Tooth, study and demonstrate the occlusal plane contouring sequence. This is the fundamenta l procedure for contouring all occlusal primary planes. 1. Using the triple axis plane alignment procedure, rotate the tooth to position plane #1 parallel to the floor. Contour the plane toward you. 2. Rotate the tooth until plane #2 is parallel to the floor. Contour toward you as in the previous step. 3. Rotate the tooth 180° and align plane #3 parallel to the floor. Contour planes #3 and #4 as before. 4. Rotate the tooth 180°. Contour plane #5 and #6, then rotate the tooth 180° and contour plane #7 and #8.

( 011to11ri11g

Posterior Bridges

71

~ to u n.n g ]J'nm ary A natom y r.I PTC Con

J>11r1

I 11 ,,

Upper Molar Primary Plane Contour ing With an upper molar primary Ness Tooth, study and demonstrate the occlusal plane contouring sequence. The upper molars follow the same basic contouring fundamentals as the upper bicuspid . 1. Start at the mesial marginal ridge. Align the mesio-buccal plane parallel to the floor and contour plane 1. 2. Rotate the tooth toward you to align the mesio-lingual plane. Contour plane 2, then rotate the tooth 180° to planes 3 and 4. 3. Contour the remaining planes in pairs, buccal/ lingual and lingual/ buccal. Note: Because the mesio-l ingual cusp has 2 extra planes, planes 9, 10, and 11 are contoured on one rotation, then planes 12, 13, and 14 are contoured on the next.

Lower 2nd Bicuspid Primary Plane Contour ing With a lower second bicuspid primary Ness Tooth, study and demonstrate the occlusal plane contouring sequence. The lower bicuspids follow the same basic contouring fundamenta ls as the upper bicuspid. 1. Align the plane farthest away from you flat to the floor, contouring the plane, rotate the tooth toward you to align flat to the floor, and contour the next plane. 2. Rotate 180° to the next set of planes. Contour the remaining planes in pairs, buccal/ lingual and lingual/ buccal. Note: Because the lower second bicuspid has an ext ra cus p, planes 3, 4, and 5 are contoured on one rotation, then planes 6, 7, and 8 are contoured on the next .

Lower 1st Molar Primary Plane Contour ing With alower first molar primary Ness Tooth, study and demonstrate the occlusal plane contouring sequence. The lower molars follow the same basic contouring fundamenta ls as the upper bicuspid . 1. Start on the mes ial. Align the plane farthest from you flat to the floor. Contour, rotate and contour. 2. Rotate 180° to the next set of planes. Contour the remaining planes in pairs, buccal/ lingual and lingual/ bucca l. Note: Because the lower first molar has an extra cusp, planes 9, 10, and 11 are contoured on one rotation, then planes 12, 13, and 14 are contoured on the next.

72

flrod11cti1 ·it1 1rai11i11g ( orpomtio11 1

l'ci! t I 11 ,1 I C ontouri ng P rimarv. Anatom y, ~

~

Prima ry Anato my Conto uring Sequence Practice this drill with contouring instruments and real models. Work one bridge at atime. 1. Mark and contour the dissectional grooves. 2. Mark and contour the buccal and lingual primary planes. 3. Contour the emergence profile. 4. Adjust the length of the non-functional cusps. 5. Refine the occlusal planes. 6. Examine the bridge.

Studen t Cycle 1 Date _ _ _ __

~

Cycle 2 Date_ _ _ _ __

Cycle 3 Date _ _ __

Cycle 2 Date_ _ _ _ __

Cycle 3 Date _ _ __

!::c·

~··~ ...•

·;.

•..

l r~, ,L - -

Instruc tor

...

Cycle 1 Date _ _ _ __

0

20. Do the Primary Contou ring Exercises on the following pages. 21. Refer to the previous pages as you do the following steps.

22. Contou r to establish the occlusal primary planes. For assistance, refer to the Ness Teeth ~ or the large graphics in the Tooth Reference. 0

Cycle 1

0 Cycle 2

0 Cycle 3

23. Have your instruct or check your work. When your instruct or approves, go on to the next section. Studen t Cycle 1 Date _ _ _ __

Cycle 2 Date._ _ _ __

Cycle 3 Date _ _ __

Cycle 2 Date_ _ _ _ __

Cycle 3 Date _ _ __

Instruc tor Cycle 1 Date _ _ _ __

( 011/011ri11g Posterior Bridges

73

I 'en 1

/ 11,'

~

. p . C ontourmg nmary Anatomy

PrC

Part Two: Primary Contouring Practical Exercise Use this copy for Cycle 1. 1. What term describes the outline of the occlusal surface?

--------------

2. What is the term for the grooves that separate the cusps? 3. What is the imaginary line about which a tooth can be rotated into the correct position for

4. What are the depressions on the occlusal surface that are bordered by the ridges and the occlusal perimeter?------------------------------5. What term describes the profile of the tooth near the margin as it emerges from the gingiva?

6. What are the flat planes that shape the primary anatomy of the teeth? _ _ _ _ _ _ _ __ 7. What is the deepest point of the fossa? _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 8. Name the five anatomical features that we need to establish when contouring the primary anat-

9. Imagine the teeth below in cross-section. With a pencil, draw a dot representing the pits on each tooth. Then draw a line showing the relative depth of the dissectional grooves. Here's an example of how it would look on a lower bicuspid:

Student sign _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ _ _ _ _ __

Instructor sign _ _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ _ _ _ _ __

( 011/011ri11g Posterior Brid,~cs

75

J>un / mi I Contouring Primary Anatomy

rJ PrC

Part Two: Primary Contouring Practical Exercise Use this copy for Cycle 2. 1. In your own words, define the emergence profile._________________

2. In your own words, define the primary planes.

3. In your own words, define a dissectional groove. _________________

4. Name the five anatomical features that we need to establish when contouring the primary anat-

omy _________________________________

~

5. On each tooth below, draw the dissectional grooves. Then draw lines separating each primary plane. The upp er first bicuspid is done for you .

••

••

•

I

I

•

•

•

\

Student sign _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ _ _ _ _ __

Instructor sign _ _ _ _ _ _ _ _ _ _ _ _ _ __

Date _ _ _ _ _ __

Co11/011ri11g Posterior Bridges

77

rJ

f 'u1·1 / 11 ,, I C ontouring Primary A natomy PfC

Part Two: Primary Contouring Practical Exercise Use this copy for Cycle 3. 1.

ame the five anatomical features that we need to establish when contouring the primary anat-

2. In your own words, describe a fossa.

3. On each tooth below, draw the pits and the extra intersection where the dissectional grooves meet. Then draw the dissectional grooves and outline each primary plane. Finally, number the planes in the order they would be contoured. The upper first bicuspid is done for you.

(

m1/011ri11s~

Posterior Hridgcs

79

- - - - - - - - - - - --

----

--------

~--------

. 11 · , l"J PfC Cont ounn g nmar y Anat omy

80

1

/>11r1

/11 1 >

I

-

\

-

_ _ __ Stude nt sign _ _ _ _ _ _ _ _ _ _ _ _ _ _

Date _ _ __ _ _ __

_ _ __ Instru ctor sign _ _ _ _ _ _ _ _ _ _ _ _ _

Date _ _ _ _ __ _ _ _

Jlrod11cti1'il\' 1mi11i11g ( orpomtio11

-

..

Part Three

Contouring Secondary Anatomy

~ C ontouring Secondary Anat o my

/>11rl Jiu«,

Part3: contouring Secondary Anatomy 1.

Watch the CPB DVD Part Three: "Final Contouring/Stain and Glaze". 0

2.

Cycle 1

0

Cycle 2

0

Cycle 3

Study the following drills until you can perform them without hesitation. secondary groove

A curving groove that forms one side of an occlusal ridge, in the shape of a lazy "S". A secondary groove does not break through the occlusal perimeter.

r-

Upper Secondary Anatomy

With a blunt instrument, point out and name to another person each secondary anatomy feature on every tooth. 1. Start in the pit and trace every secondary groove on each tooth on the illustration. 2. Start in the pit and trace every secondary groove on each upper Ness Tooth .

Lower Secondary Anatomy

With a blunt instrument, point out and name to another person each secondary anatomy feature on every tooth. 1. Start in the pit and trace every secondary groove on each tooth on the illustration. 2. Start in the pit and trace every secondary groove on each lower Ness Tooth.

-

....

82

Prod11ctil'it1• ] r11i11i11g ( orporation

/'c1r/ /i 1rll· C on touring Seconda ry Anato m y

~

Student Cycle 1 Date _ _ _ __

Cycle 2 Date_ __ _ __

Cycle 3 Date _ _ __

Cycle 2 Date_ _ _ _ __

Cycle 3 Date _ _ __

Instructor Cycle 1 Date _ _ _ __

3.

Read the next section of this Tech Guide, which describes the fundamentals of contouring secondary anatomy.

( 011/011ri11g Posterior Bridges

83

~ Contourin g Second ary Anatomy I />11r/

l/1rct·

Secondary Groove Contouring Fundamentals In the next series of steps we will deal with the creation of secondary grooves. You can practice these movements on a block of wax and on the large secondary Ness Teeth™.

I ·,.

groove depth

Secondary anatomy grooves are very shallow. The three dimensional look of the natural occlusal surface of posterior teeth comes from the primary planes and the overall depth of each fossa and not how deep the secondary grooves are contoured. There are four secondary groove contouring fundamentals: 1. Secondary grooves go from deep in the pit to shallow at the cusp tip. (Fig. 1) 2. The centerline or axis of the groove; that is, the direction of the groove. (Fig. 2)

I ~ . .:. groove axis/centerline

3. The instrument's alignment with the centerline axis. It is important to keep the instrument aligned with the groove being contoured so you create a consistent "V" shaped depression along the entire length of the groove. If the instrument is rotated left or right, the groove will be undercut. In that case, it would not appear natural and would be difficult to polish. (Fig. 3)

-----

I ,\:.. ' instrument/groove alignment

84

Prod11cti1·itr 1r11i11i11g ( orpomti1111

fJt1rl

llrret 1 Co nt ou rin g St'co nd ar y

An ato my

4. The tec hn ici an 's co nt ro l of th e in str um en t an d th e to ot h be in g co nt ou re d. The technician rotates the to ot h to align with th e di re cti on of th e groove being contoured, th en draws th e tool toward themselves along this an gle. The technician will also rotate the to ot h bo th clockwise an d counterclock wise du rin g the cutting stroke to achieve the "S" shape of each se co nd ary groove . (Fig. 1)

econ da ry grooves flow eit her left or right from th eir sta rt point. W he n creating a right flowing groove th e to ot h is bein g rotated slightly counter clockwise as the in str um en t is being drawn towards yo u slightly clo ckwise. As the groove fi nis hes the mo ve me nt is reversed; th at is, to ot h clo ckwise an d in str um en t counterclockwise. (Fig. 1) A left flowing groove has th e ex act opposite mo vements. In summary, th e technici an applies these four fun damental concepts to create th e secondary an ato my. The technician draws th e in str um en t tow ard himself, cutting from deep to shallow, ' hil e simultaneously ro tating th e to ot h an d ins tru me nt in th e appr opriate clockwise an d co un terclockwise directio ns so th at the bu r can reate the flowing organic shape of th e secondary groove.

::J Cycle 1

0

Cycle 2

0

Cycle 3

( 0 11to11ri112 Po ste rio r Br idg es

85

~

L

rJ . . Se(Oll . dary A natomy PrC Contouring 4.

l'.1rl

ii li't t

Study the following drill until you can perform it without hesitation.

Secondary Groove Contouring Fundamentals Study the four fundamental concepts used to contour the secondary grooves. Then contour a series of grooves in an old crown with your #35 bur utilizing these four principles.

1. Control the depth of the groove. The simultaneous pulling of the instrument and the rotation of the surface being contoured enables the deep-to-shallow depth control. 2. Identify the groove axis. 3. Align the instrument with the groove axis. 4. Control the instrument and the surface being contoured.

Student Cycle 1 Date _ _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Cycle 2 Date_ _ _ __

Cycle 3 Date _ _ __

Instructor Cycle 1 Date _ _ _ __

/ijjt2~ s.

86

Read the next section of this Tech Guide, which describes how to contour the secondary grooves.

,,

Protl11ctil'it\.' lrni11i1w ( orj>omtio11

-

' l '11r/ I /!rt'