composites in conservative dentistry for under graduate in bds amrita school of dentistry kochi oedipally Ernakulam , Secrets the college wont teach you .

1. Tooth Preparation for
Composites
ABIMOL DAVIS
AKASH K.S.
SHERIN THOMAS
SREE GOVIND
THIRD YEAR BDS
1

2. Contents
 What is Tooth Preparation?
 What are Composites?
 Advantages & Disadvantages of Composites
 Indications & Contraindications for Composites
 Class I
 Clinical technique for Class I Direct Composite Restorations
 Small to Moderate Class I Composite Restorations
 Moderate to Large Class I Composite Restorations
 Class II
 Clinical technique for Class II Direct Composite Restorations
 Small Class II Composite Restorations
 Conservative Design
 Box-only Design
 Slot Design
 Moderate to Large Class II Composite Restorations
2
• Class III
Lingual vs Facial Approach
Initial Tooth Preparation
Final Tooth Preparation
• Class IV
Conventional Design
Bevelled Design
Modified Preparation
• Class V
• Class VI
• Pit and Fissure Sealants
Indications
Clinical Technique
• Conclusion
• References

3. What is Tooth Preparation?
Tooth preparation is defined as the mechanical alteration of
a defective, injured or diseased tooth such that placement
of restorative material re-establishes normal form and
function, including aesthetic corrections, where indicated.
(Theodore M. Roberson, Sturdevant’s Art and Science of
Operative Dentistry, Fifth Edition, 2009)
3

4. What are Composites?
Composites are tooth-coloured materials that are used in
almost all types and sizes of restorations. They are esthetic
restorations that are bonded to the tooth structure and
today enjoy universal clinical application.
(Theodore M. Roberson, Sturdevant’s Art and Science of
Operative Dentistry, Fifth Edition, 2009)
4

5. Advantages of Composites
Aesthetics
Bond to tooth
structure
Insulative
Used almost
universally
Conservative of
tooth structure
removal
5

6. Disadvantages of Composites
Time-
consuming
Costly
Insertion
difficult
May have
gap
formation
More
occlusal
wear
Technique
sensitive
6

7. Indications for Composites
Temporary
restorations
Core
buildups
Periodontal
splinting
Sealants
Class I-VI
restorations
Veneers
Cements
7

8. Contraindications for Composites
High caries
incidence
Poor oral
hygiene
Teeth with
occlusal
stress
Isolation
difficulties
Patient
allergic
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9. CLASS I
9

10. Clinical Technique for Class I Direct
Composite Restorations
The tooth preparation include:
 1. creating access to the faulty structure
 2. removal of faulty structures (caries, defective
restoration, and base material, if present)
 3. creating convenience form for the restoration.
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11. I. Small to Moderate Class I Composite
restorations
Cavity Design: Less specific,
scooped-out appearance without
uniform or flat pulpal or axial
walls.
Clinical Technique
1. Minimally invasive tooth
preparations.
2. Prepared with a small round or
elongated pear diamond or bur
with round features. The initial
pulpal depth is approx. 0.2m
inside the DEJ.
11

12. II. Moderate to Large Class I Direct
Composite Restorations
Cavity Design
1. Will typically feature flat walls that are
perpendicular to occlusal forces.
2. If the occlusal portion of the restoration
is expected to be extensive, elongated pear
cutting instruments with round features
are preferred because they result in strong,
90 degree cavosurface margins.
12

13. II. Moderate to Large Class I Direct
Composite Restorations: Technique
Step 1: The tooth is entered in the area most affected by
caries, with bur positioned parallel to the long axis.
 Step 2: The pulpal floor is prepared to an initial depth that
is approx., 0.2mm internal to the DEJ.
 Step 3: Extensions into marginal ridges should result in at
least 1.5mm of remaining tooth structure for premolars and
2mm for molars.
 Step 4: If extension is required toward the cusp tips, depth
of 0.2mm inside the DEJ is maintained and pulpal floor rises
occlusally.
13

14. 14

15. CLASS II
15

16. Clinical Technique for Class II Direct
Composite Restorations
The tooth preparation include:
 1. creating access to the faulty
structure
 2. removal of faulty structures
(caries, defective restoration,
and base material, if present)
 3. creating convenience form
for the restoration.
16

17. 17
Conservative
Design
Box-only
Design
Slot Design
I. Small Class II Direct Composite
Restorations

18. 1. Conservative Design
Less specific in form, scooped-out appearance without uniform or flat
pulpal or axial walls.
Clinical Technique
1. A small round bur with round features may be used.
2. The pulpal and axial depths are dictated only by the depth of the
lesion.
3. The proximal extensions are dictated only by the extent of lesion.
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19. 2. Box-only Design
Here proximal surface is defective, with no lesions on the occlusal
surface.
 Clinical Technique
1. a proximal box is prepared with a small elongated pear or
round instrument, held parallel to the long axis of the tooth crown.
2. the instrument is extended through the marginal ridge in a
gingival direction.
3. no bevelling or secondary retention is indicated.
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20. 3. Slot Design
Access to the proximal lesion can be obtained from either a facial or lingual
direction rather than through the marginal ridge in a gingival direction.
 Clinical technique
1. A small round diamond or bur is used to gain access to the lesion.
3. Preparation is extended occlusally, facially and gingivally.
4. Occlusal, facial and gingival cavosurface margins are 90 degrees or greater.
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21. Moderate to Large Class II Direct
Composite Restorations
Occlusal step
 Step 1: A No 330 or No 245 shaped diamond or bur is
used to enter the pit parallelly next to the carious
proximal surface.
 Step 2: Pulpal floor is prepared with depth 0.2mm
inside the DEJ.
 Step 3: Occlusal extension towards proximal surface
is prepared as conservatively as possible.
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22. Moderate to Large Class II Direct
Composite Restorations (Contd..)
Proximal box: Determined by: extent of the caries lesion and amount of
old restorative material (if any).
Clinical technique:
 1. Proximal ditch cut is initiated with the instrument held over the DEJ
to create a gingivally directed cut that is 0.2mm inside the DEJ.
 2. Gingival floor is prepared flat with an 90 degree cavosurface margin.
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23. 23
1 4
11
3
5
6
7
8
9
10
2

24. What are Bevels?
Bevels are the “flexible extensions” of the
cavity preparation, allowing the inclusion of
surface defects, supplementary grooves, or
other areas of the tooth surface.
(Marzouk)
24

25. CLASS III
25

26. Class III Direct Composite Directions
The tooth preparation include:
 1. creating access to the faulty structure
 2. removal of faulty structures (caries, defective
restoration, and base material, if present)
 3. creating convenience form for the restoration.
26

27. Tooth Preparation
 1. Lingual vs Facial approach
 2. Outline form
 3. Initial tooth preparation
 4. Final tooth preparation
27

28. Lingual vs Facial approach: Lingual Approach
 When a proximal surface of an anterior tooth is to be restored.
 Indications:
1. the facial enamel is conserved for enhanced aesthetics.
2. shade matching of the composite is less critical.
3. discoloration or deterioration of the restoration is less visible.
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29. 29

30. Lingual vs Facial approach: Facial Approach
 This approach is always taken only after ruling out the clinical
feasibility of the lingual approach.
 Indications
1. the caries lesion is positioned facially, and facial access would
significantly conserve the tooth structure.
2. a faulty restoration that originally was placed from the facial
approach needs to be replaced.
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31. 31

32. Initial tooth preparation
 Outline form: Initiated from a lingual approach
by using a round carbide bur or diamond
instrument.
 Scooped or concave preparation design.
 Initial axial wall depth of 0.2mm into dentin.
 If the preparation outline extends gingivally,
gingival floor should form cavosurface margin of
90 degrees.
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Large Class III preparation

33. Final tooth preparation
 Steps include:
1. removal of infected dentin
2. pulp protection
3. bevel placement on accessible enamel margins
4. final procedures of cleaning and inspecting.
33

34. 34

35. Clinical Technique
Bevel is prepared by creating a 45 degree
angle to the external surface and to a
width of 0.5-2.0 mm.
35

36. Bevel in Class III 36

37. 37

38. CLASS IV
38

39. 39
Conventional Bevelled
Modified
Types of Class IV Preparation

40. 1. Conventional Preparation
 This has minimal Class IV clinical application, however,
except in areas that have margins located on root
surfaces.
 Few indications except for any portion of the restoration
extending onto the root.
40

41. 2. Bevelled Conventional Preparation
 Large proximal areas & incisal surface of an
anterior tooth.
 Outline form: walls perpendicular or parallel to
long axis of tooth by round-carbide bur or
diamond instrument.
 Initial axial wall depth at 0.5mm into dentin.
 Bevel is prepared at 45 degrees to external tooth
surface.
41
Large Class IV composite
restoration

42. 3. Modified Preparation
 It is indicated for smaller Class IV preparations.
 Little or no initial tooth preparation is indicated.
 Cavosurface margins are prepared with bevelled or
flared configurations.
 Axial depth is no deeper than 0.2mm inside the DEJ.
42

43. Bevel in Class IV 43

44. 44

45. CLASS V
45

46. Class V Direct Composite Restorations
 A tapered fissure carbide bur (No. 271) or similarly
shaped diamond is used.
 External preparation walls of a class V preparation are
visible when viewed from a facial position.
 Bevel on enamel margin is with a flame-shaped or
diamond round instrument, 45 degrees to tooth surface.
46

47. 47

48. CLASS VI
48

49. Tooth Preparation for Class VI
Composite Restorations
 Small faulty developmental pit located on a cusp tip.
 Typically as small in diameter and as shallow in depth.
 Faulty pit is entered with a small round bur.
 Visual examination and probing with an explorer show fault is
limited to enamel because enamel in this area is quite thick.
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50. PIT & FISSURE SEALANTS
50

51. Indications
 Pits and fissures result from incomplete coalescence of
enamel and are prone to caries.
 These areas are sealed using low-viscosity fluid resin.
 Sealants may be indicated for either preventive or
therapeutic uses.
51

52. Clinical Technique
 The tooth is isolated by a rubber dam or cotton rolls.
 Liquid acid etchant – on occlusal surface with applicator tip for
about 30 seconds.
 Tooth is rinsed with water for 20 secs – lightly frosted appearance.
 Self-cured sealant is mixed and applied with a small applicator.
 After polymerization of sealant, rubber dam is removed.
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53. Conclusion
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54. References
1. Sturdevant’s Art and Science of Operative Dentistry: International
Edition; Theodore M. Roberson, Harald O. Heymann, Edward J. Swift
Jr.; Fifth Edition, 2009
2. Sturdevant’s Art and Science of Operative Dentistry: South Asia
Edition; Harald O. Heymann, Edward J. Swift Jr., Andre V Ritter, V
Gopikrishna
3. Clinical Operative Dentistry by Ramya Raghu
4. Case Reports for Class I, Class II and Class IV preparations [Internet]
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