The presentation depicts in a very simplified manner the steps of cavity preparation and restoration of class 3 and class 5 composite restoration. It is well supported with illustrations that further provide a better understanding of the topic.

1. CAVITY PREPARATION
FOR
COMPOSITES
CLASS III
AND
CLASS V

2. CONTENTS
1. Introduction.
2. Indications for Composite Resin Restorations.
3. Contraindications.
4. Advantages.
5. Disadvantages.
6. Clinical Techniques for Class III Direct Composite Restorations.
 Initial Clinical Procedures.
 Tooth Preparation.
 Restorative Technique.
7. Class V Direct Composite Restorations.
 Initial clinical Procedures.
 Tooth Preparation.
 Restorative Technique.

3. INTRODUCTION
“Composite Resin” is a three dimensional combination of two or
more chemically different materials with a distinct interphase between
them.
Basically, composite resins consist of a resin matrix reinforced by
means of fillers.
In order to provide interfacial bonding between these two chemically
different materials, a silane coupling agent is present.
To control the polymerization reaction, activators, initiators and
inhibitors are incorporated.

4. INDICATIONS FOR COMPOSITE RESIN RESTORATIONS
 Most class III cavities are restored with composite resins as they restore optimal
esthetics.
 Class V cavities in esthetically important areas like the anterior region are also
restored with composite resins.
 Class III and class V direct composite restorations are mainly indicated in the
restoration of carious lesions.
 Many Class V restorations that are in esthetically prominent areas also are
appropriately restored with composite or other tooth-colored materials.
 Composites perform best when all margins of the tooth preparation are in
enamel.

5. Class V composite
restoration
Class III composite
restoration
BEFORE AFTER
BEFORE AFTER

6. CONTRAINDICATIONS
• The main contraindication for use of composite for Class III and V restorations is an
operating area that cannot be adequately isolated.
• Class V restorations also may have their durability compromised when the
restoration extends onto the root surface (no marginal enamel).
• Any extension onto the root surface requires the most meticulous efforts of the
operator to best ensure a successful, long lasting restoration.
• Class V restorations in areas that are not esthetically critical.

7. ADVANTAGES
• Esthetic.
• Conservative in tooth structure removal.
• Less complex while preparing the tooth.
• Almost universally accepted.
• Repairable.
• Insulating, having low thermal conductivity.
• Decreased micro leakage.
• Increased strength.
• Good retention.
• Minimal interfacial staining.

8. DISADVANTAGES
• More difficult, time consuming and costly.
• More technique sensitive.
• May exhibit greater occlusal wear in areas of high occlusal stress.
• Insertion is more difficult.
• Establishing proximal contacts, axial contours and embrasures is more
difficult.
• Proper technique is mandatory in the placement of etchant, primer and
adhesive on the tooth structure.
• Finishing and polishing procedures are more complex.

9. CLINICAL TECHNIQUES FOR CLASS III
DIRECT COMPOSITE RESTORATIONS
Class III restorations are done on the proximal surfaces of anterior teeth, which do
not involve the incisal angles.
 Initial clinical procedures:
 Anesthesia is necessary for patient comfort and helps decrease salivary flow during
the procedure.
 Occlusal assessments must be made to determine tooth preparation design.
 Composite shade must be selected before the tooth dehydrates.
 The area must be isolated to permit effective bonding.
Composite shade guide

10. TOOTH PREPARATION
Tooth preparation for class III direct composite restoration involves:
1) Obtaining access to the defect (caries, fracture).
2) Removing faulty structures (caries, defective dentin, defective
restoration).
3) Creating convenience form for the restoration.
Lingual approach is preferred for the following reasons:
• Facial enamel is conserved for enhanced esthetics.
• Unsupported facial enamel may be preserved for bonding.
• Color matching is not so critical.

11. Depending on the extent of the preparation to be restored, there are three
designs:
Conventional.
Beveled conventional.
Modified.
 Conventional preparation:
• Cavity preparation is done using round bur from lingual approach.
• The cutting instrument is directed perpendicular to enamel surface.
• Initial opening is made close to the adjacent tooth.
• Incorrect entry overextends the lingual outline.
• The same bur or diamond is used to enlarge opening for caries removal.

12. Beginning class III tooth
preparation(lingual):
A. Bur held perpendicular to
enamel surface and initial
opening made close to
adjacent tooth at
incisogingival level of
caries.
B. Contact angle of entry is
parallel to enamel rods on
mesiolingual angle of tooth.
C. Incorrect entry overextends
the lingual outline.
D. Same bur used to enlarge
opening for caries removal and
convenience form while
establishing initial axial wall
depth.

13. Many class III preparations are done to an initial axial wall depth of 0.2mm into
dentin.
Ideal initial axial wall preparation depth.
A: Incisogingival section showing axial wall 0.2mm into dentin.
B: Faciolingual section showing facial extension and axial wall following the contour of
tooth.

14. Class III tooth preparation for a
lesion entirely on root surface.
A. Mesiodistal longitudinal
section illustrating a carious
lesion.
B. Initial tooth preparation.
C. Tooth preparation with
infected caries dentin removed.
D. Retention grooves shown in
longitudinal section.
Transverse section through
plane cd illustrates contour of
the axial wall and direction of
facial and lingual walls.
E. Preparing the retention form to
complete the tooth preparation.
A B C
D
E
c------------d
Lingual

15. RESTORATIVE TECHNIQUE
 Matrix Application.
 Placement of the Adhesive.
 Insertion and Light activation of the composite.
 Contouring and polishing of the composite.
A B
C D
Finishing and polishing:
A. Flame shaped finishing
bur removing excess and
contouring.
B & C. Rubber polishing
point (B) and aluminium
oxide polishing point (C) for
final polishing.
D. Completed restoration.

16. CLASS V DIRECT COMPOSITE RESTORATIONS
Class V restorations are done on the gingival third of facial and lingual surfaces of
all teeth.
 Initial clinical procedures:
 Occlusal evaluation not required for class V restorations.
 During shade selection, it must be remembered that tooth is darker and more
opaque in the cervical third.
 Isolation may be achieved by rubber dam or no. 212 retainer.
← Class V carious lesion

17. TOOTH PREPARATION
• After the usual preliminary procedures, the initial tooth preparation is accomplished
with a round diamond bur, eliminating the entire enamel lesion or defect.
• The completed preparation is made with etched enamel and primed dentin.
A B
C
Small cavitated
class V lesion.
Surrounding enamel
defect is prepared
with round diamond
instrument.
Completed tooth
preparation after
acid etching.
Class V Tooth Preparation for Small lesions not extending into root surface.

18. Class V Tooth Preparation for Large lesions extending onto root surface
A B
C
Class V tooth preparation:
A. Lesion extending onto
root surface.
B. Initial tooth
preparation with 90°
cavosurface margins
and axial wall depth of
0.75 mm.
C. Remaining infected
dentin excavated,
incisal enamel margin
beveled and gingival
retention form
prepared.

19. RESTORATIVE TECHNIQUE
Acid etching and placement of the adhesive.
Insertion and Light – activation of the composite.
Contouring and polishing of the composite.
NOTE: No matrix is needed for class V restorations because
the contour can be controlled as the composite restorative
material is being inserted.

20. REFERENCES
1. Sturdevant’s Art and Science of Operative Dentistry.
2. Clinical Operative Dentistry by Ramya Raghu.

21. THANK YOU!
MADE BY:
AKSHAT SACHDEVA
BDS IIIrd Year