Composite class 3 and class 5

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 I ntroduction. Indications for Composite Resin Restorations. Contraindications. Advantages. Disadvantages. 6. Clinical Techniques for Class III Direct C omposite R estorations. 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: Obtaining access to the defect (caries, fracture). Removing faulty structures (caries, defective dentin, defective restoration). 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. T he same bur or diamond is used to enlarge opening for caries removal.

12. Beginning class III tooth preparation(lingual): 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: I ncisogingival section showing axial wall 0.2mm into dentin. B: F aciolingual section showing facial extension and axial wall following the contour of tooth.

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

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: 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 : Lesion extending onto root surface. Initial tooth preparation with 90° cavosurface margins and axial wall depth of 0.75 mm. 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 Sturdevant’s Art and Science of Operative Dentistry . Clinical Operative Dentistry by Ramya Raghu.

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