Class 1 and 2 direct composite and tooth colored material restoration_103112.pptx

Class I and II direct composite restoration

1. Class I,II & III direct composite and tooth- colored restoration

2. Insertion and light activation of composite Bilayered (sandwich) Technique; The use of an RMGI liner or flowable composite liner may reduce the effects of polymerization shrinkage stress because of their favorable elastic modulus. This technique is often referred to as bilayered or sandwich technique.

3. RMGI; The advantages of using RGMI is following. A. The RMGI material bonds to the dentin without opening the dentinal tubules ,thus reducing the postoperative sensitivity. B. The RMGI having the property of releasing fluoride provide a better seal and having anticariogenic property.

4. C. The favorable elastic of modulus of the RMGI reduces the effects of polymerization shrinkage stress. Flowable composite Liner; Flowable composite are also used as liners under the posterior composite restoration. They can reduce the negative effects of polymerization.

5. Composite placement technique Incremental technique; It is important to place the composite incrementally to maximize the polymerization depth of cure and reduce the negative effects of polymerization shrinkage. The deep portions of the tooth preparation are restored first, with increments of no more than 2 mm in thickness.

6. The operator should used the unprepared tooth as reference for prepared the enamel surface of the restoration. The operator places and light activates one increments per cusp at a time and continuous to until the restoration is done.

7. Configuration factor The term of configuration factor or c-factor has been used to describe the ratio of bonded to un bonded surfaces in a tooth preparation and restoration. A typical class I tooth preparation will have a high c-factor of five surfaces( Mesial,distal,lingual,facial,pulpal ) and one bonded surface (occlusal).

8. The higher the C-factor the higher will be rate of polymerization shrinkage.

9. Contouring and polishing the composite The occlusal surface is shaped with a round burs or oval carbide/diamond finishing bur.

10. Clinical technique for class II direct composite restoration There are 3 basic steps involved in the class II cavity design for direct composite restoration. 1. Initial clinical procedure 2.Tooth preparation 3.Clinical technique for class II direct composite restorations The initial clinical procedure and tooth preparation are same described in class I cavity design.

11. There are two types of lesion can occur in class II cavity design like small lesion or small class II cavity and large class II cavity lesion. Small Class II direct composite restoration; There are 3 basic design used for small class II lesion. Conservative design Box- only design Slot design

12. Conservative design The preparation are less specific in form having a scooped out appearance without uniform or flat pulpal or axial walls. Clinical technique; A small round bur or elongated pear diamond or bur with round features can be used for this preparation to scoop out the caries or faulty material from the occlusal and proximal surface.

13. The pulpal and axial depths are dictated only by the depth of the lesion and are not made uniformly. The proximal wall can be made with the straight sides instrument.

14. Box –only design This design is indicated when only the proximal surface is defective, with no lesions on the occlusal surface. Clinical technique; A proximal box is prepared with a small elongated pear or round instrument ,held parallel to long axis of the tooth crown. The instrument is extended through marginal ridge in a marginal direction.

15. The axial depth is dictated by the caries extent lesion or fault. The more box like with the elongated pear and the more scooped with the round. No beveling or secondary retention is indicated.

16. Moderate to large class II Direct composite restorations This cavity is prepared on the occlusal and proximal surface of the teeth. This cavity resembles the amalgam tooth preparation which include an occlusal step and proximal step. Occulusal steps; A No 330 or No 245 shaped diamond bur is used to enter the pit near to proximal caries lesion. The instrument should be held parallel to long axis of the crown.

17. STEP 2; If the opposite proximal surface are not involved then opposite marginal ridge should be maintained intact. The depth of pulp should be approximately 0.2mm inside the DEJ.The pulpal floor are relatively flat in faciolingual plane but may rise and fall slightly in mesiodistal plane. STEP 3; The occlusal extension toward the proximal surface is prepared as conservatively as possible. The instrument should be extend 0.5 mm toward proximal surface through the marginal ridge.

18. Proximal box The facial, lingual and gingival extension of proximal box is determined by the following. 1.The extent of caries lesion 2.Amount of old restorative material The two clinical possibilities are followings, PROXIMAL BOX WITHIN THE CONTACT; If all of the defect can be removed without extending the proximal preparation beyond the contact, the restoration of the proximal contact with the composite is simplified.

19. Proximal box beyond the contact It is required to extend the proximal box beyond contact with the adjacent tooth(Provide the clearance with the adjacent tooth),it may simplify the preparation ,matrix placement and contouring procedure.

20. Clinical technique Step 1; The 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. Step 2; The faciolingual cutting motion follows the DEJ and is usually in slightly convex arc outward. During the entire cutting ,instrument should be held parallel to the long axis of the tooth crown. Step3;The gingival margins should be prepared flat with approx 90 degree cavosurface margin.

21. Extensive class ii direct composite restoration Indication; Due to economic factors that prevent patient from selecting a more expensive indirect restoration. As a foundation restoration for indirect restoration (Crown and inlays) when the operator determines that insufficient natural tooth structure remains to provide adequate retention and resistance form for the crown. As an interim restoration while waiting to determine the pulpal response or whether or not restoration will function perfectly.

22. Clinical consideration The primary difference of these very large preparation include the following; Some or all of the cusps may be capped. Extensions in most directions are greater. Secondary retention feature are used. More resistance form feature are used. Retention form for foundation must be placed far enough inside the DEJ(at least 1mm) to remain after the crown preparation is done subsequently.