full metal.pptx

presentation

1. بسم الله الرحمن الرحيم

2. The Complete metal cast crown Full metal crown

3. Definition : It is a metallic artificial restoration that restores the coronal portion of the tooth in function, contour and anatomy

4. Advantages Has great retention than partial coverage. Has great resistance form. Has great strength. The complete cast crown allows the dentist to modify axial tooth contour. Easy modification of oclussion.

5. Disadvantages Less conservative than partial coverage. Bad esthetic. Doesn’t allow electric pulp vitality test.

6. Indications

7. As a bridge retainer. As a single crown restoration.

8. In endodontically treated teeth. Excessive destruction by caries or truma

9. When maximum retention and resistance are needed. Short clinical crown Long span bridge

10. Correction of axial contour . Buccaly inclined tooth Over erupted tooth

11. Indications As a single crown restoration. As a bridge retainer. In posterior teeth. Teeth excessively destroyed by caries or trauma. In endodontically treated teeth. When maximum retention and resistance are needed. Correction of axial contour of malaligned teeth. Patients with high caries index and bad oral hygiene.

12. Contraindications

13. In anterior teeth.

14. Buccal wall is intact.

15. If less than maximum retention and resistance are needed. Long clinical crown short span bridge

16. contraindications -In anterior teeth. -When buccal wall or lingual wall is intact. -If less than maximum retention and resistance are needed. -When more conservative restoration is indicated.

17. Alloys used in construction

18. 1) High noble Metal alloys ; contains 60% noble metal , 40% gold: Au-PL-Pd , Au-Pd, AU-Ag-Pd 2) Noble Metal alloys; contains 25% noble metal with no requirement of gold: Ag-Pd 3) Base Metal alloys ; contains less than 25% noble metal; Ni-Cr, Co-Cr, Ti

19. Armamentarium

20. Steps of Preparation

21. 1) Occlusal Reduction

22. To create a uniform space between the occlusal surface of reduced tooth and the opposing teeth.

23. Depth orientation grooves

24. Using fissure bur or rounded end tapered diamond

25. In buccal and lingual developmental grooves and marginal ridges

26. Tooth structure between the grooves is removed preserving the occlusal configuration

27. Amount of reduction should be uniform to allow adequate thickness of metal

28. To check the occlusal clearance Utility wax Reduction gauge Registration material

29. To obtain an ideal axial preparation every two opposing walls should be parallel to each other with an occlusal convergancey 2-6 degrees

30. Undercut!! Over-convergence!!

31. 2) Axial Reduction

32. Finishing line should be a replica of half of the tip of round ended of tapered diamond stone used.

33. Chamfer should never be wider than half of the tip of stone used. Otherwise a lip of unsupported enamel will be left! (Gutter finishing line)

34. Finishing line 1) Type; Chamfer finishing line. 2) Thickness ; 0.3 mm in case of base metal alloy. 0.5 mm in case of noble metal alloy. 3) Location ; Supragingival . Subgingival .

35. It is located Supragingival in all cases except ; Deep caries or erosion. Restoration ( finishing line should never be places on a restoration). Short crown. Proximal contact area extend to gingival crest. Root sensitivity.

36. Rounding of all line angles Continuity of finishing line (using end-cutting bur )

37. FINISHED PREPARATION

38. FINISHED RESTORATION

39. Over tapering of opposing axial walls result in reduced retention . -To overcome this error, we either; -Improve retention by adding grooves -Prepare a band of few mms of tooth structure with restricted 6 degree taper.