Pedia class II

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Pediatric Dentistry I
Forth Year

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Pedia class II

  1. 1. Modifications  Concave pulpal floor and gingival seat  Rounded internal line angles both decrease stress in the restoration View from distal surface of primary 1st molar B L
  2. 2. Modifications  Relatively wider isthmus width one-third the inter cuspal distance  Conservative proximal extensions light, but cannot pass an explorer tip through
  3. 3. Modifications No proximal grooves No reverse curves
  4. 4. Class II
  5. 5. Class II cavity preparation in Primary molars • Complete class 1 using #330 bur • Extend occlusal outline to marginal ridge • Switch to #245 Bur - 3 mm length • Sweep bur buccolingually in a pendulum motion and in a gingival direction. • Break contacts and check with explorer • Axial wall should follow external contour • Width of isthmus 1/3 of occlusal table • Proximal box widest at gingival margin • Rounded axiopulpal line angle • No bevel at the gingival margins
  6. 6. Class II Cavity Preparation Mandibular
  7. 7. Class II Cavity Preparations No MOD’s on first primary molars !!
  8. 8. Class II Cavity Preparations
  9. 9. Protect adjacent proximal surface
  10. 10. Class II cavity preparation in Primary molars
  11. 11. Cross-sectional View of Class II  Gingival floor position  Box is perpendicular to long axis  Rounded angles
  12. 12. Correct Incorrect Class II cavity preparation in Primary molars
  13. 13. Correct Incorrect Class II cavity preparation in Primary molars
  14. 14. Class II cavity preparation in Primary molars Correct Incorrect Incorrect
  15. 15. Common Errors - Class II’s
  16. 16. Failures of Amalgam Restorations Fracture of the isthmus of a Class II due to insufficient bulk of amalgam Marginal failure in proximal box area due to excessive flare of the cavo-surface margin Recurrent caries failure to extend preparation adequately
  17. 17. w T-band w Tofflemire • does not fit contour of primary tooth well • difficult to fit multiple matrices w Spot welded • allows for multiple matrix placement • requires a spot welder chair side w Auto-matrix • costly Types of Matrices
  18. 18. Spot Welded Matrix  Cut matrix and spot weld ends 3/16 “ wide and thin (..002”) matrix  Form a loop  Hold ends in spot welder  Weld at low setting
  19. 19. Adapting Matrix Band Place band over tooth with welded on buccal Seat band extends 0.5-1 mm gingival to the cavo-surface margin Band extend occlusally .5-1mm beyond the marginal ridge Stabilize band with finger
  20. 20. Adapt Matrix Band to Tooth
  21. 21. Matrix Grasp welded ends with flat-nose, serrated pliers (#110) at center of buccal surface of tooth tightly Spot weld band at crease and trim ends Return to tooth and wedge properly Remove matrix by inserting flat blade instrument between tooth and matrix at crease
  22. 22. Cavity Bases and Liners – Purpose of base prior to condensation is to prevent thermal insulation for the pulp. – Use of calcium hydroxide influences formation of secondary dentin. • Initiates local inflammatory response at site of contact between pulp and calcium hydroxide
  23. 23. Condensation and Carving  “Back to back” condensation of Class II’s  Carving described as “hill and valley”  Polishing procedure
  24. 24. Condensing & Carving of Amalgam • Using an amalgam carrier, add increments & condense using positive finger rest. • Overfill prep, begin to carve and burnish the occlusal portion with a lateral condenser • After initial set, create the marginal ridge using an explorer • Carve restoration & remove excess from margins using a cleoid-discoid or hollenback carver • Carefully remove band and burnish restoration using a ball burnisher. • Apply moist cotton pellet or pumice paste for final smoothening • Remove rubber dam and check occlusion
  25. 25. Finishing of Amalgam Restorations • Reduce tarnish and corrosion • Improve marginal integrity Polishing should be delayed for 24 hours
  26. 26. Interproximal Box • Buccal and lingual walls should go straight out into the interproximal box in Class II cavity preparations • Buccal & lingual walls convergent towards occlusal • Gingival floor just past contact or height of contour, flat & well defined • Axial wall convex to follow the surface anatomy • Axial depth should be 1 mm • Buccal and lingual cusps adjacent to box should have plenty of sound tooth structure left ie. They shouldn't be too thin.
  27. 27. “slot” preparation • Modified class II cavity design for the • placement of RMGIs.
  28. 28. CLASS II PREPARATION COMPARISON • AMALGAM - 0.5 mm into dentin - no cavo-surface bevel - 0.5 mm prox.clearance - isthmus 1.0+ - no gingival bevel - occlusal dovetail • COMPOSITE - 0.5 mm into dentin - cavo-surface bevel - 0.5 mm prox. clearance - isthmus 1.0+ - gingival bevel - no dovetail needed
  29. 29. Lack of buccal clearance / unsupported enamel CLASS II COMPOSITE RESIN RESTORATION
  30. 30. Outline form includes all carious defects
  31. 31. Bevel gingival margin
  32. 32. Gingival bevel
  33. 33. Clearance ( convenience form )
  34. 34. Clearance ( convenience form ) Clearance Place explorer tip on gingival floor and pull through buccal/lingual space
  35. 35. AE – enamel 15 seconds
  36. 36. Rinse thoroughly
  37. 37. Well wedged Tofflemire band
  38. 38. Palodent band - bitine ring
  39. 39. Application of bond resin to moist dentin
  40. 40. Air thin bond resin
  41. 41. Light-cure bond resin 20 seconds
  42. 42. Apply thin layer of flowable C.R.
  43. 43. Apply thin layer of flowable C.R.Light-cure flowable C.R.for 30 seconds
  44. 44. Express a small amount of C.R. before using
  45. 45. Place C.R. with a condenser
  46. 46. 1st. application of C.R.
  47. 47. 1st. application of C.R. Light-cure 1st. layer of C.R. 30 seconds
  48. 48. 2nd. application of C.R.
  49. 49. Use of contact instrument
  50. 50. Light curing 2nd. C.R. application 30 seconds
  51. 51. Hole left after removal of contact instrument
  52. 52. 3rd. application of C.R.
  53. 53. Developing occlusal anatomy before curing
  54. 54. 40 second cure of final increment of C.R.
  55. 55. Use of round bur to develop anatomy
  56. 56. Use an explorer to check for flash/ditching
  57. 57. Use of Soflex disk to shape marginal ridge
  58. 58. Check occlusion / adjust
  59. 59. Finishing diamond Finishing bur White stone Round bur C.R. polishing system
  60. 60. C.R. polishing system
  61. 61. Acid etching prior to placing surface sealant
  62. 62. Application of a surface sealant

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