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CHEN Zhi Wuhan University School of Stomatology Operative Dentistry 2.

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Presentation on theme: "CHEN Zhi Wuhan University School of Stomatology Operative Dentistry 2."— Presentation transcript:

1 CHEN Zhi Wuhan University School of Stomatology Operative Dentistry 2

2 Definition of Operative Dentistry Operative dentistry is the ART and SCIENCE of the diagnosis, treatment, prognosis of defects of teeth which do not require full coverage restorations for correction.

3 Indication of Operative Dentistry  Caries;Caries  Malformed, discolored,Malformed, discolored, or fractured teeth;fractured teeth;  Restoration replacement.Restoration replacement.

4 Program of Operative Treatment  Patient assessment  Examination and diagnosis  Treatment planning  Pain control: local anesthetic  Isolation of the operating field

5  Cavity preparationCavity preparation  Matrix application  Preparation of materials  Insertion and carving of materials  Finishing and Polishing Program of Operative Treatment

6 Cavity Preparation The mechanical alteration of a defective, injured, or diseased tooth in order to best receive a restorative material which will re-establish a healthy state for the tooth including esthetic corrections where indicated, along with normal form and function.

7 Cavity Structure  walls  angles  cavity

8 Classification of cavity  Class I  Class II  Class III  Class IV  Class V  Class VI —G.V.Black in 1908

9 Cavity  Simple cavity: only one tooth surface is involved.  Compound cavity: two surfaces are involved.  Complex cavity: three or more surfaces are involved.

10 QUIZ TIME

11 Class 1 Class 2 Class 1 Class 2 Class 3 Class 4 Class 5 Class 6

12 Stages and Steps in Cavity Preparation Initial cavity preparation stage Final cavity preparation stage

13 Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

14 Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

15 Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

16 Outline Form and Initial Depth Ⅰ Definition: placing the cavity margins in the positions they will occupy in the final preparation; preparing an initial depth of 0.2~0.8 mm pulpally of the dentinoenamel junction position or normal root surface position.

17 Maxillary Class Ⅰ outline form

18 Mandibular Class Ⅰ outline form

19 Maxillary Class Ⅱ outline form

20 Mandibular Class Ⅱ outline form

21 Common Error

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23 Outline Form and Initial Depth Ⅱ Principles: without any exception all friable and/or weakened enamel should be removed all faults should be included all margins should be placed in a position to afford good finishing of the margins of the restoration.

24 Outline Form and Initial Depth Ⅲ Features: preserving cuspal strength preserving marginal ridge strength minimizing facio-lingual extension using enameloplasty connecting two close faults or cavities restricting the depth of the preparation into dentin.

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28 Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

29 Primary Resistance Form Ⅰ Definition: The shape and placement of the cavity walls that best enable both the restoration and the tooth to withstand, without fracture, masticatory forces delivered principally in the long axis of the the tooth.

30 Primary Resistance Form Ⅱ Principles: To utilize the box shape with a relatively flat floor to resist occlusal loading by virtue of being at right angles to mastication force; To restrict the extension of the external walls (keep as small as possible) to allow strong cusp and ridge areas to remain with sufficient dentin support;

31 Primary Resistance Form Ⅲ Principles: To have a slight rounding of internal line angles to reduce stress concentration in tooth structure; To provide enough thickness of restorative material to prevent its fracture under load.

32 Primary Resistance Form Ⅳ Feature: Box shape Relatively flat floors Inclusion of weakened tooth structure Preservation of cusps and marginal ridges Rounded internal line angles Adequate thickness of restorative materials Reduction of cusps for capping if indicated

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34 Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

35 Primary Retention Form Ⅰ Definition: The shape or form of the prepared cavity that resists displacement or removal of the restoration from tipping or lifting forces. In many respects retention and resistance form are accomplished in the same cutting procedure.

36 Primary Retention Form Ⅱ Principles: depending on the materials Amalgam restoration: developing external cavity walls that converge occlusally and dovetail design

37 The devotail design provide retention form to the occlusal portion of the cavity. The occlusal convergence of the walls offers retention in the proximal portion of the cavity against displacement occlusally.

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39 Primary Retention Form Ⅲ Principles: depending on the materials Composite restoration: a mechanical bond between the material and conditioned, prepared tooth structure.

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41 Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

42 Convenience Form Ⅰ Conception: The shape or form of the cavity that provides for adequate observation, accessibility, and ease of operation in preparing and restoring the cavity.

43 Convenience Form Ⅱ Principles:  Allow access for caries removal  Allow access for restoration placement  Allow access to margins for finishing, evaluation and cleaning

44 Convenience Form

45 Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

46 Removal of any remaining infected dentin if indicated Definition: The elimination of any infected carious tooth structure or faulty restorative material left in the tooth after initial cavity preparation.

47 Removal of dentinal caries using round burs and spoon excavators

48 Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

49 Pulp protection Using liners or bases to protect the pulp or to aid pulpal recovery or both.

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54 Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

55 Secondary resistance and retention forms Ⅰ Most compound and complex cavity preparations require additional resistance and retention form. The exception being those preparations that are very conservative.

56 Secondary resistance and retention forms Ⅱ Mechanical forms Cavity wall conditioning form

57 Mechnical form:  Proximal locks  Proximal slots

58 Proximal locks

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61 Slot on gingival wall

62 Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Finishing external walls Step 9 Final procedures

63 Finishing the external walls Ⅰ Definition: is the further development of a specific cavosurface design and degree of smoothness that produces the maximum effectiveness of the restorative material being used.

64 Finishing the external walls Ⅱ Objectives: To create the best marginal seal possible between the restorative material and tooth structure; To afford a smooth marginal junction; To provide maximum strength of both the tooth and the restorative material at and near the margin.

65 The strongest enamel margin is that margin which is composed of full-length enamel rods that are supported on the cavity side by shorter enamel rods, all of which extend to sound dentin.

66 Finishing the external walls Ⅲ The design of the cavosurface angle The degree of smoothness of the wall

67 The design of the cavosurface angle: depending on the material  amalgam: 90°  composite: beveling 30°~ 40°

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71 Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

72 Final procedures  cleaning  inspecting  varnishing  conditioning

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75  Cavity preparation  Matrix application  Preparation of materials  Insertion and carving of materials  Finishing and Polishing Program of Operative Treatment

76 Matrix Application Tofflemire Matrix System Ivory Matrix System

77 Matrix retainer, Band & Wedge

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79 Matrix in Retainer

80 Contour Matrix Rounded instrument such as a spoon excavator

81 Matrix on Tooth

82 Occlusal View

83 Wedge place

84 Contour Band

85 Ready for restoration

86  Cavity preparation  Matrix application  Preparation of materials  Insertion and carving of materials  Finishing and Polishing Program of Operative Treatment

87 Armamentarium  Amalgam Capsule  Amalgamator  Squeeze Cloth  Amalgam carrier

88 Activate Mercury

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91  Cavity preparation  Matrix application  Preparation of materials  Insertion and carving of materials  Finishing and Polishing Program of Operative Treatment

92 Insertion and carving Class Ⅰ Class Ⅱ

93 Armamentarium  Amalgam Condensers  Anatomic Burnishers  Carves — Cleoid or Discoid

94 Check condenser fit

95 First increment

96 Start with the smallest condenser

97 Step condenser over mass

98 Continue adding increment

99 Condense toward walls

100 Use alternative instruments

101 Overpacked

102 Create initial grooves

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104 Carve to margin

105 Enhance grooves

106 Remove flash

107 Final shape and burnishing

108 Completed restoration

109 Initial Increment

110 Initial Condensation

111 Lateral Condensation

112 Overpacking

113 Marginal Ridge Condensation

114 Condense to Margins

115 Create Occlusal Embrasure

116 Occlusal Embrasure

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119 Removing Ridge

120 Removing Band

121 Flash & Excess

122 Moving Excess

123 Check with interproximal carve

124 Instrument on Tooth Structure

125 Completed Restoration

126 Rubber dam removal

127  Cavity preparation  Matrix application  Preparation of materials  Insertion and carving of materials  Finishing and Polishing Program of Operative Treatment

128 Polishing

129 Evaluate the restoration Class I Verify that cavosurface margin can be seen — Flash — Underfilled — Voids Check the overall shape of the anatomy — Look for bulky ridges that might be high in occlusion

130 Evaluate the restoration Class II Check proximal contact Check flash and overhangs proximally Check underfill proximally Check outline form

131 Check Occlusion Evaluate carefully with marking paper or ribbon in Miller forceps Check gently in centric occlusion Check all excursive movement

132 Strasbourg

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