3G.V. Black’s Approach to Cavity Preparation 1. Outline formBased primarily on the location and extent of the caries.Final outline form is not established until the carious dentin and, usually, its overlying enamel has been removed
4G.V. Black’s Approach to Cavity Preparation 2. Resistance formResistance to both fracture of the tooth and filling material must be built in so both will be resistant to fracture during function
5G.V. Black’s Approach to Cavity Preparation 3. Retention formThe tooth preparation must be shaped in such away to retain the filling material, withoutweakening the remaining tooth structure
6G.V. Black’s Approach to Cavity Preparation 4. Convenience formAllows adequate observation, accessibility, and ease of operation during the preparation and restoration of the tooth.Only the minimal amount of reduction that will provide the necessary convenience should be done
7G.V. Black’s Approach to Cavity Preparation 5. Removal of the remaining cariesDeeper caries not removed by the initial cavitypreparation is now removed. Care must beexercised as the pulp may be in close proximity.
8G.V. Black’s Approach to Cavity Preparation 6. Finish of enamel walls and marginsRemove unsupported enamel, make the marginssmooth and continuous to facilitate finishing ofthe restoration.
9G.V. Black’s Approach to Cavity Preparation 7. Clean the cavity preparationRinse away all debris and dry the cavitypreparation.
22Matrix systemA matrix system provides and takes the place of the proximal tooth surface that was removed to restore the proximal contours and contact to their normal shape and function.
23Posterior Matrix System Universal retainerAlso referred to as the Tofflemire retainer. This device holds the matrix band in position. The retainer is positioned most commonly from the buccal surface of the tooth being restored.
25Posterior Matrix System Matrix bandsMatrix bands are made of flexible stainless steel and are available in premolar, molar, and universal sizes and thicknesses.The larger circumference of the band is the occlusal edge and is always placed toward the occlusal surface.The smaller circumference of the band is the gingival edge and it is always placed toward the gingiva.
26WedgesA wedge is either triangular or round and made of wood or plastic.The wedge is inserted into the lingual embrasure to position the matrix band firmly against the gingival margin of the preparation.