牙体解剖学精品课件（中山大学）5.银贡充填.docVIP

Dental caries restoration Principal of dental restoration Remove the decayed tissue Keep the healthy tissue, prevent pulp vitality Design and preparation of resistance form and retention form Basic concept One Abbreviations for simple, compound, and complex cavities MOD: :Mesio-occlusal-distal DO: :Disto-occlsal MO: :Mesio-occlusal MI: :Mesio-incisal DI: :Disto-incisal LI: :Linguo-incisal DL: :Disto-lingual MODBL: :Mesio-occluso-disto-bucco-lingual I=incisal, M=Mesial, D=Distal, B=Baccal, O=Occlusal, L=lingual Cavity classification G.V. Black developed five standard cavity classifications Cavity classification by G.V. Black (simplified) Class I. Caries affecting pit and fissures. Class II. Caries affecting the approximal surfaces of posterior teeth. Class III. Caries affecting the approximal surfaces of anterior teeth Class IV. Caries affecting the approximal surfaces of anterior teeth and involving the incisal angle. Class V. Caries affecting the cervical surfaces Basic concept Two Basic concept Three Resistance form The shape given to a prepared cavity to enable the restoration and remaining tooth structure to withstand masticatory stress (咀嚼压力) without fracture. Main resistance forms: 1. Cavity depth Provide enough space for thickness of restorative material to prevent its fracture. Restoration supported by sound dentine. Main resistance forms 2. Box shape with relatively flat floor. Masticatory forces are directed along the long access of the tooth Main resistance forms 3. Step-Structure Main resistance forms 4. Cavo-surface lines are smoothly rounded curves, and are kept away from areas of stress such as inclination and tips of cusps. Main resistance forms 5. Remove any unsupported enamel. 6. All weakened enamel walls and cusps should be removed. Retention Form Definition The shape or form of the conventional preparation that resist displacement or removal of the restoration from later