The Finite Analysis Of Mandible Premolar Restored With Post-and-core Crown

Post-and-core restoration is the main method for endodontically treated teeth.Recent technology has produced more materials which can be applied.Dental crown missed and endodontically treated teeth can acquire good and long-term restoration with new materials. Post-and-core crown system includes post,core and crown. They integrated with teeth by the cement, the stress distribution under the force is related with the property of its components.The three dimensional finite element analysis is a method using computer to solve mechanical question about continuous medium. This method is widely used in medical field and regarded as the most useful method in the biomechanics research. In this paper, three-dimensional finite element model of mandible second premolar is reconstructed with thin-layer CT scanning ,Pro / E scientific calculation software. The model was used to analysis stress distribution between different post-and-core materials and dentin, different post-and-core materials and In-Ceram Alumina crown, differentcement and dentin. The results are as following:1.The three-dimensional finite element model of mandible second premolar was reconstructed with thin-layer CT scanning. Pro / E . scientific calculation software. Modularization makes the model more precise,at the same time the software can reconstruct quickly.Oral professionals can engage in the research with this mothed easily and directly.2. When the tooth was restored with post-core, stress distribution of dentin was related to the Yang's modulus of materials. Before restoration,the stress was recorder mainly in the superior third of the root surface.After restorated with high Yang's modulus materials,stress was transferrd to the interface of post and dentin. If polythene fiber reinforced composite and carbon fibre whose Yang's modulus were similar to dentin was used as post material,the stress distribution did not significantly change. Ni-Cr alloy post could decrease stress in the superior thirds of the root surface.But restired with Ni-Cr alloy post, stress in the interface of post and dentin and dentin at post apex increased significantly. Compareed with other materials, Ni-Cr alloy tended to cause root fracture.3.According to nature tooth,tooth preparation should protect live pulp. Endodontical treated teeth should choose proper post-core materials.Different Yang's modulus materials had similar influence on porcelain of In-Ceram Alumina crown. Stress distribution of core was related to Yang's modulus of materials. Compare with other materials, Ni-Cr alloy and zironia could decrease stress of core significantly.4. The post was Ni-Cr alloy, and the thickness of cement was 0.05mm. The materials of cements were zinc phosphate , composite resin , glass ionomer, zinc polycarboxylate respectively. As the Yang's modulus of the cements...