| Summary: | 碩士 === 國立成功大學 === 醫學工程研究所碩博士班 === 94 === Endodontically treated teeth are prone to fracture, but investigations about restorative variables related to fracture are often inconclusive and contradictory. The effect of different anatomic shapes and materials of posts on the stress distribution in an endodontically treated incisor was evaluated in this work. The purpose of this study was to analyze the stresses in post-restored teeth by using finite element method, and the variables evaluated were loading modes, shapes, diameters, and materials of the posts. The model of the restored tooth consisted of post-and-core, a crown, dentin, periodontal ligament, cortical and cancellous bone, and gingiva. Either of the models combining three post shapes (cylindrical, tapered and two-stage cylindrical) and five different materials (gold alloy, stainless steel, titanium, carbon fibre and glass fiber) was analyzed its contribution in the stress pattern in the post-restored tooth. Three-dimensional stress analysis was performed using the Finite Element Method. Three static loads of 100N was applied at vertical, horizontal and oblique directions on the incisal edge, the generated von Mises stress and deformation were calculated. Results showed that the increase of post diameter and elastic modulus would stiffer the post thus increasing the post stress. On the other hand, the dentin stress would reduced with the increasing of post stress. The loading mode is a vital factor to affect the peak dentin stress magnitude and location. Horizontal force would induce a harmful bending effect on the tooth structure, therefore, the restoration of the devitalized teeth should be cautious to prevent or reduce the bending effect.
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