【摘要】 目的 应用有限元方法观察不同牙槽骨高度下桩核修复后牙本质内的应力分布情况。方法 建立上颌中切牙桩核修复的三维有限元模型,并按照牙槽骨高度降低1/4、1/3和1/2建立修改模型,对模型斜向加载,计算牙体各部位最大应力。结果 随着牙槽骨高度的降低,牙本质内部最大应力明显增高,牙体与桩交界部位的最大应力变化呈相同趋势,且愈靠近牙根表面应力值愈高,在4个模型中最大应力都位于牙根上1/3,在牙齿唇侧颈部有明显的应力集中。结论 牙槽骨高度的变化显著影响桩核修复后牙齿内的应力变化,两者间呈反比例关系。更多还原

【Abstract】 Objective To investigate the stress distribution in various heights of alveolar bone in post crown, and evaluate the hiomeehanism in post crown. Methods By CT scanning, graph digitizing and auto cad software, the three-dimensional finite element entity grid model was built, which was a maxillary central incisor restored with post crown. By simulating the height of alveolar ridge and reducing 1/4 ,1/3 ,1/2 of the height to set up modified model under static loading,the dentin stress was analyzed. Results The stress changes of each part of the interface of teeth and post were similar to those of each part of the teeth,and the value of the stress was larger and closer to the root surface.The stress distribution had an increasing tendency when the height of alveolar decreased and the maximum stress was recorded in the superior one third of the root.The significant concentration of stress occurred in the cervical of the facial. Conclusion The change of alveolar ridge’ s height affected the stress change of teeth restored with post crown, and an inverse proportion existed.更多还原