下颌前磨牙不同角度桩核冠的三维有限元应力分析

目的分析不同角度的下颌第二前磨牙桩核冠修复时牙本质的应力分布情况。方法在AnsysWorkbench软件中对下颌第二前磨牙在正常角度及颊向、舌向分别倾斜10°、20°、30°的桩核冠模型进行牙本质应力分析。结果各组都在颊舌侧牙颈部出现高应力区,牙本质应力与倾斜角度的大小成正相关关系,载荷相同时,牙根舌向倾斜组的应力大于颊向倾斜组。结论临床上采用铸造镍铬合金桩核矫正颊、舌向倾斜的下颌第二前磨牙时,根管预备过程要注意保证唇舌侧根管壁厚度,并应避免牙根过度倾斜,尤其要避免过度舌侧倾斜,防止根折。

Three-dimensional finite element analysis of models of mandibular premolar restored with post crown at various angles

Objective To investigate stress distribution in models of mandibular second premolar restored with post crown at various angles.Methods The software Ansys Workbench was adopted to analyze stress distribution in models of mandibular second premolar restored with post-core at various angles.Results The stress concentration of each model was observed at buccolingual cervical regions.The stresses in roots were positively related to the tilted angles.However,the stresses were higher in the roots declined lingually than in that declined buccal of the same load.Conclusion The results suggest that when the mandible second premolar declined buccal or lingually was rectified with cast Ni-Cr alloy post and PFM crown,it is important to assure the thickness of the buccolingual canal wall during tooth preparing,and the root should not be tilted excessively, especially not be tilted lingually excessively.