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目的探讨不同桩核材料对牙本质应力分布规律的影响，为临床桩核材料的选择提供依据。方法本研究于2012年3—7月在清华大学计算机教研室进行。利用螺旋CT断层图像，构建上颌第一磨牙舌侧1／2缺损桩核及全瓷冠修复的三维有限元分析模型，设计垂直集中栽荷600N的加栽方式，分析5种不同材料（普通复合树脂、石英纤维、铸瓷、金合金和镍铬合金）桩核冠修复后的牙本质应力大小及分布状况。结果牙本质的Vonmises应力集中于预备后基牙的袷方与全瓷冠修复体的接触部分；最大张应力集中于预备后基牙的颊侧牙颈部。牙本质的应力值均随着5种桩核材料弹性模量的减小而增大。结论桩核材料弹性模量不同对牙本质的应力分布影响较大，临床上的残根残冠进行桩核冠修复时，应尽量选用弹性模量较高的桩核材料，这样有利于保护残余的牙体组织。

Three-dimension finite element analysis of stress of residual dentin of various post-and-core applications.

Objective To investigate the relationship between the different teeth post and core materials and stress dis- tribution of residual dentin and provide the basis for the design of clinical repair. Methods The fault images of spiral CT were used to construct the finite element analysis model of 1/2 defect in lingual side of maxillary first molar and all-ceramic crown, and load way was designed： 600 N load was vertically concentrated, and ANSYS software was used to analyze the stress values of of residual dentin on five different teeth post and core materials. Results The Von mises stress of dentin was concentrated on the contact part of the gnathie side of prepared body of abutment in buccal side, the maximum tensile stress was concentrated on tooth neck in buccal side of the prepared body of abutment in buccal side. The stresses of dentin increased when the elastic modulus of the post core materials decreased. Conclusion Different elastic modulus of the post-core materials have a great impact on the stress distribution of dentin. For the clinical residu- al root on the restoration, we should use post-core with high elastic modules in order to protect the residual teeth.