固定义齿倾斜基牙牙周应力分布的三维有限元研究

Stress distribution in the dental surrounding tissues of the tilted mandibular molar as a fixed bridge abutment: a three-dimensional finite element analysis

目的 :用三维有限元方法对近中倾斜的下颌第二磨牙单独受力及作为固定桥基牙后受力时牙周支持组织中的应力分布进行比较分析。方法 :采用薄层CT扫描技术和Ansys有限元分析软件建立下颌第一磨牙缺失、下颌第二磨牙近中倾斜 3 0°、行双端三单位固定桥修复前后的三维有限元模型 ,施加载荷计算并分析牙周支持组织中的应力分布状况。结果 :修复前 ,第二磨牙近中牙槽嵴顶、根尖处应力值较大 ,修复后 ,第二磨牙根周应力值减小 ,第二前磨牙颈部及根尖应力值增大 ,应力分布得到改善。结论 :在一定的倾斜角度内 ,从生物力学角度来评价固定修复有利于倾斜基牙的牙周健康。

Objective:To compare the stress distribution in the dental surrounding tissues of a tilted mandibular molar before and after the restoration of three-unit fixed partial denture using finite element analysis. Method: One three-dimensional finite element models of 3-unit fixed partial denture in which the second molar were tilted 30 degrees toward the second premolar and its unrestored model were constructed by the combination of the Computed Tomographic (CT) scanning technology and Ansys software.A vertical load of 23kg was applied to the central fossa of the second molar.Compare the stress distribution between two models. Result: The introduction of a fixed partial denture decreased the stress in the bone mesial to the root and adjacent to the apex of the tlted molar and increased the stress surrounding the second premolar. Conclusion: The placement of the fixed partial denture modified the stress distribution around the roots of the tilted molar abutment and favored the tilted molar at the aspect of mechanics.