两种双根管桩核冠的有限元分析

Stress analysis of two twin-dowel designs using ANSYS finite element method

目的:本文采用有限元法分析3种材质的桩制作的锥形、柱形双桩核冠修复体,在力作用下的应力分布情况。方法:通过上颌第一前磨牙的颊舌截面建立锥形、柱形双桩设计的有限元模型。100N的力分别以如下方向施加:(1)水平向施加于牙面;(2)垂直向;(3)45°角。通过ANSYS 5.7程序得到关于锥形、柱形双桩核冠修复体的应力云图,投影到桩表面及牙根表面的综合应力峰值。结果:锥形桩尖端的应力峰值大于柱形桩,在一部分柱形桩核冠修复体的根尖区,出现应力放大的情况。结论:为了防止桩折,根管桩的形态选择比材料更重要。柱形桩吸收能量的能力,低于锥形桩。柱形金合金双桩核冠修复体,是最佳的设计。

Objective: This study investigated the influence of occlusal stresses on twin-cylindric dowels and twin-tapered dowels made of three different materials by using 2-dimensional finite element analysis models. Methods: A 2-dimensional finite model was constructed in a bucallingual cross-sectional view of a maxillary first premolar. A 100Newton force ,simulating masticatory force, was applied from three directions: (1) at a horizontal load on the occulsionsurface, (2) at a vertical load, (3) at a 45-degree diagonal load. The contour plot results of twin-tapered and twin-cylindricposts models owing to stress changes were got by ANSYS 5.7 program, as well as the von mises stress results which wereprojected on the section of the twin-post and the root. Results: The stress that was produced by twin-cylindric posts withmaterial of gold alloy was the least, the stress that was produced by the twin-tapered posts with material of stainless steelwas the biggest. At the tooth apical area, the stress peak of the twin-cylindric post-core system became larger than thetwin-tapered post-core system. Conclusion: In order to prevent the post fracture, the choice of the shape of the post ismore important than the material. The ability of the energy absorption for the twin-cylindric posts is less than that for thetwin-tapered posts.