AZ91D镁合金种植体三维模型骨界面应力有限元分析

目的：利用三维有限元方法分析AZ91D镁合金种植体和钛合金种植体及周围骨界面的应力分布规律。方法：建立下颌第一磨牙区AZ91D镁合金种植体和钛合金种植体三维有限元模型,根据Von Mises标准计算种植体-骨界面应力水平。结果：不同载荷下,AZ91D镁合金种植体和钛合金种植体模型的种植体-骨界面应力分布基本相同：两模型最大应力均位于种植体第一螺纹及颈部皮质骨处;相同载荷下镁合金种植体模型界面应力值稍高于钛合金模型;皮质骨应力分布相似,松质骨区镁合金模型应力分布更均匀;镁合金种植体在水平载荷50N下最大等效应力值是其屈服强度的98.1%。结论：AZ91D镁合金种植体与钛合金有着极为相似的应力分布,镁合金种植体骨界面应力值稍高但垂直载荷下界面应力分布较均匀且更有利于压应力传导。

Three-Dimensional Computerized Stress Analysis of Magnesium Alloy AZ91D in Implant-to-bone Interface

Objective：To analyze stress distribution patterns in implants made of magnesium alloy AZ91Dand Ti6Al-4Vwith three-dimensional finite element analysis（3D-FEA）.Methods：Two three-dimensional finite element analysis models of mandibular first molar with implant were made,surrounded by cortical and cancellous bone.Stress levels were calculated according to the Von-Mises criteria.Results：Magnesium alloy AZ91Dimplants had very similar stress distribution to Ti-6Al-4Vimplants under different implant.The maximum Von-Mises stresses were located in or near the beginning of the fist thread of the implant and the corresponding cortical bone-implant contact region.Higher stresses in magnesium alloy AZ91Dwere observed under the same force.Stress distribution in both of them were similar along the implant-to-spondy interface.Magnesium alloy AZ91Dimplants presented a pattern of better-distributed stress distribution along the implant-to-spondy interface.For the horizontally loading of 50N,the maximum stress values within the implant body were 98.1%of the yield stength.Conclusion：There was little difference in the stress between the two different implants.The stresses in magnesium alloy AZ91Dimplant were higher but a little better distributed along the implant-to-bone interface and in magnesium alloy AZ91Dimplant models the load can be better conducted to bone as interfacial compressive stresses.