All-on-Four和上颌窦提升技术对不同骨质上颌骨应力分布影响的三维有限元分析

3D finite element analysis of the effect of All-on-Four and maxillary sinus floor augmentation in different bone qualities

目的:利用三维有限元分析,比较上颌后牙区骨量不足无牙颌患者在不同骨质条件下,分别采用All-on-Four、上颌窦提升技术时种植体、皮质骨的应力值及钛支架变形量的差异。方法:选取1例牙列缺失上颌骨锥形束CT数据,建立D2、D3、D4三类骨质的实体化模型,在每种骨质下设计两种种植方案,根据有无悬臂于双侧后牙区分别施加200 N垂直载荷,共计12个模型,计算出种植体、皮质骨的von Mises应力值及钛支架的变形量,并进行统计学分析。结果:有悬臂时种植体和皮质骨的von Mises应力值及钛支架变形量显著大于无悬臂时的各项值(P<0.05);上颌窦提升组的种植体、皮质骨von Mises应力值及钛支架变形量均小于All-on-Four组(P<0.05);当骨质类型为D4时,模型中种植体、皮质骨的von Mises应力值及钛支架变形量最大,随着骨质密度的增加,种植体、皮质骨的von Mises应力值及钛支架变形量逐渐减小。结论:上颌窦提升种植设计显示出更优的生物力学行为,适合各类骨质的种植修复。当骨质类型为D2时,可考虑选择All-on-Four技术,应减少或避免悬臂;当骨质类型为D4时,All-on-Four技术应谨慎使用。

Objective:To compare the difference of implant and cortical bone stress value and the deformation value of titanium frame,in the design of All-on-Four and maxillary sinus floor augmentation with varies bone qualities,using finite element analysis in maxillary edentulous with insufficient bone mass in posterior tooth area.Methods:The CBCT data of a maxillary edentulous was selected to establish the solid models of D2,D3 and D4 bone quality.Two implant schemes were designed under each kind of bone quality,and a total of 12 models were applied 200 N vertical load on both posterior teeth with or without cantilever.Then,the von Mises stress values of implants and cortical bones and the deformation of titanium frame were calculated and statistically analyzed.Results:The von Mises stress of implant and cortical bone and the deformation of titanium frame with cantilever were significantly higher than those without cantilever,and the difference was statistically significant(P<0.05).The von Mises stress of implant and cortical bone and the deformation of titanium frame in maxillary sinus floor augmentation group were lower than those in All-on-Four group,and the difference was statistically significant(P<0.05).When the bone type was D4,the von Mises stress value of implant and cortical bone and the deformation of titanium frame were the largest.With the increase of bone quality,the von Mises stress value of implant and cortical bone and the deformation of titanium frame decreased gradually.Conclusions:The maxillary sinus floor augmentation showed more favorable biomechanical behavior than All-on-Four,which was suitable for all kinds of bone qualities.The increase of bone quality was beneficial to the overall stress distribution.When the bone type was D2,we could consider choosing All-on-Four for repair,but the cantilever should be reduced oravoided.When the bone type was D4,the All-on-Four technique should be used cautiously.