不同形态种植体在两种骨质内以不同角度植入的应力分析

Stress Analysis of Different Types of Implants Implanted in Two Types of Bone at Different Angles

目的:运用三维有限元分析法对比研究不同骨质条件下种植体的形态和植入角度对种植义齿各个部件及周围骨质应力的影响。方法:本实验利用相关软件建立柱形和锥形种植体几何模型,分别以0°、10°、20°、30°角植入到Ⅱ类和Ⅲ类颌骨模型,并以对应角度的两段式个性化基台修复,通过模拟前牙的3种受力状态对模型进行加载,观察各组模型的应力峰值以及应力分布情况。结果:种植义齿各部件及周围骨质的应力随种植体植入角度的增加而增大;相同载荷条件下种植体周围骨质应力峰值为Ⅱ类骨明显小于Ⅲ类骨;柱状种植体组种植体自身的应力峰值小于锥柱状种植体组,而其周围骨质以及上部的Ti-base的应力峰值则相对较大。结论:行种植手术时应尽量使种植体方向与天然牙轴向一致以降低侧向力的不良影响;Ⅱ类骨相较Ⅲ类骨更有利于种植义齿应力的分散;锥形种植体有利于应力的分散,但其本身较柱形种植体更易发生机械并发症。

Objective:To compare the effects of implant shape and implant angle on the stress of implant components and surrounding bone under different bone conditions by three-dimensional finite element analysis(FEA).Methods:The geometric models of cylindrical and tapered implants were established by using relevant software.The implants were implanted into classⅡand classⅢjaw models at the angles of 0°,10°,20°,and 30°respectively,and the two-stage individualized abutment with corresponding angles was used for restoration.The models were loaded by simulating three stress states.The peak stress and stress distribution were observed.Results:The stress of each component of the denture and the surrounding bone increased with the increasing of implant angle.Under the same load condition,the peak stress around the implant in classⅡbone was significantly smaller than that in classⅢbone.The peak stress in the columnar implant group was smaller than that in the tapered implant group,while that in the surrounding bone and the upper Ti-base stress was relatively larger.Conclusion:The direction of the implant had better be aligned with the axis of natural tooth to reduce the adverse effects of lateral force.ClassⅡbone was more conducive to disperse the stress than classⅢbone.The tapered implant was beneficial to disperse the stress and help to protect the surrounding bone tissue,however,it was more prone to mechanical complications than the cylindrical implant.