下颌第一磨牙静力与冲击下的三维有限元力学分析

目的：研究人体下颌第一磨牙在分别承受静载和冲击载荷下的力学响应.方法：结合三维激光扫描、逆向工程、三维有限元分析等技术,建立了人体下颌第一磨牙的三维有限元模型.研究其在不同加载方案下的全场应力分析,并通过Mohr强度理论对牙体进行了校核.结果：下颌第一磨牙在两种不同载荷下的应力分布基本相同.最大静载荷下牙体硬组织的最大Mohr应力值小于拉伸极限强度.冲击载荷下的牙体硬组织的最大Mohr应力值相当于静载荷下的应力值乘以大于1的冲击系数.结论：对于牙体,冲击载荷下的力学响应比静载荷下的更显著,但牙周膜可以起到缓冲冲击载荷的作用.

The three-dimensional finite element analysis on the mandibular first molar under static and impact loads

Objective:To analyse the mechanical response of the human mandibular first molar under static load and impact load,respectively.Methods:The 3-dimensional Laser scanning,reverse engineering,and 3-dimensional finite element analysis were utilized to build a 3-D finite element model of mandibular first molar.The models' whole-field stresses under different loads were also analyzed,and Mohr Strength Theory was chosen to check the tooth models.Results:The stress distributions in the mandibular first molar were basically identical under both loads.The maximum Mohr stress value in the tooth tissues under static load was smaller than the stretch limit strength of dentin.The maximum Mohr stress value in the tooth tissues under impact load was equivalent to that under static load be multiplied by a impact factor(which is always larger than 1).Conclusion:The impact response of the mandibular first molar is greater than the static response.However,the periodontal tissues are capable of easing the response under impact load.