下颌第一磨牙颊-(牙合)-舌嵌体有限元模型的建立及应力分析

目的观察下颌第一磨牙颊?(牙合)?舌(bucco?occluso?lingual, BOL)嵌体修复后模型内部的应力分布,为BOL嵌体在牙隐裂的临床治疗提供基础依据。方法将Micro?CT扫描技术与Mimics、UG、Ansys、Midas?FEA等软件相结合,建立下颌第一磨牙三维有限元模型,在此基础上形成BOL嵌体修复模型,赋予嵌体IPS e.max CAD材料参数,以完整牙为对照,得到同等载荷条件下的Von?mises应力分布云图,对各模型内部的应力分布结果进行比较。结果完整牙应力在牙冠部主要集中在(牙合)面的中央裂沟,BOL嵌体修复后牙体洞型的应力主要集中在窝洞的近远中洞壁、轴髓线角和龈壁,嵌体的应力主要分布在嵌体底部、轴壁和龈壁。结论 BOL嵌体修复改变了完整牙体模型内部的应力分布状况,从而改善了(牙合)面窝沟处的应力集中现象,对于牙隐裂的治疗起到积极的作用。

Establishment and stress analysis of buccal-occlusal-lingual inlay finite element model of mandibular first molar

Objective To observe the stress distribution according to a model of the bucco-occluso-lingual(BOL)inlay of mandibular first molar after restoration to provide a basis for the clinical treatment of cracked tooth with BOL in-lay.Methods A three-dimensional finite element model of mandibular first molar was established by combining micro-CT scanning technology with Mimics,UG,Ansys and Midas-FEA software.Based on this model,a BOL inlay restoration model was established.The material parameter of inlay IPS e.max CAD was given,and a Von-mises stress distribution nephogram under the same loading condition was obtained.The results of the stress distribution in each model were compared.Results The stress of intact teeth is mainly concentrated in the central fissure of the occlusal surface at the crown.The stress of the cavity after BOL inlay restoration is mainly concentrated in the mesial and distal walls of the cavity,the axial-pulpal line angle and the gingival wall.The stress of the inlay is mainly distributed at the bottom of the inlay,axial wall and the gingival wall.Conclusion BOL inlay restoration change the stress distribution in the com-plete dental model,which relieves the stress concentration in the fossa and groove of the occlusal surface and can play an active role in the treatment of cracked tooth.