下颌第一磨牙三维有限元模型的建立

Establishment of three-dimensional finite element model of first permanent mandibular molar

目的应用有限元法建立下颌第一磨牙模型,为其相关的生物力学分析奠定基础。方法通过CBCT扫描获取实验图像,Mimics软件读取图像并进行初步处理,Geomagic软件精修,造型软件Solidworks装配各模块和有限元软件Ansys Workbench划分网格,并分析垂直和斜向载荷下牙体硬组织的受力情况。结果快速准确的建立了具有牙釉质、牙本质、牙髓、牙骨质结构的下颌第一磨牙三维有限元模型。牙体硬组织的应力主要集中在咬合力的加载区、牙颈部和根尖区。垂直向载荷下,牙釉质等效应力(106.24 MPa)>牙本质等效应力(49.92 MPa);斜向载荷下:牙釉质等效应力(109.36 MPa)>牙本质等效应力(78.55 MPa);斜向载荷时,牙釉质和牙本质的等效应力大于垂直向载荷的应力值。结论通过CBCT扫描结合Mimics、Geomagic、Solidworks和Ansys Workbench软件的建模方法快捷有效,且建立的模型具有良好的几何和生物力学相似性。

Objective To establish three-dimensional finite element model of the mandibular first molar.Methods The tomography date of the mandibular first molar and their supporting tissues were obtained by CBCT scanner.Mimics software was used to read and deal with tomography data, Geomagic software to modify precisely,Solidworks software to assemble all of the modules and Ansys Workbench software to divide gridding.And to analyze the stress distributions under various loading conditions.Results A three-dimensional finite element model of the mandibular first molar included enamel, dentinum, dental cavity was accurately established.Under vertical and oblique load,the stress of enamel and dental mainly concentrated on the area loading bite force and the cervix and root apical region.Under vertical load,the effect force of enamel(106.24 MPa) was greater than that of dental(49.92 MPa).Under oblique load, the effect force of enamel(109.36 MPa) was greater than that of dental(78.55 MPa).The stress value of enamel and dental under the oblique load was greater than that under vertical load.Conclusion The use of modeling approach of CBCT scan combined with reverse engineering software Mimics and Geomagic, modeling software,the finite element analysis software ANSYS workbench was fast feasible.And the model had the favourable similarities of geometric and biomechanics.