Construcion of a three-dimensional finite element model of a cracked maxillary first molar by using solid modeling method

YIN Xiao; ZHANG Ya-Qing; HOU Lei; HAN Bing

Abstract：AIM: To construct a three-dimensional finite element model of a cracked maxillary first molar by the solid crack modeling method. METHODS: An intact first maxillary molar was scanned with micro-CT. After pictures of every cross-section were adjusted,surface contours of enamel and dentin were fitted following tooth segmentation based on different gray scale using an interactive medical image control system (MIMICS). Then enamel and dentin were separately converted into stereolithography files which were consisted of the nodal points and surfaces information. A stereolithography handling software (MAGICS) was used to reestablish the congruence of the interfacial mesh between enamel and dentin. Then the remesh operations were applied to the STL model to improve the quality of the triangles. These high quality STL files were imported into finite element analysis software. The crack part was established on the entire model to accomplish the modeling. The crack part was meshed with particular method based on fracture mechanical theory by using singular element,and an initial analysis was taken to testify the dependability of the model.RESULTS: A refined three-dimensional finite element model of a cracked first maxillary molar was constructed and meshes of the crack could reflect the stress singularities in crack-tip. CONCLUSION :The solid modeling method is simple and efficient and can be carried on easily. It is suitable to establish a cracked tooth model for crack growth analysis.