Abstract: Objective To establish a three-dimensional finite element model of a mandibular first molar with single and combined crown after separation prosthodontic therapy for biomechanical analysis of crown prosthesis. Methods The 3-D finite element model was established with CBCT scanning method. Mimics software was used to read and deal with the tomography data preliminarily, Geomagic software was for precise modification, and UG software was utilized to assemble all of the modules and Ansys software to divide gridding. Result The 3-D finite element models of the mandibular first molar with normal structure and the molar treated with separation prosthodontic therapy were established. Conclusions It was feasible, fast and effective to use the modeling approach of CBCT scan combined with reverse engineering software Mimics and Geomagic, modeling software UG, the finite element analysis software Ansys to establish the 3D finite element model.

Key words: separating root, 3D finite element method, single crown, combined crown, mandibular first molar