[Three dimensional finite element analysis of the influence of stress on occlusal surface of the mandibular first molar].

Purpose: Use of three-dimensional finite element to analyze stress distribution and transient displacement of mandibular first molar both at the occlusal surface level, to investigate the biomechanical basis of vertical root fracture occurring in the mesial root.

Methods: Mimics finite element software was used to build the horizontal and tilt abrasion of the mandibular first permanent molar. Each status was then divided into 4 kinds of wearing degree and 8 models were then established including sliced 1, sliced 2, sliced 3, sliced 4 and miter 5°,miter10°,miter15°,miter20° respectively.