Objective:To investigate the influences of material properties and damping effect on the dynamic response analysis of human periodontal ligament. Methods: A 3-D finite element model of human teeth and periodontal tissue was built from graphic information obtained by CT scanning. Dynamic analysis was performed to investigate the influence of different damping effects on the stresses of periodontal ligament by the finite element method. Results: (a) No significant difference of stress between small and large deformation assumption was found, the variation was no more than 1.4%.(b) Dynamic response was obtained under ? varies from 0 to 1.2. After one mastication period, the residual stress at interior surface was larger than that at exterior surface, with a maximum value of ? r = 0.34 MPa at labial cervical area. Conclusion: Appropriate assumptions on material properties may reduce the cost of analysis. After one mastication period, some levels of residual stresses are in periodontal ligament and influenced by material damp.

Objective:To improve stress analysis in stress-intensive regions of human periodontal tissue. Methods:Based on coarse analysis on the finite element(FE) model including human teeth and periodontal tissue, the submodel method was introduced to analyze the stresses in interested region such as apical. Results:Submodel analysis showed same stress distribution as FE model while more precision of stress value was obtained by submodel because refined mesh was used.Conclusion:More accurate stresses measurements in local regions can be obtained by submodel method.