牙釉质和牙髓不同材料属性对牙周组织应力分布的影响

Effects of Different Material Properties of Enamel and Pulp on the Stress Distributions of the Alveolar Tissues

对比分析区分牙釉质和牙髓与否对牙周组织应力分布的影响,指导建模时是否考虑牙釉质和牙髓。选用正常形态的下颌中切牙,基于CT扫描建立3维有限元模型,所有结构都采用各自的材料属性,在此基础上,将牙釉质、牙髓分别考虑为和牙本质相同的材料属性,施加与5种典型正畸牙移动相对应的载荷,对3个模型在相同载荷作用下牙周组织的vonMises应力进行比较。结果表明,将牙本质的材料属性赋予牙釉质和牙髓导致牙根的最大应力差异分别为21.43%和9.25%,而对牙周膜和牙槽骨的计算结果几乎没有影响。当研究对象是牙体时,模型应区分牙釉质和牙髓;而当研究对象是牙周膜和牙槽骨时,则可不做区分。

The influences of different material properties of enamel and pulp on the stress distributions of the alveolar tissues were analyzed.A three-dimensional finite element model of the mandibular central incisor was constructed according to CT.The corresponding material properties were assigned to the alveolar tissues.Other two models were developed with the material properties of dentin assigned to enamel or pulp.The loads corresponding to bodily,intrusion,rotation,torque and tipping movements were applied to the three models.The von Mises stresses of the alveolar tissues of the three models were compared.The results showed that with the material properties of dentin assigned to enamel and pulp,the maximum stress differences of the roots were 21.43% and 9.25%,respectively,but the stresses of periodontal membrane and alveolar bone were hardly changed.When the stress distributions of teeth were studied,enamel and pulp should be modeled and assigned by the corresponding material properties.