The influences on the stress distributions of the alveolar tissues by the different material properties of enamel and pulp 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; however 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.
