Zhou S M
Zhonghua Kou Qiang Yi Xue Za Zhi. 1989 Nov;24(6):334-7, 385.
Three-dimensional finite element analysis is used to determine the physiological stress values in periodontal ligament (PDL). In comparison with the elastic modulus E of PDL, the E of dentin and bone are much larger. For the estimation of the stresses in PDL, the tooth and the supporting bone can be considered to be rigid. The finite element model of PDL of the mandibular right first molar consists of 210 elements (20-node isoparametric element) and 1612 nodes. Eleven load cases were selected in the study, which included the longitudinal occlusive load, buccal lingual lateral load, mesial-distal lateral load and other load cases to simulate the actual occlusive loads. The results obtained from this study lead to the following conclusions: 1. The loads which go through the physiological center of the tooth, the stresses induced by the loads which are compressive and relatively small. There are no tensile stresses. 2. Among eleven load cases studied in this work, the following three load cases are most harmful. a. The maximum tensile stress was found under mesial-distal lateral load; b. The maximum compressive stress was found under longitudinal occlusive load on the buccal groove or lingual groove; c. The highest stress concentration was found under buccal-lingual lateral load. The clinical significance of the results has also been discussed in the paper.
采用三维有限元分析来确定牙周膜（PDL）中的生理应力值。与牙周膜的弹性模量E相比，牙本质和骨的弹性模量E要大得多。为了估算牙周膜中的应力，可以认为牙齿和支持骨是刚性的。下颌右侧第一磨牙牙周膜的有限元模型由210个单元（20节点等参单元）和1612个节点组成。本研究选取了11种载荷工况，包括纵向咬合载荷、颊舌向侧向载荷、近远中向侧向载荷以及其他载荷工况，以模拟实际咬合载荷。本研究得到的结果得出以下结论：1. 通过牙齿生理中心的载荷，由该载荷引起的应力为压缩性且相对较小。不存在拉应力。2. 在本研究的11种载荷工况中，以下三种载荷工况危害最大。a. 在近远中向侧向载荷下发现最大拉应力；b. 在颊沟或舌沟处的纵向咬合载荷下发现最大压应力；c. 在颊舌向侧向载荷下发现最高应力集中。本文还讨论了这些结果的临床意义。
