Abstract Computational models of the masticatory system can provide estimates of occlusal loading during (static) biting or (dynamic) chewing and therefore can be used to evaluate and optimize functional performance of prosthodontic devices and guide dental surgery planning. The modelling assumptions, however, need to be chosen carefully in order to obtain meaningful predictions. The objectives of this study were two-fold: (i) develop a computational model to calculate the stress response of the first molar during biting of a rubber sample and (ii) evaluate the influence of different occlusal load models on the stress response of dental structures. A three-dimensional finite element model was developed comprising the mandible, first molar, associated dental structures, and the articular fossa and discs. Simulations of a maximum force bite on a rubber sample were performed by applying muscle forces as boundary conditions on the mandible and computing the contact between the rubber and molars (GS case). The molar occlusal force was then modelled as a single point force (CF1 case), four point forces (CF2 case), and as a sphere compressing against the occlusal surface (SL case). The peak enamel stress for the GS case was 110 MPa and 677 MPa, 270 MPa and 305 MPa for the CF1, CF2 and SL cases, respectively. Peak dentin stress for the GS case was 44 MPa and 46 MPa, 50 MPa and 63 MPa for the CF1, CF2 and SL cases, respectively. Furthermore, the enamel stress distribution was also strongly correlated to the occlusal load model. The way in which occlusal load is modelled has a substantial influence on the stress response of enamel during biting, but has relatively little impact on the behavior of dentin. The use of point forces or sphere contact to model occlusal loading during mastication overestimates enamel stress magnitude and also influences enamel stress distribution.

中文翻译：

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咬合负荷建模显着影响咬合期间预测的牙齿应力响应：模拟研究

摘要 咀嚼系统的计算模型可以估计（静态）咬合或（动态）咀嚼期间的咬合负荷，因此可用于评估和优化修复装置的功能性能并指导牙科手术计划。然而，需要仔细选择建模假设以获得有意义的预测。本研究的目的有两个：(i) 开发一个计算模型来计算咬合橡胶样品期间第一磨牙的应力响应和 (ii) 评估不同咬合负载模型对牙齿应力响应的影响结构。开发了一个三维有限元模型，包括下颌骨、第一磨牙、相关的牙齿结构以及关节窝和椎间盘。通过在下颌骨上应用肌肉力作为边界条件并计算橡胶和臼齿之间的接触（GS 案例），对橡胶样品上的最大咬合力进行模拟。然后将磨牙咬合力建模为单点力（CF1 情况）、四点力（CF2 情况）和一个球体压缩咬合面（SL 情况）。对于 CF1、CF2 和 SL 情况，GS 外壳的峰值搪瓷应力分别为 110 MPa 和 677 MPa、270 MPa 和 305 MPa。对于 CF1、CF2 和 SL 病例，GS 病例的牙本质峰值应力分别为 44 MPa 和 46 MPa、50 MPa 和 63 MPa。此外，牙釉质应力分布也与咬合负荷模型密切相关。咬合负荷的建模方式对咬合过程中牙釉质的应力反应有重大影响，但对牙本质的行为影响相对较小。在咀嚼过程中使用点力或球体接触来模拟咬合负荷会高估牙釉质应力大小，也会影响牙釉质应力分布。