The periodontal ligament (PDL) is a porous and fibrous soft tissue situated around the tooth, which plays a key role in the transmission of loads from the tooth to the alveolar bone of the mandible. Although several studies have tried to characterize its mechanical properties, the behaviour of this tissue is not clear yet. In this study, a new simulation methodology based on a material model which considers the contribution of porous and fibrous structure with different material model formulations depending on the effort direction is proposed. The defined material model was characterized by a non-linear approximation of the porous fibrous matrix to experimental results obtained from samples of similar species and was validated by rigorous test simulations under tensile and compressive loads. The global PDL response was also validated using the parameters of the characterization in a finite element model of full human canine tooth obtained by micro-tomography. The results suggest that the porous contribution has high influence during compression because the bulk modulus of the material depends on the ability of interstitial fluid to drain. On the other hand, the collagen fibres running along the load direction are the main responsible of the ligament stiffness during tensile efforts. Thus, a material model with distinct responses depending of the load direction is proposed. Furthermore, the results suggest the importance of considering 3D finite element models based of the real morphology of human PDL for representing the irregular stress distribution caused by the coupling of complex material models and irregular morphologies.

牙周膜（PDL）是位于牙齿周围的多孔且纤维状的软组织，在负荷从牙齿到下颌骨的牙槽骨的传递中起着关键作用。尽管一些研究试图表征其机械性能，但该组织的行为尚不清楚。在这项研究中，提出了一种新的基于材料模型的模拟方法，该方法考虑了根据作用力方向不同材料模型配方的多孔和纤维结构的贡献。定义的材料模型的特征是，多孔纤维基体与相似物种样品的实验结果呈非线性近似，并通过在拉伸和压缩载荷下的严格测试模拟进行了验证。还使用微断层摄影术获得的完整人类犬齿的有限元模型中的特征参数验证了全局PDL响应。结果表明，多孔材料在压缩过程中具有较高的影响，因为材料的体积模量取决于间隙流体的排泄能力。另一方面，沿载荷方向延伸的胶原纤维是拉伸过程中韧带刚度的主要原因。因此，提出了一种根据载荷方向具有不同响应的材料模型。此外，结果表明考虑基于人类PDL真实形态的3D有限元模型对于表示由复杂材料模型和不规则形态耦合引起的不规则应力分布的重要性。