下颌前磨牙颈部硬组织非线性接触的应力分布有限元分析

Finite element contact stress analysis of the mandibular premolar cervix

目的:分析下颌前磨牙在不同载荷下牙颈部硬组织的应力分布。方法:建立上、下颌前磨牙釉质各向异性的二维有限元模型,模拟紧咬和咀嚼运动中牙齿的受力情况,对下颌前磨牙颈部硬组织进行非线性接触分析。结果:模拟正中咬合三点接触载荷时,颊、舌侧牙颈部釉质应力均最小,而模拟侧方运动工作侧一点接触载荷时,颊侧牙颈部釉质应力最大;侧方运动接触载荷下,牙颈部出现明显应力集中,颊、舌侧釉牙本质界区域是主要应力集中区。结论:牙颈部硬组织的应力与牙齿所受力的位置和方向密切相关。

Objective：To study the stress distribution of the mandibular premolar cervix during clenching and mastication. Methods：Models of anisotropic enamel of the mandibular first premolar and the opposite maxillary first premolar crown were establishied. The stress distributions in the cervical region of the mandibular premolar were investigated in different loading conditions： simulating working, nonworking and vertical micromotions. In each case, the stroke was applied to the maxillary first mandibular premolar in a stepping procedure using nonlinear contact analysis. Results：The stress in the cervical region under loading condition simulating vertical micromotion was lower than that under loading conditions simulating working and nonworking micromotions, The stress was mainly concentrated near the buccal or the lingual cervical enamelo-dentinal junction under loading conditions simulating lateral excursion. Conclusion： The stress distribution in the cervical region is closely related to the pattern of occlusal force including location and direction.