PDF(Pubmed)
Abstract：
The long-term success and predictability of implant-supported restorations largely depends on the biomechanical forces (stresses) acting on implants and the surrounding alveolar bone in the mandible. The aim of our study was to investigate the biomechanical behavior of an edentulous mandible with an implant-supported full bridge on four implants under simulated masticatory forces, in the context of different loading schemes, using a three-dimensional finite element analysis (3D-FEA). A patient-specific 3D finite element model was constructed using pre- and post-implantation computer tomography (CT) images of a patient undergoing implant treatment. Simplified masticatory forces set at 300 N were exerted vertically on the denture in four different simulated load cases (LC1-LC4). Two sets of simulations for different implants and denture materials (S1: titanium and titanium; S2: titanium and cobalt-chromium, respectively) were made. Stress outputs were taken as maximum (Pmax) and minimum principal stress (Pmin) and equivalent stress (Peqv) values. The highest peak Pmax values were observed for LC2 (where the modelled masticatory force excluded the cantilevers of the denture extending behind the terminal implants), both regarding the cortical bone (S1 Pmax: 89.57 MPa, S2 Pmax: 102.98 MPa) and trabecular bone (S1 Pmax: 3.03 MPa, S2 Pmax: 2.62 MPa). Overall, LC1-where masticatory forces covered the entire mesio-distal surface of the denture, including the cantilever-was the most advantageous. Peak Pmax values in the cortical bone and the trabecular bone were 14.97-15.87% and 87.96-94.54% higher in the case of S2, respectively. To ensure the long-term maintenance and longevity of treatment for implant-supported restorations in the mandible, efforts to establish the stresses of the surrounding bone in the physiological range, with the most even stress distribution possible, have paramount importance.
摘要：
植入物支持的修复体的长期成功和可预测性在很大程度上取决于作用在植入物和下颌骨周围牙槽骨上的生物力学力（应力）。我们研究的目的是研究在模拟咀嚼力下，在四个植入物上具有植入物支撑的全桥的无牙下颌骨的生物力学行为，在不同的加载方案的背景下，使用三维有限元分析(3D-FEA)。使用接受植入物治疗的患者的植入前和植入后计算机断层摄影（CT）图像构建患者特定的3D有限元模型。在四种不同的模拟载荷情况下（LC1-LC4），将简化的咀嚼力设置为300N垂直施加在义齿上。两组不同种植体和义齿材料的模拟（S1：钛和钛；S2：钛和钴铬，分别)。应力输出取最大(Pmax)和最小主应力(Pmin)和等效应力(Peqv)值。对于LC2观察到最高峰Pmax值（其中模拟的咀嚼力排除了延伸在末端植入物后面的义齿的悬臂），两者都关于皮质骨(S1Pmax：89.57MPa，S2Pmax：102.98MPa）和小梁骨（S1Pmax：3.03MPa，S2Pmax:2.62MPa)。总的来说,LC1-咀嚼力覆盖了义齿的整个中远端表面，包括悬臂-是最有利的。在S2的情况下，皮质骨和小梁骨的峰值Pmax值分别高14.97-15.87％和87.96-94.54％。为了确保下颌骨种植体支撑修复体的长期维护和治疗寿命，努力在生理范围内建立周围骨骼的应力，具有尽可能均匀的应力分布，具有至高无上的重要性。
