Mosharraf Ramin, Abbasi Mahsa, Givehchian Pirooz
Dental Material Research Center and Department of Prosthodontics, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Department of Prosthodontics, School of Dentistry, Shahrekord University of Medical Sciences, Shahrekord, Iran.
Int J Dent. 2022 Aug 27;2022:4451810. doi: 10.1155/2022/4451810. eCollection 2022.
The aim of this study was to evaluate influence of abutment angulation and restoration material compositions on the stress pattern in dental implants and their surrounding bone.
In this finite element study, the six different solid 3D models of "mandibular 3-unit fixed implant-supported prostheses" were analyzed. In all of these models, a straight abutment was used for anterior implants at the second premolar site, and in order to posterior implant at the second molar site, abutments with three different angles (straight, 15, and 20°) were used. Also, two different restoration material compositions (porcelain fused to base metal (PFBM) and porcelain fused to noble metal (PFNM)) were considered for fixed implant supported restorations. A 450 N static force was exerted in a straight manner along the longitudinal axis of the anterior implant in a tripod, and the stress distribution was measured based on the restoration materials and abutment angulations of the models in the 3 sites of cortical, cancellous bone, and fixtures. The simulation was performed with ABAQUS 6.13 Software.
In all models, stress values in surrounding cortical bone were more than in spongy bone. Maximum stress levels in an anterior abutment-implant complex were seen in models with angled implants. In models with parallel implants, the stress level of a molar straight abutment-implant complex was less than that of premolar straight ones. In an angled posterior abutment-implant complex, less stress level was detected compared to straight ones. In all PFNB models, stress values were slightly more and distributed in a wider area of premolar straight abutments.
Increasing an abutment angle, increases stress in surrounding bone and straight implant-abutment combination. It seems that the crown material composition affects stress distribution of the implant-abutment combination but does not affect stress distribution of surrounding bone.
本研究旨在评估基台角度和修复材料成分对牙种植体及其周围骨组织应力模式的影响。
在这项有限元研究中，分析了6个不同的“下颌3单位固定种植体支持义齿”实体三维模型。在所有这些模型中，第二前磨牙部位的前牙种植体使用直基台，而第二磨牙部位的后牙种植体则使用三种不同角度（直、15°和20°）的基台。此外，对于固定种植体支持的修复体，考虑了两种不同的修复材料成分（贱金属烤瓷（PFBM）和贵金属烤瓷（PFNM））。在一个三脚架中，沿前牙种植体长轴以直线方式施加450 N的静力，并根据模型在皮质骨、松质骨和种植体三个部位的修复材料和基台角度测量应力分布。使用ABAQUS 6.13软件进行模拟。
在所有模型中，周围皮质骨的应力值均高于松质骨。在前牙基台-种植体复合体中，角度种植体模型的应力水平最高。在平行种植体模型中，磨牙直基台-种植体复合体的应力水平低于前磨牙直基台-种植体复合体。在角度后牙基台-种植体复合体中，与直基台相比，应力水平较低。在所有PFNB模型中，前磨牙直基台的应力值略高且分布在更广泛的区域。
增加基台角度会增加周围骨组织和直种植体-基台组合中的应力。似乎冠修复材料成分会影响种植体-基台组合的应力分布，但不会影响周围骨组织的应力分布。
