de Moraes Sandra Lúcia Dantas, Verri Fellippo Ramos, Santiago Joel Ferreira, Almeida Daniel Augusto de Faria, de Mello Caroline Cantieri, Pellizzer Eduardo Piza
Discipline of Complete Denture, School of Dentistry of Pernambuco, UPE - University of Pernambuco, RecifePE, Brazil.
Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, UNESP - Univ Estadual Paulista, AraçatubaSP, Brazil.
Braz Dent J. 2013 Nov-Dec;24(6):635-41. doi: 10.1590/0103-6440201302287.
The purpose of this study was to assess the influence of the crown height of external hexagon implants on the displacement and distribution of stress to the implant/bone system, using the three-dimensional finite element method. The InVesalius and Rhinoceros 4.0 softwares were used to generate the bone model by computed tomography. Each model was composed of a bone block with one implant (3.75 x 10.0 mm) with external hexagon connections and crowns with 10 mm, 12.5 mm and 15 mm in height. A 200 N axial and a 100 N oblique (45°) load were applied. The models were solved by the NeiNastran 9.0 and Femap 10.0 softwares to obtain the results that were visualized by maps of displacement, von Mises stress (crown/implant) and maximum principal stress (bone). The crown height under axial load did not influence the stress displacement and concentration, while the oblique loading increased these factors. The highest stress was observed in the neck of the implant screw on the side opposite to the loading. This stress was also transferred to the crown/platform/bone interface. The results of this study suggest that the increase in crown height enhanced stress concentration at the implant/bone tissue and increased displacement in the bone tissue, mainly under oblique loading.
本研究的目的是采用三维有限元方法，评估外六角种植体的冠高度对种植体/骨系统应力位移和分布的影响。使用InVesalius和Rhinoceros 4.0软件通过计算机断层扫描生成骨模型。每个模型由一个带有一个种植体（3.75×10.0 mm）的骨块组成，该种植体具有外六角连接，以及高度分别为10 mm、12.5 mm和15 mm的牙冠。施加200 N的轴向载荷和100 N的斜向（45°）载荷。通过NeiNastran 9.0和Femap 10.0软件求解模型，以获得通过位移图、von Mises应力（牙冠/种植体）和最大主应力（骨）可视化的结果。轴向载荷下的冠高度不影响应力位移和集中，而斜向载荷会增加这些因素。在与加载相反一侧的种植体螺钉颈部观察到最高应力。该应力也传递到牙冠/平台/骨界面。本研究结果表明，冠高度的增加会增强种植体/骨组织处的应力集中，并增加骨组织中的位移，主要是在斜向载荷下。
