Department of Dental materials and Prosthodontics, Araçatuba Dental School, São Paulo State University, São Paulo, Brazil.
Int J Oral Maxillofac Implants. 2009 Nov-Dec;24(6):1040-4.
This study aimed to evaluate the influence of implants with or without threads representation on the outcome of a two-dimensional finite element (FE) analysis.
Two-dimensional FE models that reproduced a frontal section of edentulous mandibular posterior bone were constructed using a standard crown/implant/screw system representation. To evaluate the effect of implant threads, two models were created: a model in which the implant threads were accurately simulated (precise model) and a model in which implants with a smooth surface (press-fit implant) were used (simplified model). An evaluation was performed on ANSYS software, in which a load of 133 N was applied at a 30-degree angulation and 2 mm off-axis from the long axis of the implant on the models. The Von Mises stresses were measured.
The precise model (1.45 MPa) showed higher maximum stress values than the simplified model (1.2 MPa). Whereas in the cortical bone, the stress values differed by about 36% (292.95 MPa for the precise model and 401.14 MPa for the simplified model), in trabecular bone (19.35 MPa and 20.35 MPa, respectively), the stress distribution and stress values were similar. Stress concentrations occurred around the implant neck and the implant apex.
Considering implant and cortical bone analysis, remarkable differences in stress values were found between the models. Although the models showed different absolute stress values, the stress distribution was similar.
本研究旨在评估具有或不具有螺纹结构的种植体对二维有限元（FE）分析结果的影响。
使用标准的牙冠/种植体/螺钉系统模型，构建了再现无牙下颌后骨额部的二维 FE 模型。为了评估种植体螺纹的影响，构建了两个模型：一个是准确模拟种植体螺纹的模型（精确模型），另一个是使用具有光滑表面的种植体（压配种植体）的模型（简化模型）。在 ANSYS 软件中进行了评估，在模型上以 30 度角和离种植体长轴 2 毫米的位置施加 133 N 的载荷。测量 Von Mises 应力。
精确模型（1.45 MPa）的最大应力值高于简化模型（1.2 MPa）。在皮质骨中，应力值差异约为 36%（精确模型为 292.95 MPa，简化模型为 401.14 MPa），而在松质骨中（分别为 19.35 MPa 和 20.35 MPa），应力分布和应力值相似。应力集中发生在种植体颈部和种植体尖端周围。
考虑到种植体和皮质骨的分析，两个模型之间的应力值存在显著差异。尽管模型显示了不同的绝对应力值，但应力分布相似。
