Statement of problem

The press-fit (Morse taper) implant system is commonly used to restore edentulous areas. However, abutment screws in this system may be damaged because of the 2- or 3-piece design, consequently causing complications. How these damaging situations occur is unclear.

Purpose

The purpose of this in vitro and finite element analysis (FEA) study was to elucidate the mechanisms of the press-fit implant system underlying abutment screw damage.

Material and methods

The ANKYLOS implant system was used as a simulation model and for experimental test specimens. The experimental test was performed by using a material test system, and the obtained data were used to validate the FEA outcome. In the FEA simulation, the bilinear material property and nonlinear contact conditions were applied to simulate the process of tightening the abutment screw between the abutment and implant. A force of 300 N was then applied to the abutment to investigate the stress distribution and deformation of the implant system.

Results

In the experimental test, the fracture site of all specimens was observed at the abutment-screw thread. All implants and abutments exhibited permanent bending deformation. The results of the FEA simulation generally concurred with the experimental outcomes.

Conclusions

The abutment torque used to generate the press-fit contact interface between the abutment and implant induced stresses within the implant components, substantially increasing the failure probability of the conical implant system during function.

中文翻译：

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通过体外实验测试和有限元分析对锥形莫氏锥度种植体系统中的压配效应进行生物力学分析

问题陈述

压配（莫氏锥度）种植系统通常用于修复缺牙区。但是，该系统中的基台螺钉可能会因为 2 件或 3 件式设计而损坏，从而导致并发症。这些破坏性情况如何发生尚不清楚。

目的

这项体外和有限元分析 (FEA) 研究的目的是阐明压配种植体系统在基台螺钉损伤下的机制。

材料与方法

ANKYLOS 种植体系统被用作模拟模型和实验测试样本。使用材料测试系统进行实验测试，获得的数据用于验证有限元分析结果。在 FEA 模拟中，应用双线性材料特性和非线性接触条件来模拟在基台和种植体之间拧紧基台螺钉的过程。然后向基台施加 300 N 的力，以研究种植体系统的应力分布和变形。

结果

在实验测试中，所有试样的断裂部位都在基台螺纹处观察。所有种植体和基台都表现出永久弯曲变形。FEA 模拟的结果通常与实验结果一致。

结论

用于在基台和种植体之间产生压配合接触界面的基台扭矩会在种植体部件内引起应力，从而显着增加锥形种植体系统在功能期间的失效概率。