Postdoctoral Fellow, Medical Device Innovation Center, National Cheng Kung University, Tainan City, Taiwan ROC.
Professor, Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan ROC; Professor, Medical Device Innovation Center, National Cheng Kung University, Tainan City, Taiwan ROC.
J Prosthet Dent. 2022 Apr;127(4):601-608. doi: 10.1016/j.prosdent.2020.10.022. Epub 2020 Dec 19.
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.
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.
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.
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.
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.
压配（莫氏锥度）种植体系统常用于修复无牙颌区域。然而，由于该系统的 2 或 3 部分设计，基台螺丝可能会损坏，从而导致并发症。这些损坏情况是如何发生的尚不清楚。
本体外和有限元分析（FEA）研究的目的是阐明基台螺丝损坏的压配种植体系统的机制。
ANKYLOS 种植体系统被用作模拟模型和实验试件。通过材料测试系统进行了实验测试，获得的数据用于验证 FEA 结果。在 FEA 模拟中，采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丝的过程。然后在基台上施加 300N 的力，以研究种植体系统的应力分布和变形。
在实验测试中，所有试件的断裂部位均观察到在基台螺丝螺纹处。所有的种植体和基台都表现出永久弯曲变形。FEA 模拟的结果与实验结果基本一致。
用于在基台和种植体之间产生压配接触界面的基台扭矩会在种植体组件内产生应力，这大大增加了锥形种植体系统在功能过程中的失效概率。
