Yao Kuang-Ta, Chen Chen-Sheng, Cheng Cheng-Kung, Fang Hsu-Wei, Huang Chang-Hung, Kao Hung-Chan, Hsu Ming-Lun
1 Department of Dentistry, National Yang-Ming University, Taipei, Taiwan.
2 Institute of Rehabilitation Science and Technology, National Yang-Ming University, Taipei, Taiwan.
J Oral Implantol. 2018 Feb;44(1):26-35. doi: 10.1563/aaid-joi-D-17-00149. Epub 2017 Nov 1.
Conical implant-abutment connections are popular for their excellent connection stability, which is attributable to frictional resistance in the connection. However, conical angles, the inherent design parameter of conical connections, exert opposing effects on 2 influencing factors of the connection stability: frictional resistance and abutment rigidity. This pilot study employed an optimization approach through the finite element method to obtain an optimal conical angle for the highest connection stability in an Ankylos-based conical connection system. A nonlinear 3-dimensional finite element parametric model was developed according to the geometry of the Ankylos system (conical half angle = 5.7°) by using the ANSYS 11.0 software. Optimization algorithms were conducted to obtain the optimal conical half angle and achieve the minimal value of maximum von Mises stress in the abutment, which represents the highest connection stability. The optimal conical half angle obtained was 10.1°. Compared with the original design (5.7°), the optimal design demonstrated an increased rigidity of abutment (36.4%) and implant (25.5%), a decreased microgap at the implant-abutment interface (62.3%), a decreased contact pressure (37.9%) with a more uniform stress distribution in the connection, and a decreased stress in the cortical bone (4.5%). In conclusion, the methodology of design optimization to determine the optimal conical angle of the Ankylos-based system is feasible. Because of the heterogeneity of different systems, more studies should be conducted to define the optimal conical angle in various conical connection designs.
锥形种植体-基台连接因其出色的连接稳定性而广受欢迎，这种稳定性归因于连接中的摩擦阻力。然而，锥角作为锥形连接的固有设计参数，对连接稳定性的两个影响因素具有相反的作用：摩擦阻力和基台刚性。这项初步研究采用有限元法的优化方法，以在基于Ankylos的锥形连接系统中获得最高连接稳定性的最佳锥角。使用ANSYS 11.0软件，根据Ankylos系统的几何形状（锥半角 = 5.7°）建立了非线性三维有限元参数模型。进行优化算法以获得最佳锥半角，并使基台中最大von Mises应力的最小值达到最小，这代表最高的连接稳定性。获得的最佳锥半角为10.1°。与原始设计（5.7°）相比，优化设计显示基台刚性增加（36.4%），种植体刚性增加（25.5%），种植体-基台界面处的微间隙减小（62.3%），接触压力降低（37.9%），连接中的应力分布更均匀，皮质骨中的应力降低（4.5%）。总之，通过设计优化来确定基于Ankylos系统的最佳锥角的方法是可行的。由于不同系统的异质性，应进行更多研究以确定各种锥形连接设计中的最佳锥角。
