Wiest Wolfram, Rack Alexander, Zabler Simon, Schaer Alex, Swain Michael, Nelson Katja
Chair for X-Ray Microscopy, University Würzburg, Josef-Martin Weg 63, 97074 Würzburg, Germany.
The European Synchrotron, CS 40220, 38043 Grenoble Cedex 9, France.
Heliyon. 2018 Feb 8;4(2):e00524. doi: 10.1016/j.heliyon.2018.e00524. eCollection 2018 Feb.
State-of-the art, two-piece dental implants made from titanium alloys exhibit a complex micromechanical behavior under dynamical load. Its understanding, especially the formation of microgaps, is of crucial importance in order to predict and improve the long-term performance of such implants. Microgap formation in a loaded dental implant with a conical implant-abutment connection can be studied and quantified by synchrotron radiography with micrometer accuracy. Due to the high costs and limited access to synchrotron radiation sources, alternative approaches are needed in order to depict the microgap formation. Therefore, synchrotron radiography is used in this article to validate a simple finite element model of an experimental conical implant design. Once validated, the model is in turn employed to systematically study the microgap formation developed in a variety of static load scenarios and the influence of the preload of abutment screw on the microgap formation. The size of the microgap in finite element analysis (FEA) simulations is consistent with that found in experiments. Furthermore, the FE approach gives access to more information such as the von-Mises stresses. It is found that the influence of the abutment screw preload has only a minor effect on the microgap formation and local stress distribution. The congruence between FE simulations and measurements at the micrometer scale underlines the validity and relevance of the simple FE method applied to study the micromovement of the abutment and the abutment screw preload in conical implant-abutment connections under load.
由钛合金制成的先进两件式牙种植体在动态载荷下表现出复杂的微观力学行为。了解其行为，尤其是微间隙的形成，对于预测和改善此类种植体的长期性能至关重要。对于带有锥形种植体-基台连接的加载牙种植体中的微间隙形成，可以通过具有微米精度的同步辐射成像进行研究和量化。由于同步辐射源成本高昂且获取受限，因此需要其他方法来描述微间隙的形成。因此，本文使用同步辐射成像来验证一个实验性锥形种植体设计的简单有限元模型。一旦验证，该模型反过来用于系统地研究在各种静态载荷情况下形成的微间隙以及基台螺钉预紧力对微间隙形成的影响。有限元分析（FEA）模拟中的微间隙大小与实验中发现的一致。此外，有限元方法可以获取更多信息，如冯·米塞斯应力。研究发现，基台螺钉预紧力对微间隙形成和局部应力分布的影响较小。有限元模拟与微米级测量之间的一致性强调了应用简单有限元方法研究加载状态下锥形种植体-基台连接中基台和基台螺钉预紧力微观运动的有效性和相关性。
