Tribst João Paulo M, de Jager Niek, Dal Piva Amanda M O, Kleverlaan Cees J, Feilzer Albert
Academic Centre for Dentistry Amsterdam (ACTA), Department of Department of Reconstructive Oral Care, Universiteit van Amsterdam en Vrije Universiteit Amsterdam, 1081, LA, Amsterdam, the Netherlands.
Academic Centre for Dentistry Amsterdam (ACTA), Department of Dental Materials, Universiteit van Amsterdam en Vrije Universiteit Amsterdam, 1081, LA, Amsterdam, the Netherlands.
Heliyon. 2024 Mar 14;10(6):e28129. doi: 10.1016/j.heliyon.2024.e28129. eCollection 2024 Mar 30.
This study aimed to investigate the effect of four retention systems for implant-supported posterior crowns under compressive loading using three-dimensional finite element analysis. A morse-taper dental implant (4.1 × 10 mm) was designed with Computer Aided Design software based on non-uniform rational B-spline surfaces. According to International Organization for Standardization 14,801:2016, the implant was positioned at 3 mm above the crestal level. Then four models were designed with different crown retention systems: screw-retained (A), cement-retained (B), lateral-screw-retained (C), and modified lateral-screw-retained (D). The models were imported to the analysis software and mesh was generated based on the coincident nodes between the juxtaposed lines. For the boundary conditions, two loads (600 N) were applied (axial to the implant fixture and oblique at 30°) totaling 8 conditions according to retention design and loading. The von-Mises stress analysis showed that different retention systems modify the stress magnitude in the implant-supported posterior crown. There is a similar stress pattern in the implant threads. However, models C and D presented higher stress concentrations in the crown margin in comparison with A and B. The oblique loading highly increased the stress magnitude for all models. In the simulated conditions, part of the stress was concentrated at the lateral screw under axial loading for model C and oblique loading for model D. The results indicate a possible new failure origin for crown retained using lateral screws in comparison to conventional cement-retained or screw-retained systems.
本研究旨在通过三维有限元分析，研究四种固位系统对种植体支持的后牙冠在压缩载荷下的影响。使用基于非均匀有理B样条曲面的计算机辅助设计软件设计了一种莫氏锥度牙种植体（4.1×10mm）。根据国际标准化组织14801:2016，种植体位于牙槽嵴顶水平上方3mm处。然后设计了四种具有不同牙冠固位系统的模型：螺丝固位（A）、粘结固位（B）、侧向螺丝固位（C）和改良侧向螺丝固位（D）。将模型导入分析软件，并基于相邻线之间的重合节点生成网格。对于边界条件，根据固位设计和加载情况，施加两个载荷（600N）（一个轴向于种植体基台，另一个与轴向成30°斜向），共8种情况。冯·米塞斯应力分析表明，不同的固位系统会改变种植体支持的后牙冠中的应力大小。种植体螺纹中的应力模式相似。然而，与A和B相比，模型C和D在牙冠边缘处呈现出更高的应力集中。斜向加载使所有模型的应力大小大幅增加。在模拟条件下，对于模型C，部分应力在轴向加载时集中在侧向螺丝处；对于模型D，部分应力在斜向加载时集中在侧向螺丝处。结果表明，与传统的粘结固位或螺丝固位系统相比，使用侧向螺丝固位的牙冠可能存在新的失效起源。
