Department of Periodontics, College of Dentistry, Gulf Medical University, Ajman, UAE.
Department of Periodontics, Rajah Muthiah Dental College and Hospital, Annamalai, Chidambaram, Tamil Nadu, India.
Niger J Clin Pract. 2021 May;24(5):660-666. doi: 10.4103/njcp.njcp_362_20.
To investigate the effect of platform switched short dental implants and subcrestal placement on von Mises stress in the maxillary anterior region (D3 bone) by using three-dimensional finite element model analyses (3D FEM).
Biomechanical behaviour of von Mises stress in maxillary anterior region (D3) bone were stimulated with the help of 3D FEM with the help of ANSYS WORKBENCH version 17.5. The bone model had a cortical core of (1 mm) surrounding the inner cancellous core, which represents D3 bone. Two models were designed model 1 (6 x 4.6 mm), (7.5 x 4.6 mm) and model 2 (6 x 5.8 mm), (7.5 x 5.8 mm). Loads of 100, 200 N were applied at an angle of 0°, 15°, 30° along the long axis of the tooth model.
In all model's cortical bone exhibited greater stress than cancellous bone. Greater stress was reported in axial direction at 30° then 15° and least at 0° irrespective of load applied. An increase in implant length (7.5 mm) did not exhibit any stress reduction in both the model but implant diameter (5.8 mm) led to reduction in von Mises stress in both the groups. Greater the force applied greater was stress in both bones irrespective of direction of force applied (200N). Lastly subcrestal (0.5 mm) placement has slight reduction in stress compared to equicrestal placement in both the groups.
Numerical results from the current study suggest that, for short implants, implant diameter is considered more effective design parameter than implant length. Current findings state that platform switch short subcrestal implants results in conservation of marginal bone loss along with better stress distribution around peri-implant regions in D3 bone. However, all models analyzed in this study showed development of von Mesies stresses within physiological limits for human cortical bone.
通过三维有限元模型分析（3D FEM）研究平台转换短种植体和骨下种植对上颌前区（D3 骨）von Mises 应力的影响。
借助 ANSYS WORKBENCH 版本 17.5 的三维有限元模型分析，刺激上颌前区（D3）骨的 von Mises 应力生物力学行为。骨模型具有围绕内部松质骨核心的皮质核心（1 毫米），代表 D3 骨。设计了两种模型：模型 1（6 x 4.6 毫米），（7.5 x 4.6 毫米）和模型 2（6 x 5.8 毫米），（7.5 x 5.8 毫米）。在沿牙模型长轴的 0°、15°和 30°的角度施加 100、200 N 的载荷。
在所有模型中，皮质骨的应力均大于松质骨。在轴向方向上，在 30°时报告的应力大于在 15°时，在 0°时最小，而与施加的载荷无关。在两种模型中，增加种植体长度（7.5 毫米）并没有导致任何应力减小，但种植体直径（5.8 毫米）导致两组的 von Mises 应力减小。施加的力越大，两种骨中的应力越大，而与施加力的方向无关（200N）。最后，与平台平齐种植相比，骨下（0.5 毫米）种植导致两组的应力略有减小。
当前研究的数值结果表明，对于短种植体，种植体直径被认为是比种植体长度更有效的设计参数。当前的研究结果表明，平台转换短骨下种植体可保留边缘骨丢失，同时改善 D3 骨周围种植体区域的应力分布。然而，本研究分析的所有模型均显示出人类皮质骨的 von Mesies 应力在生理范围内的发展。
