Schrotenboer Jason, Tsao Yi-Pin, Kinariwala Vipul, Wang Hom-Lay
School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA.
Implant Dent. 2009 Jun;18(3):260-9. doi: 10.1097/ID.0b013e31819e8c1d.
The purpose of this study was to investigate, in a model, the interaction phenomena of platform switching on the trans-cortical section of bone adjacent to an endosseous dental implant.
A 2-dimensional finite element model was fabricated to analyze the bone-implant interactions under masticatory forces. Two abutment diameters, 4.5 mm representing platform switching and 5 mm representing a standard platform, were used in conjunction with a 5-mm diameter fixture. A 100-N static force was applied vertically (90 degrees) and obliquely (15 degrees) to the abutments. All models were obtained using a reverse engineering process with values obtained from other studies to create a hypothetical implant system that demonstrates basic implant features.
The standard platform model demonstrated a maximum crestal Von-Mises stress of 28 and 6.977 MPa under oblique and vertical load-ing, respectively. The platform switching model showed 27.43 and 6.502 MPa under oblique and vertical loading, respectively. This implies that a 10% reduction in abutment diameter results in a 2.04% and 6.81% decrease under oblique and vertical loading, respectively, in Von-Mises stress. The distribution pattern of forces was minimally altered between both abutment models, with a slightly more significant change in the vertical loading scenario.
Results from this study showed the reduction of abutment diameter (i.e., platform switching) resulted in a measurable but minimal effect on Von-Mises stress in the crestal region of cortical bone. However, future clinical trials in this area are warranted before any firm conclusion is drawn.
本研究旨在通过模型研究平台转换在骨内牙种植体相邻皮质骨跨皮质部分上的相互作用现象。
制作二维有限元模型以分析咀嚼力作用下的骨-种植体相互作用。使用两种基台直径，4.5毫米代表平台转换，5毫米代表标准平台，与5毫米直径的种植体一起使用。向基台垂直（90度）和倾斜（15度）施加100牛的静力。所有模型均采用逆向工程过程获得，其数值取自其他研究，以创建一个展示基本种植体特征的假设种植系统。
标准平台模型在倾斜和垂直加载下的最大嵴顶冯·米塞斯应力分别为28和6.977兆帕。平台转换模型在倾斜和垂直加载下分别显示为27.43和6.502兆帕。这意味着基台直径减小10%会导致在倾斜和垂直加载下冯·米塞斯应力分别降低2.04%和6.81%。两种基台模型之间力的分布模式变化极小，在垂直加载情况下变化稍大。
本研究结果表明，基台直径减小（即平台转换）对皮质骨嵴顶区域的冯·米塞斯应力有可测量但极小的影响。然而，在得出任何确切结论之前，该领域未来的临床试验是必要的。
