Effect of Platform Switching on Implant Crest Bone Stress: A Finite Element Analysis

Objectives: 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. Materials: 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. Results: The standard platform model demonstrated a maximum crestal Von-Mises stress of 28 and 6977 MPa under oblique and vertical loading, 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. Conclusions: 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 arc, warranted before any firm conclusion is drawn. (Implant Dent 2009;18:260-269)