Effect of platform switching on implant crest bone stress: a finite element analysis

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.