The Effect of Platform-Switching Implants and Different Abutment Materials on the Stress Distribution of Implant-Supported Restorations

The purpose of this study was to evaluate the effect of implant platformswitching design and abutment materials on the stress distribution around implants. Implants were fixed in epoxy-resin models restoring posterior missing first molars, representing two main groups according to the implant-abutment connection. Each group was subdivided according to the type of abutment material used (titanium or zirconia). Twenty monolithic fully anatomical zirconia crowns were fabricated. Stress analysis was measured around the implants using strain gauges during the static loading of each implant-supported crown. Data were collected, tabulated, and statistically analyzed. Standard implant-abutment connection groups recorded the highest (statistically significant; P .05) mean strain values compared to platform-switching connection groups. Abutment materials in both groups recorded statistically nonsignificant (P > .05) mean strain values. The platform-switching concept showed better crestal-bone stress distribution around implant-supported restorations. Abutment materials expressed no statistically significant effect on the stress distribution around implant-supported restorations. Zirconia and titanium abutments could withstand the functional loads developed during physiologic chewing in the molar area.