Megha Chopra

New implant designs have appeared in the literature claiming that certain modifications may be helpful for maintaining crestal bone levels and consequently preserving normal soft tissue contours. In the late 1980s, wide diameter implants were commercially introduced. Initially, the implants were restored with standard-diameter abutments because of the lack of matching prosthetic components. Contrary to what was expected, post-loading radiographic evaluations showed no changes in the crestal bone levels around those implants. This serendipitous finding led to the introduction of the concept of Platform Switching, in which a smaller-diameter prosthetic component was connected to a larger-diameter implant platform to create an approximately 90 step between the implant and abutment. Several clinical reports demonstrate more favorable soft and hard tissue responses using implants placed with platform switching compared to standard platform-matched implants. Consequently, an increasing number of implant systems incorporated platform-switching into their designs as an innovative feature for preserving the peri-implant bone.

Researchers have attempted to explain the mechanism of action of platform switching; however, it is necessary to conduct further studies, including histological studies using animals, to clarify the mechanism fully. With respect to radiographic evaluations of crestal bone levels in humans, properly designed long- term observation is required, before establishing the long-term predictability of platform switching in preserving horizontal and vertical marginal bone levels or modifying the minimum distances between platform-switched implants and adjacent teeth or implants particularly through prospective, randomized, multicenter trials with large number of participants.