Evaluation of long-term implant success.

Implant success criteria, regarding marginal bone loss and other parameters, were first suggested in 1986 and today are still frequently referred to as the gold standard for implant success. However, according to the recent abundance of data on marginal bone loss and a better understanding of bone and soft tissue behavior around the implant neck and body, these criteria are inaccurate for the wide variety of implant systems. The purpose of this article is to review some of the relevant literature regarding marginal bone loss and to propose guidelines for a novel approach to evaluate the long-term success of implants regarding marginal bone loss. Four hypothetical patterns of implant marginal bone loss after the first year are suggested: a low-rate marginal bone loss over the years (Albrektsson's pattern); low-rate marginal bone loss in the first few years followed by a rapid loss of bone support; high-rate marginal bone loss in the first few years followed by almost no bone loss; and continuous high-rate marginal bone loss leading to a complete loss of bone support.