For a proper insight in the implant/tissue interface of permucosal oral implants it is good to refer to the tooth/periodontium interface. Although there are evident differences such as the lack of a periodontal ligament with its possibilities for eruption and migration and elaborate neural endings, it seems that classical periodontal parameters are the yardstick to discriminate failure from success of oral implants. Long cone radiographs and mobility assessment seem the only available clinical tools to detect a scar tissue interposition. On the other hand, their discrimination power is insufficient to prove close bone apposition. Further studies are needed to interpret the observations that around failing implants the subgingival microflora resembles that of active adult periodontitis. Periodontologists can learn a lot from the implant/periodontium interface to get a better understanding of the tooth/periodontium complex.