The most definitive criterion is that the implant is not mobile.By definition,osseointegration produces a direct structural and functional union between the surrounding bone and the surface of the implant.The implant is therefore held rigidly within bone without an intervening fibrous encapsulation(or periodontal ligament) and therefore should not exhibit any mobility or peri-implant radiolucency.

    Implants placed in the mandible(particularly anterior to the mental foramina) enjoy a very high success rate,such that it would be difficult or impossible to show differences between rival systems.In contrast,the more demanding situation of the posterior maxilla,where implants of shorter length are placed in bone of softer quality,may reveal differences between success rates.This remains to be substantiated in comparative clinical.Currently,there are no comparative data to recommended one system over another,but certain design feature may have theoretical advantages.