Long-term stability of osseointegrated implants in bone regenerated with the membrane technique. 5-year results of a prospective study with 12 implants.

The purpose of the present clinical study was to evaluate the 5-year results of the first 12 implants inserted at the University of Berne in regenerated bone following successful ridge augmentation with the membrane technique. The patients were recalled and examined with clinical and radiographic parameters routinely utilized in prospective studies with standard implants in non-regenerated bone. Based on clinical and radiographic findings, all 12 implants were considered successfully integrated according to strict criteria of success. The detailed analysis of clinical parameters revealed no differences to results of prospective studies on standard implants in non-regenerated bone. All implants demonstrated ankylotic stability which was confirmed by a mean Periotest value of -2.08. The radiographic analysis showed stable bone crest levels with a mean bone loss between the 1- and 5-year examination of 0.30 mm. However, 2 implants exhibited a bone loss of more than 1 mm between the 1- and 5-year examination. Therefore, the prognosis of these 2 implants seems questionable at the present time. It can be concluded that bone regenerated with the membrane technique reacts to implant placement like non-regenerated bone, since all 12 implants achieved successful tissue integration with functional ankylosis. Furthermore, this bone is also load-bearing, since all 12 implants maintained osseointegration over a 5-year period.