Bone augmentation at fenestrated implants by an osteopromotive membrane technique. A controlled clinical study

Lack of bone in localized areas of the jaws frequently poses a problem when placing oral implants. In this clinical study, we have tested an osteopromotive membrane technique for its ability to create bone over buccal fenestrations after fixture installation in the maxilla. 7 patients were selected by the use of CT-scan. Criteria for patient selection were that the alveolar crest should have a vertical height >13 mm and a facial-palatal concavity, where exposure at the central portion of the fixture could be anticipated. One fenestration, randomly chosen, in each patient was covered with an e-PTFE (expanded polytetrafluoroethylene) (Gore-Tex GTAM) membrane. Contralateral fenestrations served as controls (without the placement of a membrane). The amount of newly formed bone was calculated by photometric assessments. The results showed that the fixture fenestrations, treated with the membrane technique, demonstrated a significantly (p<0.005) higher amount of new bone formation compared to the controls, where little or no improvement had taken place at the fenestrations. The study conclusively shows that the membrane technique is a reconstructive technique, able to create new bone at localized bone fenestrations at titanium fixtures. Additionally, the study also demonstrates that the periosteum alone, in adult humans, is not capable of generating new bone at exposed titanium implants.