Anterior tooth replacement with implants in patients with a narrow alveolar ridge form. A clinical study using guided tissue regeneration.

Clinical and radiographic examination was used to select patients with a suspected need of guided tissue regeneration (GTR). Fifteen patients with 20 fixtures were included in the study. Nine (45%) of the fixtures were completely covered with bone at fixture surgery and no GTR was required in these cases. On the remaining 11 fixtures, one or more sites were exposed and thus an expanded polytetrafluoroethylene membrane was used. The regenerative results were assessed using 2 methods, a) calculation of exposed threads in the mouth and on projected colour slides, b) photometric evaluation of exposed area. In total, the membrane group showed a bone gain of 81% when threads were calculated. Almost complete agreement in percentage of bone gain was observed between buccal (80.7%) and lingual (82.6%) sites. Photometric evaluation for the buccal sites showed a bone gain of 74%. Complete bone regeneration (100%) was achieved when healing was free from complications and also under an exposed membrane when infection was absent. The results indicate that the membrane technique is highly successful for treatment of exposed implants when healing is free from complications. It also shows that clinical and radiographic examination is not precise enough to differentiate between those patients planned for routine fixture surgery and those with a supplementary need for GTR. Thus access to GTR technique is important when treatment is planned for borderline cases.