Clinical and radiographic evaluation, following delivery of fixed reconstructions, at GBR treated titanium fixtures

Conditions following incorporation of fixed reconstructions, at endosseous titanium implants augmented at local bony dehiscence and fenestration defects using a bioabsorbable Resolut membrane were studied in 7 patients. Fixture stability, radiographic marginal bone levels and peri-implant soft tissue status were evaluated at 21 membrane treated and 17 control fixtures (installed in regions of adequate bone volume), following a 2-year period of functional loading. Prosthetic reconstructions were removed and clinical examination and Periotest values revealed that all fixtures were stable. All peri-implant soft tissues were clinically healthy. The mean probing depths at buccal sites for fixtures with original dehiscence (n = 10) and fenestration (n = 11) defects were 1.6 +/- 0.7 mm and 1.2 +/- 0.4 mm respectively. The control fixture group had a mean buccal probing depth of 1.4 +/- 0.6 mm. At abutment connection radiograph membrane treated fixtures had significantly lower marginal bone levels than control fixtures, indicating that optimal bone regeneration was not achieved at all defects. Mean radiographic bone loss 23-27 months following delivery of fixed reconstructions for original dehiscence and fenestration defect fixtures was 0.7 +/- 0.8 mm and 0.8 +/- 0.6 mm respectively at mesial surfaces, and 0.8 +/- 0.7 mm and 0.6 +/- 0.5 mm at distal surfaces. In the control fixture group a mean loss of 0.7 +/- 0.5 mm at mesial surfaces and 0.5 +/- 0.4 mm at distal surfaces was found. Results showed no significant difference in the rate of bone loss following functional loading between membrane treated and control fixtures.