Effect of GBR and fixture installation on gingiva and bone levels at adjacent teeth.

Guided bone regeneration (GBR) is frequently used in oral implantology. It is unclear to what extent GBR affects the periodontium of adjacent teeth. Therefore, the present study quantifies changes in the proximal gingiva and bone levels at these teeth in 30 patients. Staged surgery involved a standard GBR treatment, randomly using resorbable membranes with a bone substitute or non-resorbable membranes with or without a bone substitute, followed by fixture installation at 6 months and abutment connection a further 6 months later. The data were sampled at each surgery and analysed using MANOVA. Twelve months after GBR, there was on average a small but statistically significant amount of proximal gingival recession (0.75 mm) and bone resorption (0.34 mm) observed, of which 50% was the result of GBR surgery. No significant differences were found between the different GBR treatment modalities. It is concluded that GBR treatment may have a small negative effect on the levels of the free gingival margin and alveolar bone at adjacent teeth, which is in most patients not clinically relevant.