Periodontal Biotype Influence on the Volume Maintenance of Onlay Grafts

Abstract

Autogenous osseous transplants have advantages, including the maintenance of bone density and high concentrations of growth factors. Little is known about the potential long-term influence of periodontal biotype on the volume maintenance of block grafts. Forty patients who received autogenous block transplants prior to implant placement were included in the study. Digital photographs and periapical radiographs were taken after restoration. Clinical parameters, including bleeding on probing, mobility, suppuration, mucosal recession, and buccal tissue transparency, were recorded at yearly intervals. A computerized tomography (CT) scan was taken at an average of 42 months (n = 20) postaugmentation. The clinical examination revealed no implant transparency, mucosal recession, mobility, bleeding on probing, or suppuration (n = 40) at 48 months. CT scans showed varying thicknesses (0.5 to 4 mm) of buccal cortical bone around the implants. The increased width at the recipient site postgraft was 7.6 mm, maintaining, on average, 98% of the augmented width. The buccal osseous thickness at the implant sites averaged 2.0 +/- 0.8 mm compared to 0.7 +/- 0.5 mm for the adjacent teeth (95% confidence interval: 0.85 to 1.65 mm; P <0.0001). Even when adjacent teeth had a thin biotype, the transplanted sites maintained statistically significant thicker buccal cortical plate at all sites (P <0.0001). Grafted site phenotype did not seem to be influenced by the adjacent teeth biotype. Autogenous osseous transplants can predictably reconstruct function and esthetics and seemed to maintain stable bone volume around implants at an average of 3.5 years.