Horizontal Ridge Augmentation using GBR with a Native Collagen Membrane and 1:1 Ratio of Particulated Xenograft and Autologous Bone: A 1-Year Prospective Clinical Study

Aim: To clinically and radiographically evaluate bone regeneration of severe horizontal bone defects.Materials and methods: This study was designed as a single cohort, prospective clinical trial. Partially or fully edentulous patients, having less then 4 mm of residual horizontal bone width were selected and consecutively treated with resorbable collagen membranes and a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, 7 months before implant placement. Tapered body implants were inserted and loaded 3 to 6 months later with a screw retained crown or bridge. Outcomes were: implant survival rate, any biological and prosthetic complications, horizontal alveolar bone dimensional changes measured on cone beam computed tomography (CBCT) taken at baseline and at implant insertion, peri-implant marginal bone level changes measured on periapical radiographs, plaque index (PI), and bleeding on probing index (BoP).Results: Eighteen consecutive patients (11 females, 7 males) with a mean age of 56.8 years (range 24-78) and 22 treated sites received 55 regular platform implants. No patient dropped-out and no implants failed during the entire follow-up, resulting in a cumulative implant survival rate of 100%. No prosthetic or biological complications were recorded. Supraimposition of pre- and 7-month post-operative CBCT scans revealed an average horizontal bone gain of 5.03 ± 2.15 mm (95% CI: 4.13-5.92 mm). One year after final prosthesis delivery, mean marginal bone loss was 1.03 ± 0.21 mm (95% CI 0.83-1.17 mm). PI was 11.1% and BoP was 5.6%.Conclusion: Within the limitation of the present study, high implant survival rate and high average bone augmentation seem to validate the use of collagen resorbable membranes with a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, for the reconstruction of severe horizontal ridge defects.