Bone Level Variation After Vertical Ridge Augmentation: Resorbable Barriers Versus Titanium-Reinforced Barriers. A 6-Year Double-Blind Randomized Clinical Trial

Purpose: To compare the efficacy of two different techniques for vertical bone regeneration at implant placement with particulate autogenous bone at 6 years after loading by means of a double-blind, superiority, parallel-group randomized clinical trial. Materials and Methods: The study was conducted in a private center in Italy between April 2004 and December 2011. Patients in whom vertical bone augmentation was indicated in combination with the placement of single or multiple implants were eligible for inclusion in this trial. Patients were randomized to receive either resorbable collagen barriers supported by an osteosynthesis plate (test group) or nonresorbable titanium-reinforced expanded polytetrafluoroethylene barriers (control group). The outcome variables-radiographic bone variation at implant sites, implant failures, and complications- were evaluated 6 years after loading. Randomization was done by computer, with allocation concealed by opaque sequentially numbered sealed envelopes. The patients and the radiographic examiner were blinded to group assignment. Results: Twenty-two patients were randomized: 11 to the resorbable barrier group and 11 to the nonresorbable (control) group. One control group patient dropped out. The mean bone level 6 years after surgery was 1.33 mm for the resorbable group and 1.00 mm for the nonresorbable group. The adjusted difference in bone changes between groups was 0.15 mm (95% confidence interval, -0.39 to 0.69, P = .5713). No implant failures or complications occurred after loading. Conclusion: No differences were observed in this comparison of resorbable and nonresorbable barriers with simultaneous implant placement for vertical ridge augmentation. Keywords: alveolar ridge augmentation, bone grafting, dental implants, guided bone regeneration, randomized clinical trial