Vertical guided bone regeneration with bioabsorbable barriers

Background: Guided bone regeneration (GBR) is a very useful surgical technique to increase limited alveolar bone for implant placement. The use of non-resorbable barriers is well established; however, bio-absorbable collagen membranes may simplify the surgical technique and make it more predictable. Methods: Vertical ridge augmentation was performed on I I patients at the time of implant placement. The part of the implant out of bone was covered with autogenous bone/graft, and a slow-resorption collagen membrane was placed on top. Gingival tissues were closed with horizontal mattress and interrupted sutures. Second-stage surgery was performed 4 to 6 months later and healing abutments were placed. The length of the implant out of bone was determined at stage I and stage 2 surgeries on a periapical x-ray I year after implant load. Histology was obtained from one of the cases at second-stage surgery. Results: Measurements revealed that the mean implant out of bone was 3.5 mm at stage I and 0.5 mm at stage 2. Mean bone gain was 3 mm, which represented 83% of the exposed implant at stage 1. One year after loading, implants showed a mean marginal bone loss of 1.4 mm. Minimal complications were detected, and only one case failed. Histology from one successful case showed new trabecular bone with large cellular marrow spaces in the regenerated area. Conclusion: Slow-resorption collagen membranes have the potential to promote vertical ridge augmentation when used with autogenous bone at the time of implant placement.