Porcine Cortical Bone Lamina as a Predictable Technique for Guided Bone Regeneration: Histomorphometric and Radiographic Evaluation

Abstract

The stability of bone regenerated through Guided Bone Regeneration (GBR) around implants is crucial for long-term success. In this case series, changes in marginal bone levels (MBL) around implants placed in a regenerated bone using heterologous cortical lamina technique were radiographically measured. In addition, bone samples were obtained and submitted to histological and histomorphometric analysis. Thirty implants were placed in regenerated bone sites 8 months after the regenerative surgery; in the same surgical stage, a hard tissue biopsy was taken using a trephine bur and submitted to histologic and histomorphometric analysis. Changes in the marginal bone level, mesial and distal to the implant shoulder, were measured between prosthetic loading and the last follow-up, 2 years later. No implants were lost, and all could be deemed successful at the last follow-up. Only a minimal mean variation in the position of the marginal bone level was observed, both at the mesial (0.11 ± 0.49 mm) and at the distal level (0.03 ± 0.19 mm). The bone lamina had been resorbed after 8 months, and new bone had developed in close connection to the biomaterial. The average percentage of newly formed bone was 28%, while only 10% of the samples were composed of residual biomaterial; bone marrow and connective tissue composed the remaining part of the samples. This regeneration technique allowed, thanks to the rigidity of the lamina, the regeneration of new bone, which is stable after the prosthetic load. Further studies are needed to compare this procedure with those adopting non-resorbable, titanium-supported membranes.