Maxillary ridge augmentation using fresh-frozen bone allografts: Histological evaluation

Objectives: Increasing popularity of dental implant surgery has created heavy demand for dentoalveolar reconstruction using grafting products. Bone allograft has become an alternative to autogenous bone due to its decreased operative trauma and almost unlimited supply of reconstructive material. The aim of the present study was to histologically evaluate the viability of fresh-frozen bone graft (test group) used in maxillary ridge augmentation, comparing it to autogenous bone (control group) using the Picrosirius-polarization method. Methods: Eighteen patients who had atrophic maxillary ridge necessitating bone block grafts prior to implant placement, were submitted to maxillary reconstructions with human block grafts of tibia fresh-frozen chips. Nine months after the fresh-frozen allogeneic bone blocks were placed in the atrophic maxillary ridges, during the re-entry procedures, bone cores were removed with a trephine bur from test and control group. Routine histologic processing using HE and Picrosirius staining was performed. Mature and immature collagen area and density analysis for both groups under polarized light were taken and Student's t-test for paired samples (p>0.05) were applied. Results: No statistically significant differences were observed in mature and immature collagen area and density percentage for test and control groups. Histologically similar bone formation patterns were observed between both groups. Conclusions: We concluded that fresh-frozen allogeneic bone is viable for maxillary ridge augmentation, showing a similar collagen pattern to that of autogenous bone. (Grant: CNPq - 475511/2008-5)