Alveolar Ridge Preservation Procedures Performed with A Freeze-Dried Bone Allograft: Histologic Outcomes in a Cohort Study: Part I.

Abstract

The primary aim of this study was to assess the histomorphometric outcomes of extraction sockets grafted with freeze-dried bone allograft (FDBA) and sealed with a collagen membrane after 3 months of healing in the ROI (region of interest) areas. The secondary aims were to analyze the biomaterial resorption rate, the bone to biomaterial contact and the area/perimeter of grafted particles compared with commercially available FDBA particles. Fifteen patients underwent tooth extractions and ridge preservation procedures performed with FDBA and a collagen membrane. Bone biopsies were harvested after 3 months at the time of implant insertion for histologic and histomorphometric analysis. Two areas of concern ROI1 and ROI2 with different histological features were identified within the biopsy samples; the ROI1, ROI2 and commercially available particles were analyzed and compared . The following parameters were analyzed: newly formed bone (NFB), marrow space (MS), residual graft particles (RGP), perimeter/area of FDBA particles and bone to biomaterial contact. The histomorphometric analysis showed 35.22 ± 10.79 % of newly formed bone, 52.55 ± 16.06 % of marrow spaces and 12.41 ± 7.87 % of residual graft. Moreover, the histologic data from the regions of interest (ROI) 1 and 2 showed that: a) the mean percentage of bone-to-biomaterial contact (BBC) was 64.61 ± 27.14 %; b) the Newly Formed Bone was significantly higher in ROI1 than in ROI2; c) the Marrow Space was significantly lower in ROI1 than ROI2 and d) the FDBA particles in ROI1 areas showed significant lower area and perimeter when compared to commercially available FDBA particles. This latter data lead to the hypothesis that FBA particles embedded in newly formed bone undergo a resorption/remodeling process.