Histological Evaluation of Healing Following Ridge Preservation Using a Combined Cortical/Cancellous Mineralized Freeze-Dried Bone Allograf

Alveolar ridge preservation is performed with a primary goal of reducing the dimensional loss of alveolar bone upon tooth extraction. Mineralized freeze-dried bone allografts are commonly used in this modality and have been documented in the literature to be successful in diminishing the dimensional loss of alveolar bone and permitting the formation of new bone growth through their osteoconductive properties. Products exist which provide combinations of cortical and cancellous particles within the mineralized freeze-dried allograft. To date, there is no research to guide the clinician as to whether a cortico-cancellous allograft is superior to either a pure cortical or pure cancellous allograft. Therefore, the primary objective of this study is to dimensionally and histologically evaluate healing in non-molar sites using a combined 50/50% cortical-cancellous freeze-dried bone allograft compared with a 100% cortical FDBA.;Forty-four patients were randomized into two equal groups receiving ridge preservation with either a 100% mineralized cortical FDBA or a combined 50/50% mineralized cortico-cancellous allograft. The non-molar study sites underwent an 18-20 week healing period, at which time a core biopsy was harvested and a dental implant was placed. Alveolar ridge dimensions were measured immediately following tooth extraction and again at the time of core biopsy and implant placement. These measurements included changes in ridge width and in buccal and lingual ridge height. Histomorphometric analysis of the core biopsies allowed determination of tissue percentages of: vital bone, residual graft particles, and connective tissue/other components.;Regarding the primary objective of histologic differences between groups, there were no significant differences with regard to percentage of vital bone, residual graft, or connective tissue/other components. Dimensionally, the combination 50/50% cortico-cancellous allograft had a significant loss in ridge width (p=0.002) from extraction to implant placement; all other dimensional measurements were not significant for either group.;This study provides evidence that the use of a combination 50/50% cortico-cancellous freeze-dried bone allograft is not superior to use of a 100% cortical freeze-dried bone allograft in the application of alveolar ridge preservation in humans.