Purpose: Bovine-derived bone xenograft and mineralized cancellous bone allograft have been successfully used as bone substitutes in dental surgery, but few clinical studies in humans have been reported. The objective of this study was to compare the osteoconductive effects of deproteinized bovine bone mineral (DBBM), irradiated cancellous allograft (ICA), and solvent-dehydrated allograft (SDA) when used to preserve extraction sockets. Materials and Methods: Twenty patients received bone grafting in extraction sockets with DBBM (n = 7), ICA (n = 8), or SDA (n = 5). Core biopsies were taken from each graft site 4 to 6 months after grafting and were evaluated histomorphometrically. One-way analysis of variance was used to compare each variable. P values less than .05 were considered significant. Results: DBBM induced more new bone deposition in the periphery of the native bone particles than ICA or SDA, whereas ICA and SDA were more frequently surrounded by fibrous tissue than DBBM. In addition, DBBM retained more residual graft bony particles than ICA or SDA. Conclusions: Based on these findings, the DBBM showed more of an osteoconductive effect than ICA or SDA, producing a more rigid bony structure. It is therefore suggested that DBBM may be more favorable for the preservation of extraction sockets than allogeneic graft materials. Keywords: bovine xenograft, histomorphometry, mineralized cancellous bone allograft, socket preservation