## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Ridge Preservation Sites** & **Number** & **Group A** & **Group B** & **Group C** \\ \hline Grafted area (\%) & \(n=6\) & 13.20 \(\pm\) 9.79 & 10.72 \(\pm\) 9.83 & 11.02 \(\pm\) 12.72 \\ New bone area (\%) & \(n=6\) & 22.00 \(\pm\) 11.01 & 32.88 \(\pm\) 14.48 & 39.09 \(\pm\) 15.30 \\ Soft tissue area (\%) & \(n=6\) & 64.80 \(\pm\) 10.11 & 56.40 \(\pm\) 8.58 & 49.88 \(\pm\) 11.14 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Histomorphometric analysis of 3 different groups at 4 month reentry. (10.60 \(\pm\) 1.90 mm), with no significant differences between these three groups. Similarly, at the level of 3 mm (RW-3), the level of ridge alteration was not statistically different among the groups. However, at the level of 5 mm (RW-5), the Bio-Oss(r) Collagen group exhibited significantly greater loss in width (0.50 \(\pm\) 0.19 mm), compared to Group B (0.20 \(\pm\) 0.15 mm) treated with DDM. Nevertheless, the apical portion of the alveolar socket (RW-5) is less important and dynamic, as the majority of the apical portion of the buccal bone plate is lamellar bone [41]. The marginal portion of the crest (RW-1 and RW-3 mm) is more critical in the bone remodeling cascade due to the bundle bone. In accordance with these results, the loss of ridge width can be reduced by ridge preservation with DDM, considering it equivalent to DBBC. Previous studies have also documented that DDM and deproteinized bovine bone can act as favorable biomaterials to preclude atrophic ridge alteration after tooth extraction [14]. A range of biomaterials used for ridge preservation have been documented and categorized in the literature [42]. Among them, the emerging autogenous dentin materials were successfully used for various clinical situations including guided bone regeneration (GBR), sinus grafts, and ridge preservation [20; 21]. Many studies have indicated that manipulated dentin materials can act as osteoconductive or even osteoinductive substitutes for common graft biomaterials [31]. In addition, this novel DDM material has been applied as an rhBMP-2 carrier as well as a bone substitute. The bone healing process proceeds with the formation of blood clots, migration and proliferation of mesenchymal stem cells, granulation tissue formation, angiogenesis, proliferation of fibroblasts, and collagen synthesis. Thus, mesenchymal stem cells are essential for the bone healing process, and mesenchymal stem cell markers such as CXCR4, CD106, CD146, OCT-4, NANOG, CD34, CD146 and CD105 are upregulated at bone healing sites [43]. rhBMP-2 has been utilized to stimulate osteoblastic proliferation from mesenchymal stem cells and accelerates bone regeneration [24]. Although numerous bone morphogenetic protein (BMP) carriers have been tested, such as collagen, demineralized bovine bone, and hydroxyapatite, these carriers have several shortcomings, such as rapid resorption, lack of long-term maintenance of volume, and incompetent release of BMP. Processed demineralized dentin is already recognized as a rhBMP-2 carrier, since it facilitates induction of new bone formation and helps to release BMP slowly [44]. A recent animal study by [PERSON] et al. demonstrated that DDM dissolves rhBMP-2 more gradually and steadily than other tricalcium phosphates (TCP) and bovine bone, establishing that particulated DDM is the most effective BMP carrier [31]. Other studies have reported that adding rhBMP-2 to DDM ensures the formation of new bone and cartilage, and DDM is absorbed and replaced by vital new bone tissue approaching almost 80% of the total volume, as indicated by histomorphometric assessment [23; 45]. The current study was undertaken to evaluate, using a histomorphometric assessment, whether the addition of rhBMP-2 to DDM leads to superior bone regeneration in comparison with DDM alone or conventional DBBC.