# Allogeneicic Demineralized Dentin Matrix Graft for Guided Bone Regeneration in Dental Implants
## 4 Discussion  
The purpose of this clinical pilot study was to analyze BMB resorption during 12 months after prosthetic loading of a dental implant with GBR using Allo-DDM. To the best of our knowledge, there are no prior data on BMB resorption after prosthetic loading of dental implants with Allo-DDM as GBR material. We hypothesized that Allo-DDM grafted around the dental implant would not be inferior to Auto-DDM in terms of BMB resorption after 12 months of functional loading. In this study, the initial resorption during the healing period before prosthetic loading was 0.73 and 0.72 mm with Auto- and Allo-DDM, respectively, which validates the previously reported clinical results (average 0.77 mm) of Auto-DDM applications for GBR at three to six months [25]. Another study comparing Auto-DDM with Bio-Oss collagen demonstrated vertical bone loss ranging between 0.97 and 1.13 mm, respectively, and showed that Auto-DDM was not inferior to Bio-Oss collagen [26]. A randomized, controlled, prospective, clinical pilot study using autogenous (mineralized)-tooth-graft in humans showed lower resorption values (average 0.28 mm) in the alveolar crest height at four months compared with \(\beta\)-tricalcium phosphate (\(\beta\)-TCP) (average 1.72 mm) and ungrafted sites (average 2.60 mm reduction) [27]. Thus, the evidence states that BMB resorption of Allo-DDM in GBR during the healing period was very similar to the Auto-DDM application, although most of the Auto-DDM studies were based on socket preservation without implant placement. Concerning Allo-DDM applications, [PERSON] et al. [21] conducted a randomized, controlled, prospective, clinical study on allogeneic mineralized dentin grafts in 15 patients for GBR without implant placement. They reported 0.31 mm of initial BMB resorption four months after the graft and showed the least amount of initial BMB resorption after GBR in comparison to freeze-dried bone allograft (FDBA) (0.87-mm of resorption) [21]. These studies indicate that initial BMB resorption with Allo-DDM during the healing stage before prosthetic loading showed similar results to those of other studies using Auto-DDM, which is not inferior to Bio-Oss collagen, FDBA, or \(\beta\)-TCP [28; 29; 30; 31]. Both functional BMB resorption of 0.69 and 0.48 mm in Auto-DDM and Allo-DDM, respectively, in this study complied with the long-term success criterion, which is defined as BMB loss \(<\) 1.5 mm within the first year after prosthetic loading [32]. With particulate autogenous bone grafts, the BMB loss around dental implants was 0.74 mm at three months, with up to 1.67 mm of resorption at  
Figure 4: Histological findings of autogenous demineralized dentin matrix (Auto-DDM) and allogeneic demineralized dentin matrix (Allo-DDM) grafts at four months of guided bone regeneration. (Left; Allo-DDM, Right; Auto-DDM). Woven bone formation, maturation with primary and secondary osteons, and remodeling with developing blood vessels (red arrowhead). Newly formed osteoid surrounded the DDM particle (asterisk) closely without gaps (black arrowhead). There was no inflammatory cell infiltration or impingement of the connective tissue into DDM particles. 12 months [33]. In a prospective clinical study of Auto-DDM versus Bio-Oss granules in GBR for immediate implantation in periodontal post-extraction sites, Auto-DDM (1.9 mm) and Bio-Oss (2.0 mm) showed similar results for BMB resorption values at six months postoperatively [11]. In a five-year follow-up of five patients who received Auto-DDM grafts for GBR, only one patient showed BMB resorption of 1 mm [9]. Even when the implant was placed without a bone graft, the BMB resorption was approximately 1 mm during the first year [34]. The authors noted that the bone-retaining group at the 1-year time point had thicker buccal bone walls at baseline compared with the bone-loss group. The initial buccal bone contour (thickness) was significantly associated with bone retention or loss at 1 year [34].