## 4 Discussion  
In the present systematic review and meta-analysis, four articles were included, comprising a total of 55 patients who underwent ARP with autogenous mineralized dentin, followed by dental implant placement after a healing period of at least 4 months. A variety of methodologies were employed in order to assess the characteristics of AMD. All studies followed the previously outlined protocol for the preparation of dentin [36]. However, [PERSON] et al. [47], [PERSON] et al. [23], and [PERSON] et al. [46] employed the Smartentin Grinder(tm) Device (KometaBio, Fort Lee, NJ, USA), while [PERSON] et al. [48] employed the Gold Bone Mill (MCT Bio, Seoul, Republic of Korea). In the studies by [PERSON] et al. [48], [PERSON] et al. [23], and [PERSON] et al. [46], only mineralized dentin and a resorbable collagen membrane were utilized. In contrast, [PERSON] et al. 's [40] study incorporated mineralized dentin, liquid fibrinogen, and leukocyte- and platelet-rich fibrin (L-PRF) membrane. In the study by [PERSON] et al. [49], the combination of liquid fibrinogen with an L-PRF membrane demonstrated the continuous release of growth factors for up to 14 days after applying these biomaterials, highlighting their potential as bioactive agents. Concurrently, this combination exhibited strong bactericidal activity, indicating its potential efficacy in combating postoperative infections [50]. The research by [PERSON] et al. [51] examined the effects of a platelet-rich fibrin (PRF) membrane. It concluded that it releases growth factors gradually for at least one week, thus stimulating the healing environment during a significant remodeling period. Furthermore, this study evaluated the effects of leukocytes, which have been demonstrated to produce substantial amounts of Transforming Growth Factor Beta 1 (TGF-81) and vascular endothelial growth factor (VEGF) and can, therefore, be considered an active source of growth factors [51]. The VEGF produced by leukocytes plays a role in the healing process and promotes angiogenesis [51]. These characteristics may help explain why the study by [PERSON] et al. [47] yielded the best results, demonstrating the highest percentage of newly formed bone and the lowest percentage of residual dentin. The studies present similar protocols; however, notable differences exist among them. These variations in study design, methodologies, and procedures can introduce substantial heterogeneity, complicating the interpretation of results and limiting the ability to draw robust conclusions. Differences in patient selection criteria may result in variations in initial characteristics, such as age and sex distribution, which were consequently selected as covariates for the meta-regressions conducted. Similarly, discrepancies in the preparation of the mineralized dentin graft may lead to different effects, complicating direct comparisons of results between studies. The timing of follow-up is another crucial factor. The study by [PERSON] et al. [47], which evaluated patients at 4, 5, and 6 months post-extraction, may have observed varying effects due to this difference, adding further complexity to comparisons among studies. In the meta-analysis related to the mean percentage of newly formed bone, it was concluded that there is a positive effect of mineralized dentin (Cochran's Q test, \(p\) = 0.004) and that the clinical implications of these results are significant. The ability of AMD  
Figure 13: Leave-one-out meta-analysis for residual graft (%). The dashed red line represents the overall meta-analytic mean [23; 46; 47; 48]. to promote newly formed bone without eliciting an immunologic response suggests its potential as a biomaterial for alveolar ridge preservation [21]. The age analysis revealed a significant relationship between the mean age of patients and the amount of newly formed bone (Wald test, \(p\) = 0.003).