# The Use of Autogenous Teeth for Alveolar Ridge Preservation: A Literature Review
## 3 Autogenous Teeth as a Bone Graft Material
### Dentin Processing  
As aforementioned, autogenous teeth can be used as bone graft material with osteeoconductive and osteoinductive potential [9, 12]. However, several concerns have been addressed regarding the need for any dentin processing prior to bone grafting for the purpose of clinical optimization. Some examples are the extraction of non-collagenous proteins [42], elimination of the organic matrix [14] and finally, one of the most commonly used, dentin preparation by demineralization [12]. The hypothesis of demineralization is that through this procedure, the organic substances (type 1 collagen fibrils, non-collagenous proteins and growth factors) will be more exposed, decreasing the graft crystallinity and increasing its porosity and surface area [16, 35, 43]. This process releases growth factors and non-collagenous proteins, which in turn, results in an enhanced osteoinductive activity [14]. Although protocols vary from study to study, a general protocol includes tooth extraction, removal of soft tissue, carious lesions and filling materials of any nature [17, 44, 45, 46], sectioning into blocks or particles and finally choosing the degree of demineralization [47]. Among the demineralization agent are ethylenediaminetetraacetic acid (EDTA), phosphoric acid, chloridic acid, nitric acid, hydrogen oxide, ethyl ether and ethyl alcohol [14]. Hence, dentin materials were categorized into 3 categories: demineralized dentin matrix (DDM), partially demineralized dentin matrix (PDDM) and undemineralized dentin (UDD) [12]. While some investigators have reported success when using DDM (or PDDM) [17, 37, 39, 40, 44, 48, 49, 50] others prefer using in its undemineralized form [38, 51, 52, 53, 54, 55, 56, 57]. Mineralized dentin particles offer a mechanical stability, creating a solid site for implant placement [38, 52]. With the use of a mineralized graft, although the osteoinductive properties of dentin may be delayed, the low crystallinity of dentin hydroxyapatite allows the progressive bone remodeling [15, 30]. Due to a lack of uniformity and standardization in the literature, it is difficult to determine with certainty which form of graft is advantageous for which clinical indication. Regarding ARP procedures, several authors have reported success when using DDM, PDDM and UDD, indicating that each form can be a viable option [38, 40, 41]. Nonetheless, some authors suggest an approach patient-based. DDM and PDDM can be indicated when the socket walls have already been resorbed or destroyed due to pathological causes [58]. The exposure of growth factors and non-collagenous proteins, as previously stated, will allow an earlier regeneration [14, 38]. The UDM on the other hand, thanks to the mechanical stability inherent to the graft, may allow an earlier placement of dental implants [38]. As previously stated, the amount of biomaterial that the clinician can gather is dependent on the extension of carious lesions and filling materials [17, 44, 45, 46], nonetheless, one possible approach that can overcome this limitation is the extraction of impacted third molars, when it is required a larger amount of biomaterial [51, 59]. In order to obtain a demineralized graft, the Korea Tooth Bank, established in Seoul, was one of the first to be available for clinicians [60]. However, due to this time-consuming option, several devices appeared on the market for this purpose. The VacuaSonic(r) (Cosmobiomedicare, Seoul, Korea) produces a demineralized graft. This system comes with a powder reagent (DecalSi(r) DM Powder reagent) and a block reagent (DecalSi(r) DM Block reagent), giving the clinician a choice, on which form of graft he prefers. According to the manufacturer, the process takes 30 min for powder graft and 2 h for block graft [50]. Another system that can be used is the Smart Dentin Grinder(tm) (Kometa Bio ltd., Holon, Israel) which is a device that grinds the tooth to particles of 250-1200 \(\upmu\)m, according to the manufacturer.