Bone Regeneration by Demineralized Dentin Matrix in Skull Defects of Rats

Alveolar bone defects may result in functional and morphological abnormalities. In such cases, bone can be regenerated by grafting fresh autogenous bone into the defect. Subsequently, we focused on the dentin of third molars, which are usually discarded after extraction, or teeth removed faor orthodontic therapy. As in bone, type I collagen is the main component of the organic matrix in dentin. Also, it has been proven that the organic matrix of dentin contains osteoinductive bone morphogenetic protein (BMP). It would be safe to perform grafting with the dentin of extracted teeth used as an autogenous bone substitute. Therefore, the objective of the present study was to reuse extracted teeth as a bone substitute material. Demineralized dentin matrix (DDM), an organic material derived from the dentine of bovine teeth, was grafted in rat skull defects to determine its bone regeneration ability and the possibility of its use as a bone substitute. In the present study, new bone formed from the defect margin in the control group, but in the graft group, new bone formation occurred from individual DDM granules within the defect, and not just from the margin. At Week 8, defect repair was limited in the control group. In contrast, most of the defect was covered by osseous tissue in the graft group. In conclusion, DDM may be a useful bone substitute that serves as a scaffold for bone regeneration by inducing a high level of new bone formation soon after surgery.