Analysis of Organic Components and Osteoinductivity in Autogenous Tooth Bone Graft Material

Purpose: Extensive research is actively ongoing for development of an ideal bone substitute that meets the gold standard. Tooth was selected as a donor site for evaluation of potentials in bone substitutes based on its similar chemical compositions to alveolar bone. Previous studies have evaluated inorganic components of autogenous tooth bone graft material (AutoBT) and osteoconductivity. In continuation from the previous studies, the current study was conducted for analysis of organic components and evaluation of osteoinductivity of AutoBT. Methods: Forty-six extracted teeth were collected from actual patients (Korea Tooth Bank, R&D Institute). Extracted teeth were processed into AutoBT and implanted in dorsal subcutaneous muscular tissues of 15 athymic mice. Biopsy samples were harvested at two, five, and eight weeks. The Bradford assay, sodium dodecyl sulphate polyacrylamide gradient gel, and western blotting were performed for investigation of organic contents of AutoBT. Results: Histology analyses showed signs of new bone formation as early as two weeks. Results of the Bradford assay indicated the existence of noncollagenous proteins (NCP). 0.29% (2.89 mg/g) of proteins were extracted by weight in the root portion of AutoBT; 0.02% (0.029 mg/g) and 1.79% (17.93 mg/g) of proteins were measured by weight in crown and block-form of AutoBT, respectively. However, recombinant human bone morphogenetic protein-2 was not observed in AutoBT. Conclusion: Within the limitation of the current study, AutoBT induced new bone formation by NCP embedded in dentin.