Human acid-insoluble dentin with BMP-2 accelerates bone induction in subcutaneous and intramuscular tissues

Abstract

Dentin matrix is well known as the most insoluble collagen in human body. We already confirmed the osteoinductive property by granules of human demineralized dentin matrix (DDM) histologically. Human DDM granules and human demineralized root-dentin (DRD) mass were prepared from adult vital teeth. The hard tissue induction by DDM alone or DRD alone was estimated at 4 weeks after implantation. The DDM alone induced bone and cartilage independently. In addition, the bioassay by recombinant human BMP-2 (5.0 µg)/DDM or BMP-2 (5.0 µg)/DRD was estimated in mouse subcutaneous or intramuscular tissues, respectively. Histological examination showed that the BMP-2/DDM induced bone and marrow, and the DDM granules were partially absorbed by new bone. The morphometric analysis demonstrated that the BMP-2/DDM showed 36.3% in the volume of bone and marrow, while the DDM alone showed 1.3% at 4 weeks. Moreover, the BMP-2/DRD also induced active bone formation on the root surface and in the pulp cavity. These results indicate that BMP-2 significantly accelerated bone formation in decalcified dentin implants. Human recycled DDM and DRD might be effective materials as osteoinductive collagenous carriers of BMP-2 for bone engineering.