The healing capacity and osteogenesis pattern of Demineralized Dentin Matrix (DDM)-Fibrin Glue (FG) compound

Abstract

Abstract Demineralized dentin matrix (DDM) is an osteoconductive and osteoinductive material, which was successfully performed in sinus floor augmentation and alveolar ridge augmentation in clinical application. It releases bone morphogenetic protein (BMP) and other growth factors which make DDM a suitable grafting material. However, the granular particle of DDM makes it difficult to anchor into the bone defect area. The aim of this study was to investigate biological effects as well as an osteoinductivity of the combination of DDM and Fibrin Glue (FG) at an optimal ratio on bone healing from critical bone defect in an animal model. Mouse osteoblastic cell line (MC3T3-E1) was co-cultured with various ratios of DDM and FG to examine their effects on osteoblast proliferation and differentiation indicated by alkaline phosphatase (ALP) activity, osteocalcin (OC) production and mineralized nodules formation. The optimal ratio was then chosen to further study with rabbit calvarial defective model which they were implanted with DDM or DDM-FG1 (1:0.1) and DDM-FG2 (1:0.5) compounds (w/v) or blank for 2, 4, 8 and 12weeks for investigating soft tissue and new bone regeneration. Micro-CT and histology analysis were used to evaluate the total grafting properties according to the different healing periods. The result from in vitro studies demonstrated that the ratio of 1:0.1 induced more ALP activity, mineralized nodules at the same time, 1: 0.5 (DDM-FG combined) induced more Osteocalcin (OC) at given days. In animal model, the 3D new bone volume in all DDM-FG treatment were significantly greater than blank group at 2, 4, 8 and 12 weeks. Furthermore, the new bone volume was greater in DDM-FG2 when compared to other groups at early week of the healing period. In histological analysis, numbers of osteoblasts were formed as a cluster adjacent to the DDM particles where we could observe a newly formed bone in all groups suggesting an osteoinductive property of DDM. Moreover, the greater new collagen synthesis observed at 4 weeks suggested that the early bone healing was induced in a group treated with DDM-FG2. This study demonstrates that at optimal ratio of DDM-FG compound enhances the osteogenic activities and bone regeneration.