Effects of the combination of bone morphogenetic protein-2 and nano-hydroxyapatite on the osseointegration of dental implants

ABSTRACT

Objectives@#This study aimed to investigate the in vitro osteoinductivity of the combination of bone morphogenetic protein-2 (BMP-2) and nanohydroxyapatite (nHAp) and the in vivo effects of implants coated with nHAp/BMP-2. @*Materials and Methods@#To evaluate the in vitro efficacy of nHAp/BMP-2 on bone formation, bone marrow-derived mesenchymal stem cells (BMMSCs) were seeded onto titanium disks coated with collagen (Col), ColHAp, or ColHAp/BMP-2. Protein levels were determined by a biochemical assay and reverse transcriptase-polymerase chain reaction. Stem cell differentiation was analyzed by flow cytometry. For in vivo studies with mice,Col, ColHAp, and ColHAp/BMP-2 were injected in subcutaneous pockets. Titanium implants or implants coated with ColHAp/BMP-2 were placed bilaterally on rabbit tibias and evaluated for 4 weeks. @*Results@#In the in vitro study, BM-MSCs on ColHAp/BMP-2 showed reduced levels of CD73, CD90, and CD105 and increased levels of glycos-aminoglycan, osteopontin, and alkaline phosphatase activity. After 4 weeks, the ColHAp/BMP-2 implant showed greater bone formation than the control (P=0.07), while no differences were observed in bone implant contact and removal torque. @*Conclusion@#These results suggest that a combination of BMP-2 and an nHAp carrier would activate osseointegration on dental implant surfaces.