Osteoinduction of recombinant human bone morphogenetic protein-2 coated biphasic calcium phosphate in rabbit maxillary sinus augmentation: a histometric analysis

Abstract

Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been used in sinus augmentation but suitable carriers that retain certain amounts of BMPs and space providing properties were required. Biphasic calcium phosphate (BCP) have been suitable candidates for a rhBMP-2 delivery system because of their osteoconductive properties, space-providing properties, biocompatibility and structurally similarity to human bone tissue. The objective of this study was to evaluate the osteoinductive potential of low concentration of rhBMP-2 coated BCP (LCB) in a rabbit maxillary sinus model. Bilateral, circular windows were prepared at the sinus area of normal skulls in eight New Zealand white rabbits using 6-mm diameter trephine bur. The trephined bony disk was carefully removed and the membrane was elevated and one side received LCB while the other side received BCP with saline. The histologic and histometric analysis was performed after 2 weeks. Clinical healing was generally uneventful. The total amount of new bone formation revealed no significant difference between groups, but when divided into 3 sectional areas (window / center / membrane) there were some difference. In the rhBMP-2 group, newly formed bone was greater at the membrane areas, however in the control group, window areas represented greater new bone formation. Within the limitation of this study, LCB was capable of promoting new bone formation in the membrane area relatively and induced chemotaxis in the early healing stage.