Effect Of Coral Artificial Bone Composite Of Human Recombinant Bone Morphogenetic Protein-2 And Coral Artificial Bone On Orthodontic Tooth Movement

Purpose This study was conducted to evaluate the effect of coral artificial bone composite of rhBMP-2 (rhBMP-2/CAB) and coral artificial bone(CAB) implanted in alveolar bone on orthodontic tooth movement. Methods 12 adult dogs served as the experimental animals. Immediately after extraction of the upper second and third incisors, the alveolar septum between extracted sockets was resected bilaterally. RhBMP-2/CAB and CAB were respectively implanted into each extracted site. Experimental tooth movement was initiated 2 weeks after the grafting and continued for 2 to 10 weeks. Sectional archwires with opencoil springs activated to deliver 1 50g of force were used for distal movement of the upper first incisors into the extracted sites. The animals were sacrificed at 4 th, 8th and 12th week respectively after implantation. The distance of tooth movement was measured at 0, 4, 8 and 12 weeks. The interface between root and periodontal tissue was assessed by histology and the bone repairing ability of the two grafts was analyzed with X-ray, radioisotope scintigraphy using 99Tcm-MDP(technetiurn-99m-methylene diphosphonate), histology and image analysis system. Results The amount of tooth movement ranged from 1.00 to 2.99 mm on the side of rhBMP-2/CAB and from 0.99 to 3.11 mm on the side of CAB. There was no significant difference between the two groups(p>0.05). The radioactive mean counts of regions of interest (ROI) in rhBMP-2/CAB site were significantly higher than that of CAB site at 4 and 8 weeks respectively after implantation (pO.05). The ratio of new bone formation of rhBMP-2/CAB was significantly higher than that of CAB at different period(p