The effects of RhKMP- 2 on the extracted bone healing after zolendronic acid treatment in ovarectomized rats

The aim of this study is to determine the histologic findings of rhBMP-2 on extracted bone healing after zolendronic acid (ZOL) treatment in ovarectomized rats. This study was performed on 42 female, 12 weeks old, 225 gr Spraque- Dawley rats. All rats were untreated for the first 4 weeks after surgery to allow for the development of osteopenia and all rats were divided into 3 groups. In control group, 14 rats were injected 7,5 ?g/kg ZOL a week and 1mg/kg deksamethazone (DX) everyday for 2 weeks. In second group (group A), 14 rats were injected 7,5 ?g/kg ZOL a week and 1mg/kg deksamethazone (DX) everyday for 2 weeks. In third group (group B), 14 rats were injected 7,5 ?g/kg ZOL a week and 1mg/kg deksamethazone (DX) everyday for 3 weeks. Each groups were divided into two groups according to extraction of molar teeth in maxilla or mandible. 2 weeks after first injection for control and group A and 3 weeks after for group B. Collagen carrier with rhBMP-2 implanted into the extraction socket in group A and B. All animals were sacrificed 4 weeks following tooth extractions. In all groups, weights of the rats on ovarectomy, tooth extraction, first injection and sacrification and histological findings such as inflamation, new bone formation and necrotic bone presence were recorded. There was statistically significant difference between the body weights of rats in all groups. A significant decrease of body weights was found in group B then control (p=0.005; p<0.01) and group A (p=0.001; p<0.01) between first injection and tooth extraction. There was no statistically difference between inflamation, new bone formation and necrotic bone in maxilla and mandible (p>0.05). New bone formation was observed in 5 (%71,4) group A and 2 (%28,6) group B (p=0,017). In all groups there was a statistically significant difference in mandible for new bone formation (p<0.05). There were better new bone formation in group A then control group (p=0,021; p<0.05). Necrotic bone was observed 1 (%14,3) in control and group A, 5 (%71,4) in group B (p=0,032; p<0.05). A statistically significant difference was found in mandible for necrotic bone presence (p<0.05). Necrotic bone presence was statistically significant in group B then control and group A (p=0.031; p<0.05). We concluded that increase rhBMP-2 dosage on extracted bone healing after ZOL treatment in ovarectomized rats can obtain new bone formation.