Effects of single high-dose systemic vitamin D injection to dentin-grafted bone defects in osteoporotic rats

Abstract

Aim: Osteoporosis is a metabolic bone disease posing a public health issue worldwide. Studies showed that dentine can be an alternative bone graft material in bone defects. The purpose of this study is to investigate the potential of the intraperitoneal administration of vitamin D on dentine grafted critical-sized cortical bone defects in osteoporotic rat model. Material and Methods: Twenty-four rats were underwent bilateral ovariectomy and 6 weeks after ovariectomy osteoporotic rats model were obtained and divided into three groups: Group A; Dentine-D vit, Group B; Dentine and Group C (control). A 5-mm diameter critical- size defect was created in the calvarium of each animal. In Group C, untreated control defects. In Group Dentin, defects were filled with particulate human dentine. In Group Dentin-D vit, defects were filled with particulate human dentine and rats were injected intraperitoneally a single high dose (50.000 U.I./kg) vitamin D. All animals were euthanized at 28 days postoperative. Results: New bone formation was evaluated by histologic and immunohistochemical analysis. Histologic analysis showed that Group Dentin-D vit and Dentin had significantly more new bone at 4 weeks compared with group C. According to immunohistochemical analyses, in group Dentin-D vit, BMP2 staining areas and density were statistically higher than Control group. TGF-β level differences between groups Dentin-D vit and Dentin were statistically significant. Group C had a significantly lower TGF-β grade than the other groups. The osteopontin staining areas in group Dentin-D vit were statistically higher grade than in group Dentin and group C. The difference between groups Dentin and C was also statistically significant. Conclusion: Intraperitoneally injected single high dose vitamin D had positive effect on dentine graft and bone formation.