RESUMO
Objective To evaluate the effects of calcitonin and 1, 25 vitamin D on the bone loss in experimental periodontitis in rats. Methods A total of 125 male Wistar rats were randomly allocated to five groups according to the treatments during 8 weeks: normal control (group A, n=25), periodontitis(group B, n=25), calcitonin (group C, prepared in sterile saline at 2 mg/L, and 2μg/kg was administered daily, s.c. , n=25), 1,25 vitamin D (group D, prepared in corn oil daily at a concentration of 2 mg/L, and 2μg/kg was administered daily, p.o. , n=25), 1,25 vitamin D plus calcitonin (group E, n=25). The experimental model of periodontitis was induced by ligating floss around mandibular first molars with orthodontic wires in B,C,D and E groups. Five rats from each group were sacrificed, and the specimens were prepared at 2, 4, 6 and 8-week. The probing depth (PD) and alveolar bone level were observed. The serum bone-specific alkaline phosphatase (BALP) and osteocalcin (OC) were measured by enzyme-linked immunosorbent assay (ELISA) at 8-week in each group. Results The values of PD were significantly lower after 4, 6 and 8 weeks in E group than those of B, C and D groups (P＜0.05). The alveolar bone loss was significantly lower after 6 and 8 weeks in group E compared with that of B, C and D groups (P＜0.05). The serum levels of BALP and OC were significantly higher after 8 weeks in E group than those of B, C and D groups (P＜0.05). Conclusion The present study suggests that 1, 25 vitamin D and calcitonin can partially inhibit the alveolar bone loss induced by periodontitis. Especially, the application of both is more effective than either drug treatment alone.