Abstract: Objective: To evaluate the effect of a local treatment of calcitonin on the alveolar fossa following tooth extraction in rats. Methods: Twenty-seven SD rats were randomly divided into three groups: control group, gelatin sponge group, and calcitonin+gelatin sponge group. The model of residual alveolar bone resorption was established by extracting the left mandibular incisor. Rats were sacrificed at 4, 8, and 12 weeks after operation. The alveolar fossae were assessed by CBCT, dual-energy X-ray, histology, TRAP staining, and immunohistochemistry. Results: At 4, 8 and 12 weeks, calcitonin+gelatin sponge rats showed less resorption of the residual alveolar ridge, better bone mineral density and bone mass than gelatin sponge rats and control rats, however there was no significant difference between gelatin sponge rats and control rats. The positive expression of calcitonin receptor, the number of TRAP-positive cells and RANKL/OPG ratio in the control group and gelatin sponge group were higher than those in the calcitonin+gelatin sponge group at 4 weeks. Conclusion: Local treatment of calcitonin at the site of alveolar fossae following tooth extraction could effectively inhibit the resorption of alveolar bone, which may be mediated through the combination of calcitonin and calcitonin receptor to inhibit osteoclasts.

Key words: calcitonin , bone resorption , alveolar fossa