Abstract: Abstract Objective:The goal of this study was to investigate the effect of 1,25 Vitamin D and Calcitonin on experimental periodontitis through the animal experiment.Methods:40 male Wistar rats were allocated to four experimental groups according to the treatment received during 8 weeks: periodontitis group(group A), calcitonin (group B), 1,25 Vitamin D(group C), 1,25 Vitamin D plus calcitonin(group D).Eight weeks later,the animals were sacrificed and the specimens were prepared for histological analysis.clinical assessment included probing depth(PD) and aleolar bone loss(ABL).Histological examination included periodontal membrane fiber and alveolar bone inflammatory.The serum BALP and OC were measured by ELISA method.Results:Intergroup comparisons demonstrated that group D might reduce the probing depth and the alveolar bone loss was decreased compared with group A,B and C (P<0.05).The serum BALP and OC in group D was higher than group A , B and C.Conclusions:The present study demonstrates that after taken 1,25vitaminD and Calcitonin for 8 weeks experimental periodontitis rats could decreased alveolar bone loss.

Key words: periodontitis, Calcitonin, 25 Vitamin D, osteoblast