Abstract: Objective To compare the difference of the osteoclastic factors expression between the regenerated periodontal tissue and the healthy periodontal tissue under orthodontic compressional stress. The periodontal tissue was regenerated with the modified biaphasic calcium phosphate(BCP) as scaffold and bone marrow mesenchymal stem cells(BMSCs) as seed cells. To further investigate the possibility of orthodontic tooth movement after periodontal tissue regeneration. Methods Six male beagle dogs were grouped as 1week group,2week group and 4week group randomly. The first premolars were extracted and periodontal defects were made on the mesial aspect of the second premolar. The BMSCs from the dogs were cultured and seeded onto the modified BCP. In experimental group,the BMSCsmodified BCP complex was implanted into periodontal defects in the right upper and left lower quadrant. After 20 weeks of recovery,orthodontic compressional stress was initiated with 1.47 N force. Selfcontrolled experiment was applied,and the other two quadrants were set as 0week group without orthodontic force and control group without neither surgery nor orthodontic force,alternatively. Then two dogs were sacrificed after 1,2 and 4 weeks,and the expressions of NFATc1 and CathK were detected by RealTime PCR and WesternBlot. Results In experimental group,the expression of NFATc1 and CathK in periodontal tissues increased from 0 week to 2 weeks and decreased till 4 weeks. There were no significant differences in expression of these two osteoclastassociate transcript factors between two groups. Conclusions The expression of osteoclastic factors in regenerated periodontal tissue made no difference from that in the healthy periodontal tissue,which brings about the possibility of orthodontic tooth movement after periodontal tissue regeneration.

Key words: biaphasic calcium phosphate, periodontal tissue regeneration, osteoclast, NFATC1, CathK, beagle dogs