Abstract:

Abstract:Objective To investigate the expression and distribution of cyclooxygenase-2 (COX-2) in periodontal tissues during experimental tooth movement in rats,and  study  the relationship between  COX-2 and vesscular reconstruction in experimental tooth movement process.Methods Thirty-five healthy Wistar rats were divided randomly into 7 groups on average:normal group and experimental groups for 1,3,5,7,14 and 21 d.A NiTi coil spring with 0.294 N mesial force was connected between first molars of maxillary and the upper incisors.The histological sections were stained with goat anti rat COX-2 antibody,and computer image analysis was used to study the expression of COX-2 in the periodontal tissues of rats.Results Pressure area:compared with normal group(134.75±5.25) the COX-2 expression in 1 d group (147.73±3.27)increased (P<0.05) after tooth movement and reached the maximum at 5 d(154.32±9.54).Tension area:compared with normal group,the COX-2 expression in 3 d group (139.16±5.01)increased( P<0.05) after tooth movement and reached the maximum at  7 d(159.46±7.48).There was no significant difference of COX-2 expression in pressure area and tension area bewteen 21 d group and normal group (P>0.05).
Conclusion The expression of COX-2 in  periodontal tissues during experimental  tooth movement increase,suggesting that COX-2 can promote the vascular reconstruction in periodontal tissues during orthodontic tooth movement.

Key words: experimental tooth movement, periodontium;cyclooxygenase-2, immunohistochemistry