Abstract: ［Abstract］ Objective〖HTSS〗〓To investigate the effect of bone morphogenetic protein2(BMP2) on periodontal regeneration after delayed replantation of avulsed tooth in rat.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓Sixteen male Wistar rats weighed 250 to 300 g were randomly assigned to a control group(n=8) and experimental group(n=8). The teeth were extracted and airdried for 1 hour. The root canals were endodontically treated and the root apexes were sealed with glass ionomer. In experimental group, BMP2 paste is applied to root surface of each tooth and replanted in the original socket. Teeth in control group is replanted without any surface treatment. After 8 weeks of replantation, the bone segment from the replantation site is obtained, decalcified and evaluated histologically.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓There was no statistically significant difference regarding the cementum regeneration, replacement root resorption and inflammatory root resorption in both groups(P＞005).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓The results indicate that the application of BMP2 may promote cementum regeneration and inhibit the inflammatory root resorption. However, the inhibitory effect was not significant in the delayed replantation of avulsed teeth.

Key words: tooth avulsion； tooth replantation, rats