The Expression Of STRO-1 In Periodontal Tissue Of Orthodontic Tooth Movement In Rats

The periodontium is an unusually complex tissue comprised of two hard (cementum and bone) and two soft (gingiva and periodontal ligament) tissues. Periodontal ligament stem cell (PDLSC) contained human PDL is a population of multipotent postnatal stem cells that can be isolated and expanded in vitro. Some findings show that postnatal PDLSCs are clonogenic,highly proliferative cells and capable of regenerating cementum/PDL-like tissues. Consequently,PDLSCs have potential for use in periodontal tissue regeneration.STRO-1 have been identified on a variety of mesenchymal stem cells.So we can identify and localize PDLSC in periodontal ligament using this cell-surface markers. It was very considerable to establish animal model in young SD rats for orthodontic tooth movement and research the roles and the principle of PDLSC.The study consists of two parts:1.Establishment of animal experimental model on orthodontic tooth movementObjective:To establish an animal model in rats for orthodontic tooth movement. Methods:35 young SD rats were used in the study. The rats were randomized into two groups.A coil spring was placed onto the incisor and first premolars in 30 rats.All animals were sacrificed after 1,3,5,7,10,14 days. Specimen was observed histological. Results:All of the animals were alive successfully after the experiment.During the movement the tooth are in prospective direction. Conclusion : The tooth movement was achieved impressively, and it is feasible and repeatable of experimental model on this study.2,The distribution and Changes of STRO-1 in periodontal tissue in rats during orthodontic tooth movementObjective:To observe the distribution and changes of STRO-1 in periodontal tissue in rats and analyze the role of PDLSC in the periodontal tissue remodeling during orthodontic tooth movement.Methods:The model of orthodontic tooth movement was established in young SD rats. The animals were sacrificed after 1,3,5,7,10,14 days. The distribution and changes of STRO-1 in the periodontal tissues of the first molar were observed by immunohistochemistry technology in the section. The optical density(OD)of STRO-1 was analyzed by image-pro plus6. 0 software. Results:Putative stem cells were identified in both normal group and hey were mainly located in the paravascular region. In experimental group ligament clusters of cells were also found in the extravascular region. Wider distributions were detected in sections of experimental ligament. Conclusion:These results indicate that PDLSC participates in the periodontal tissue remodeling during orthodontic tooth movement in multiple ways.