完全性牙脱位是临床常见且预后较差的一类牙外伤疾病，除了有活性的牙周膜组织的损伤外，松牙固定方式和咬合加载时机因明显影响牙周组织的受力方式而成为影响其预后的主要因素。尽管课题组前期已证实PRF在优化PDLSCs微环境方面具有显著优越性，但咬合力载荷促进脱位牙牙周再生的机制仍不清楚。以往研究表明，正畸力能够通过改变牙周微循环来影响牙周改建，提示牙周组织对力学刺激的反应可能是以牙周膜微循环状态为标志的。因此，本项目拟在前期工作的基础上，以脱位再植牙牙周膜微循环重建特点与机制为突破口，综合利用细胞力学、分子生物学和iTRAQ蛋白分析及动物实验等方法，揭示牙周膜微循环重建在咬合力刺激促脱位再植牙牙周修复和改建过程中的作用及其机制，并深入探究力学加载与PDLSCs/PRF协同作用下牙周膜血管生长与新生的分子机理，从微循环角度完善脱位再植牙牙周愈合的机理，并从生物力学角度为促进其牙周愈合提供新的思路。

Tooth avulsion is one of the most severe types of dental trauma with poor prognosis. Beside of periodontal ligament (PDL) cells necrosis, the form of fixation and the time of occlusal loading are considered to be key factors for periodontal healing of avulsed tooth, for both of which might affect the mechanical sensitivity of PDL tissues. In previous studies, we have demonstrated that the use of platelet-rich fibrin (PRF) or the combination of PRF and periodontal ligament stem cells (PDLSCs) could significantly promote the periodontal healing of avulsed tooth. However, the effect of fixation and the time of occlusal loading on periodontal healing was still unclear. Previous studies have shown that the orthodontic force could influence the periodontal microcirculation, which was connected with the reconstruction of PDL. We hypothesized that the state of periodontal microcirculation is the sign of PDL tissues in response to mechanical stimuli. Hence, on the basis of our previous studies, this project takes the reconstruction of periodontal microcirculation as breakthrough to explore the relationship of occlusive force, microcirculation and periodontal healing of avulsed tooth, as well as the molecular mechanisms of that. The whole project is expected to reveal the molecular mechanism of angiogenesis and vasculogenesis of PDL tissues, and provide a new strategy and method for avulsed tooth to obtain ideal periodontal healing.