局部应用地塞米松和维生素C对拔牙创骨愈合的影响研究

目的探讨局部应用地塞米松和维生素C对拔牙创骨愈合的影响。方法拔除40只Wistar大鼠的双侧上颌第一前磨牙，左侧填人浸泡地塞米松和维生素C的明胶海绵（观察侧），右侧仅填入明胶海绵（对照侧），分析处理后不同时间点的牙槽骨骨密度、牙槽嵴高度吸收值、牙周组织中碱性磷酸酶（ALP）活性和血管内皮生长因子（VEGF）的表达水平。结果①观察侧术后4周、6周和12周的牙槽骨骨密度均高于对照侧（P均〈0．05）；②术后6周和12周的牙槽嵴高度吸收值均低于对照侧（P〈0．05或P〈0．01）；⑧术后4周、6周和12周的牙周组织ALP活性和VEGF表达水平均高于对照侧（P均〈0．05）。结论局部应用地塞米松和维生素C可加速拔牙创的骨愈合，减少骨吸收，可能是通过上调Ⅰ型胶原和VEGF的表达来实现的。

Effects of local application of dexamethasone and vitamin C on bone heal- ing in tooth, extraction sites

Objective To explore the effects of local application of dexamethasone and vitamin C on bone healing in tooth extraction sites. Methods The first premolars of bilateral maxillary were removed in forty Wistar rats. The gelatin sponges after soaking in dexamethasone and vitamin C were filled in the left side （observed side）, while gelatin sponges alone were filled in the right side （control side）. At different time points after treatment, the bone mineral density of alveolar bone, height absorption of alveolar ridge, activities of alkaline phosphatase （ALP） and expression levels of vas- cular endothelial growth factor （VEGF） in the periodontal tissues were analyzed. Results ①The bone mineral densities of alveolar bone in observed sides were higher than those in control side at 4th （P 〈 0.05）, 6th （P 〈 0.05） and 12th （P 〈 0.01） weeks after treatment. ②The control side＇s height absorption values of alveolar ridge were lower than con- trol side at 6th （P 〈 0.05） and 12th （P 〈 0.01） weeks after treatment. ③Both activities of ALP and expression levels of VEGF of observed sides were higher than those of control side at 4th （P 〈 0.05）, 6th （P 〈 0.05） and 12th （P 〈 0.01） weeks after treatment. Conclusion The local application of dexamethasone and vitamin C can accelerate bone healing in tooth extraction sites and reduce bone resorption, which may be achieved by up-regulation the activities of ALP and expression levels of VEGF.