Abstract:

Abstract：Objective To observe the dynamic expression of transforming growth factor-β1（TGF-β1）in rat dental pulp after direct pulp capping with mineral trioxide aggregate（MTA）and to evaluate the role of TGF-β1 on pulp injury and repair. Methods This study was conducted from October 2012 to March 2013 in the Central Laboratory of School of Stomatology，China Medical University. Twenty-eight female Wistar rats were included in this study. The first molars on one side of the maxilla and mandible were mechanically exposed and the exposed dental pulps were directly capped with MTA. The contralateral molars received no treatment and served as controls. The rats were sacrificed 1d，3d，5d，7d，14d，21d and 28d after direct pulp capping. TGF-β1 expression in pulp tissue was detected with immunohistochemical staining. Results No TGF-β1 expression was detected in the control group. After direct pulp capping with MTA，TGF-β1 expression gradually increased and reached peak expression on 5d post-direct capping （P < 0.05）. TGF-β1 expression gradually decreased afterwards and reached normal stain on 21d post-direct pulp capping. TGF-β1 was mainly expressed in neutrophils，odontoblasts cells，vascular endothelial cells and fibroblasts. Conclusion After direct pulp capping with MTA，TGF-β1 expression increased at first and then decreased. Our results suggest that TGF-β1 expression is related to the process of dental pulp repair.

摘要：

目的 观察大鼠磨牙应用矿物三氧化物凝聚体（MTA）直接盖髓术后牙髓组织中转化生长因子-β1（TGF-β1）的表达变化及其在牙髓损伤修复中的作用。方法 本研究于2012年10月至2013年3月在中国医科大学口腔医学院中心实验室进行。28只雌性Wistar大鼠第一磨牙机械穿髓后用MTA直接盖髓，并以对侧第一磨牙为对照，分别于术后1、3、5、7、14、21、28 d处死动物并取材（每次处死4只），进行免疫组化染色，观察TGF-β1在牙髓组织的动态表达和定位情况，用图像分析软件测定各组标本中TGF-β1阳性染色的光密度值。结果 在正常牙髓组织中TGF-β1基本无表达，MTA直接盖髓后TGF-β1表达强度呈先升高后降低的基本变化，其中盖髓后5 d 的TGF-β1表达最强，21 d时接近正常水平。表达主要位于盖髓剂下方中性粒细胞、成牙本质细胞、成纤维细胞和血管内皮细胞。结论 MTA直接盖髓后，TGF-β1可能参与牙髓的损伤修复过程。

关键词: 转化生长因子-&beta, 1, 矿物三氧化物凝聚体, 直接盖髓术, 损伤修复, 大鼠