2种盖髓剂行大鼠磨牙直接盖髓后转化生长因子β1表达的比较

目的: 观察氢氧化钙(calcium hydroxide, CH)和矿物三氧化物凝聚体(mineral trioxide aggregate, MTA)行大鼠磨牙直接盖髓后转化生长因子β1(transforming growth factor-β1, TGF-β1)的表达变化, 比较2种盖髓剂对牙髓损伤修复中TGF-β1表达的影响。方法: 建立28只雌性大鼠CH和MTA第一磨牙直接盖髓模型, 在观察时间点1、3、5、7、14、21、28 d处死大鼠取材, 进行TGF-β1免疫组化染色, 用图像分析软件IPP6.0测定各组标本中TGF-β1阳性染色的平均吸光度值。采用SPSS 13.0软件包对数据进行Dunnett t检验和配对t检验。结果: 在正常牙髓组织中, TGF-β1基本无表达;CH和MTA直接盖髓后不同时间, TGF-β1表达强度呈先升高后降低的变化, 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的成纤维细胞、成牙本质细胞、血管内皮细胞、中性粒细胞等。2种盖髓剂在盖髓后1、3、5、7、14 d , TGF-β1的表达强度有显著差异(P<0.05)。结论: 盖髓剂直接盖髓后, TGF-β1表达强度呈先升高后降低的变化, 不同盖髓剂直接盖髓对牙髓损伤修复中TGF-β1的表达有一定影响。在直接盖髓后的1、3、5、7、14 d, MTA比CH更能促进TGF-β1的表达。

Comparison of expression of transforming growth factor-β1 in rat dental pulp during direct pulp capping with 2 capping agents

PUPPOSE: To examine and compare the expression of transforming growth factor-β1(TGF-β1)in rat dental pulp after direct pulp capping with calcium hydroxide(CH)and mineral trioxide aggregate(MTA). METHODS: The model of direct dental pulp capping after first molars was established in 28 female Wistar rats with CH and MTA.The rats were sacrificed 1, 3, 5, 7, 14, 21 and 28 days after direct pulp capping. TGF-β1 expression in pulp tissues were measured with immunohistochemical staining.The data was analyzed by Dunnett t test and paired t test with SPSS 13.0 software package. RESULTS: The results showed that 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 5 day. TGF-β1 expression gradually decreased afterwards and reached normal on 21 day after direct pulp. TGF-β1 was mainly expressed in neutrophils, odontoblasts cells, vascular endothelial cells and fibroblasts. The expression of TGF-β1 was significantly different between 2 capping agents 1, 3, 5, 7, 14 days after direct pulp capping (P<0.05). CONCLUSIONS: The results suggest that TGF-β1 expression increases at first and then decreases after direct pulp capping. The type of capping agents has an impact on the expression of TGF-β1 after direct pulp capping. MTA enhances more TGFβ-1 expression than CH 1, 3, 5, 7 and 14 days after direct pulp capping.