RESUMO
PURPOSE: To examine and compare the expression of transforming growth factor-ß1(TGF-ß1) 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-ß1 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-ß1 expression was detected in the control group. After direct pulp capping with MTA, TGF-ß1 expression gradually increased and reached peak expression on 5 day. TGF-ß1 expression gradually decreased afterwards and reached normal on 21 day after direct pulp. TGF-ß1 was mainly expressed in neutrophils, odontoblasts cells, vascular endothelial cells and fibroblasts. The expression of TGF-ß1 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-ß1 expression increases at first and then decreases after direct pulp capping. The type of capping agents has an impact on the expression of TGF-ß1 after direct pulp capping. MTA enhances more TGFß-1 expression than CH 1, 3, 5, 7 and 14 days after direct pulp capping. Supported by Science and Technology Plan Project of Liaoning Province (2009225001-2).