The effects of fluocinolone acetonide on human cultured dental pulp cell in vitro

Abstract

The purpose of treatment of pulpal exposure is to preserve vitality, healthy and promote healing of exposed pulp tissue. Fluocinolone acetonide (FA) may have a potential to promote tissue healing. The aim of this study was therefore to investigate the effects of FA on human cultured dental pulp cell in vitro. The MTT assay was performed to examine both cytotoxicity and prolifration of FA at 24, 48 and 72 hours. The results revealed that FA (0.1 to 50 [mu]M) had no cytotoxicity effect. In addition, these doses also stimulated cell proliferation. There was a significant increase of cell proliferation at low concentrations (0.1 and 1 [mu]M) after 48 hours (p<0.05). However, all doses of FA showed statistically significant difference in cell proliferation at 72 hours (p<0.05). The effect of FA on fibronectin synthesis was examined by Western blot analysis from cell extracted for 48 hours. The results showed that FA stimulated the synthesis of fibronectin in reverse dose-dependent manner. The Western blot analysis was performed to examine the effect of FA on type I collagen synthesis at 5 days. The result showed that 1 and 10 [mu]M of FA significantly stimulated the synthesis of collagen for about 2-fold (p<0.05). The result was confirmed by reverse transcription polymerase chain reaction (RT-PCR) which indicated that 1 [mu]M FA could significantly induce the expression of type I collagen mRNAs for about 2.8 times (p<0.05). The activity of alkaline phosphatase was detected at 24 and 72 hours and showed no statistically significant difference in any group at 24 hours (p>0.05). However, after 72 hours all doses of FA decreased alkaline phosphatase activity in a dose-dependent manner. Long term cultures were done to examine the in vitro calcification. After 28 days, the result showed no difference between FA-treated groups and the controls. These results demonstrated that FA enhances the effect on proliferation, fibronectin and type I collagen synthesis but not in calcification process. The results suggested that FA may be the potential substance as a pulp capping material.