The effect of mineral trioxide aggregate on the mineralization ability of rat dental pulp cells: an in vitro study.

The aim of this study was to investigate the effect of mineral trioxide aggregate (MTA) on cell viability and mineralization ability of rat dental pulp cells. The pulp capping materials, such as MTA, Dycal (Dentsply Caulk, Milford, DE), and Superbond C&B (SB; Sun Medical, Shiga, Japan) were placed on transwell inserts and cultured with rat dental pulp cells. MTA and SB exhibited no cytotoxicity, whereas almost all cells had died after 72 hours of culture with Dycal. MTA significantly stimulated mineralization by 60% compared with the control. MTA and Dycal significantly upregulated by two-fold the level of bone morphogenetic protein (BMP)-2 messenger RNA expression compared with the control. Furthermore, MTA increased BMP-2 protein production by about 40%, whereas Dycal significantly reduced it. Although MTA and Dycal increased the concentration of extracellular calcium by about 0.4 mmol/L, SB had no effect. These results suggest that BMP-2 may play an important role in mineralization stimulated by MTA.