Effects of Mineral Trioxide Aggregate on Cell Survival, Gene Expression Associated with Mineralized Tissues, and Biomineralization of Cementoblasts

The purpose of this study was to investigate the effects of mineral trioxide aggregate (MTA) on survival, mineralization, and expression of mineralization-related genes of cementoblasts. Immortalized cementoblasts (OCCM) were maintained with Dulbecco modified Eagle medium containing 10% fetal bovine serum. Methyl-thiazol-diphenyl-tetrazolium experiments were performed at 24 and 72 hours to evaluate bioactive components released by MTA (0.002-20 mg/mL) on the cell survival of OCCM. Von Kossa staining was used to evaluate biomineralization of OCCM Cells. Images of cementoblasts were taken on day 3 by using inverted microscopy. Gene transcripts for bone sialoprotein (BSP), OCN, collagen type I (COL I), and osteopontin (OPN) were evaluated on days 3 and 5 by using semi-quantitative reverse transcriptase polymerase chain reaction. The 20 mg/mL concentration of MTA was toxic for OCCM cells, whereas other concentrations of MTA tested exhibited similar cell numbers when compared with control group, and the 0.02 mg/mL concentration of MTA increased OCCM cell survival at 72 hours. Although an apparent decrease n mineralization was observed in the highest 3 concentrations of MTA used, 0.02 and 0.002 mg/mL concentrations of MTA induced greater biomineralization of OCCM cells than seen in the control. Moreover, increased BSP and COL I mRNA expression was observed at 0.02 and 0.002 mg/mL concentrations of MTA. MTA did not have a negative effect on the viability and morphology of cementoblasts and induced biomineralization of cementoblasts at the concentrations of 0.02 and 0.002 mg/mL. Based on these results MTA can be considered as a favorable material regarding cell-material interaction. (J Endod 2009;35:513-519)