Effect of Mineral Trioxide Aggregate on Rat Clonal Dental Pulp Cells: Expression of Cyclooxygenase-2 mRNA and Inflammation-related Protein via Nuclear Factor Kappa B Signaling System

Introduction: Recently, mineral trioxide aggregate (MTA) has been routinely used for endodontic treatment. It is well-known that MTA induced secondary dentin formation in pulp cavity when it was applied to dentin, whereas its cytotoxicities were unclear. The purpose of this study was to evaluate the effect of MTA on rat clonal dental pulp cells, RPC-C2A. Methods: This study was conducted to observe the response of RPC-C2A cells on MTA with reverse-transcriptase polymerase chain reaction, Western blot analysis, and enzyme immunoassay. Data were compared by analysis of variance. Statistical significance was established at P <.01. Results: MTA significantly caused an up-regulation of cyclooxygenase-2 (COX-2) and inducible form of nitric oxide synthase (iNOS) mRNA expression. Furthermore, MTA caused inhibitory kappa B (I kappa B) phosphorylation and translocation of nuclear factor-kappa B (NF-kappa B) subunits to nucleus. Curucumin, an inhibitor of NF-kappa B activation, suppressed MTA-induced COX-2 and NOS mRNA expressions, In addition, MTA increased the production of prostaglandin E-2 in comparison with the controls. Conclusions: MTA induces inflammation via NF-kappa B signaling system. (J Endod 2009;35:843-846)