Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Background: Mineral trioxide aggregate (MTA) has been used in a variety of surgical and non-surgical endodontic applications. The aim of this study was to evaluate the gene expression and protein production of TNF-alpha, IL-1 beta and IL-6, as well as the gene expression of RANKL and OPG using both commercial and experimental MTA in macrophage cell cultures. Methods: Peritoneal macrophage cell culture was performed. Viability, gene expression of cytokines, RANKL and OPG, and protein levels in experimental- and commercial-grey MTA co-cultured with peritoneal macrophages was determined by tryptan blue, real time PCR and ELISA. Results: The expression of TNF-alpha for both commercial and experimental MTA was higher, while the expression of IL-1 beta and IL-6 was similar when compared to the negative control. At protein expression level, no differences were observed between the negative control and cements. RANKL did not show a significant improvement in gene expression when compared with the negative control, but OPG expression in cement samples was higher when compared to the negative control. Conclusions: This study suggests that commercial and experimental MTA promotes anti-inflammatory processes, as well as bone healing capacity.573284291Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [07/58796-4, 07/56731-2]