In vitro evaluation of the cytotoxicity of two root canal sealers on macrophage activity.

Although some studies have been concerned with the cytotoxicity of endodontic sealers and their components, few have approached the effects of endodontic sealers on macrophage viability and activity. In this study the effect of two zinc oxide-eugenol-based sealers, freshly prepared or after setting for 24 h, was determined on macrophage activity in vitro. Sealers were placed inside a glass capillary tube and added to mouse-elicited macrophage cultures. Sealers did not affect macrophage viability; however, adherence to glass and phagocytosis were impaired. Moreover, nitric oxide production in response to activation with interferon-gamma was diminished, but interleukin-12 production in response to Listeria monocytogenes was not altered. Interestingly, freshly mixed and solid test samples had similar inhibitory activities. In conclusion, the tested sealers did not affect a pro-inflammatory response (interleukin-12 production) but had an inhibitory effect on the effector responses measured (phagocytosis and nitric oxide production).