Cellular viability and nitric oxide (NO) production by J774 macrophages in the presence of orthodontic archwires

To assess, in vitro, the cellular viability in a murine macrophage cell line J774 with 9 different orthodontic wires and to evaluate the effects of its NO production. To assess cellular viability by MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide assay in the cell line J774 with 9 different orthodontic wires and quantify NO production by these macrophages. Cell cultures were evaluated at 24, 48 and 72 hours. There was no significant difference of the means of cellular viability between the control and the group of wires in the respective time intervals. In the comparison with the control group, there was significant difference in the NO production in groups 1, 6, and 9 at 24 hours interval. Group 8 showed significant difference in relation to the control group at final time interval. Cellular viability in all groups was higher at the final time interval than at the initial time interval. This increase was significant in the control group. In the material groups, the final mean of cellular viability at 72 hours showed no significant difference when compared with the control group. NO production in all groups was higher at the final time interval than at the initial time interval. This increase was significant in the control group. In the material groups, the final mean of NO production at 72 hours was only significant in group 8 (beta-titanium) when compared with the control group.