The effects of extended polymerization time for different resin composites on reactive oxygen species production and cell viability

Purpose: The present study was conducted to determine oxidative stress and cell viability after contact with resin composites polymerized for different times.Methods: Disk-shaped specimens of Admira Fusion, Ceram X One Universal, Solare x and Filtek Z550 (n = 12) were prepared, and two subgroups with polymerization times of 20 and 40 s were employed. The specimens were incubated with mouse fibroblast cells for 48 and 72 h, and changes in reactive oxygen species (ROS) production and cellular viability were determined by an assay with a cell-permeable fluorescent dye, 2’,7’-dichlorodihydrofluorescein diacetate (H2DCF-DA), and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, respectively.Results: At 72 h, ROS production in the presence of Admira Fusion polymerized for 40 s was reduced relative to that in the presence of Admira Fusion polymerized for 20 s (P < 0.05). Cell viability was maximal in the Admira Fusion and Solare x groups and there was no difference relative to the control group at 48 h. Cell viability was higher in the Admira Fusion and Solare x groups polymerized for 40 s than for the same materials polymerized for 20 s at 72 h (P < 0.05).Conclusion: Extension of the polymerizaton time has a material-specific effect and may be used as a strategy to increase the biocompability of resin composites.