Cytotoxicity assessment of zirconia-reinforced experimental nanohybrid dental composite using MTT assay

Abstract

The physical properties of experimental nanohybrid dental composite (NHDC) have been successfully enhanced by the use of nano-sized zirconia as a reinforcement filler. The study aims to assess the cytotoxicity of this newly developed zirconia-reinforced experimental NHDC on the L929 mouse fibroblasts cell line using MTT assay. The zirconia-reinforced (0, 3, 5 and 10 wt.%) experimental NHDCs were fabricated into disc-shaped and ground to powder form. The powder was diluted in complete Dulbecco’s Modified Eagle Medium and serially diluted five times. Then the dilution assays were incubated for 24, 48 and 72 hours with the 80% confluence fibroblasts cells in 96-well cell culture plates, followed by MTT assay. The experiment was carried out in six replicates and repeated three times. The cytotoxicity effect of NHDC was assessed based on the IC50 value. The nonparametric Kruskal-Wallis test was used for comparing more than two groups of variables. Significant level was set at p = 0.05. The zirconia-reinforced experimental NHDCs were found to be non-cytotoxic with the cell viability of all sample concentrations and incubation periods were above 50% when assessed on the L929 mouse fibroblasts cell line using the MTT assay.