Comparison of the Cytotoxic Effects of Nanoparticulate and Microparticulate Calcium Sodium Phosphosilicate Mouthwashes on Human Gingival Fibroblasts: an in-vitro Study

Introduction:  This study sought to assess the cytotoxic effects of nanoparticulate and microparticulate calcium sodium phosphosilicate mouthwashes on human gingival fibroblasts (HGFs). Methods: This in vitro study was conducted on HGFs isolated and cultured in a 48-well plate containing standard culture medium for evaluation of four concentrations of the two mouthwashes at two time points plus a positive and a negative control group. The HGFs were exposed to 0.001, 0.01, 0.1 and 1 mg/mL concentrations of mouthwashes for 1 and 24 hours. Positive and negative control cells were exposed to saline and distilled water, respectively. Cell viability was assessed using the methyl thiazolyl tetrazolium (MTT) assay, and the number of viable cells was counted in triplicate using a cell counter after transfection (trypsin-EDTA 0.25%, 20 minutes) and exposure to trypan blue. The optical density (OD) values were read by ELISA reader and analyzed using the Kruskal-Wallis test. Results: Number of viable cells was not significantly different between the two mouthwashes at the two time points (P>0.05). At one hour, number of viable cells was higher in the nanoparticulate group while the number of viable cells in the microparticulate group was higher at 24 hours.  Conclusion: Nanoparticulate and microparticulate calcium sodium phosphosilicate mouthwashes have no cytotoxicity against HGFs. Cytotoxicity of the nanoparticulate mouthwash was less than that of the microparticulate mouthwash. Also, increased proliferation of fibroblasts was noted over time in both groups of mouthwashes.