Comparison in Vitro Cytotoxicity between Zinc Chloride and Fluoride Mouthwash

Introduction: There are contrasting opinions among dental professionals as to use chemical agent in prophylaxis of calculus, tartar (mouthwash contains Zinc chloride) and dental caries control (mouthwash contains Fluoride). Any chemical agent that affects microbial cell may be expected to have some adverse effects against host cell. Objective: Comparing in vitro cytotoxicity between Zinc chloride and Fluoride mouthwash. Materials and Methods: We have used different type of concentrations of Zinc chloride and Fluoride mouthwash of 100%, 75%, 50%, 25% concentrations. Human keratinocyte (HaCat) cell line served as standard cell line. For MTT assay, cell layers were rinsed as for natural red(NR) assay and the MTT was added. Optical density of HaCat measured with Bio Red Micoroplate Reader at dual wavelength 490/655nm. For both tests, the optical density was directly proportional to the viability, i.e. the optical density, and the metabolic activity of cell population and inversely proportioned to the cytotoxicity of the cell and it depends on the contact time. Results: The data evaluated with of variance analysis followed by LSD Post hoc test. Comparing the control group, the Zinc chloride mouthwash of 100%, 75%, 50%, 25% concentrations were lower optical density scores. While in the Fluoride mouthwash of 100%, 75% concentrations were lower optical density scores, but in 50% and 25% concentrations had no differences ( p<0,05). Conclusions: All concentrations of the Zinc chloride mouthwash indicate toxic effect. The 100%, 75% concentrations of the Fluoride mouthwash also indicate toxic effect, but the 50% and 25% concentrations do not show any toxic effect. As general conclusion the cytotoxicity of Zinc chloride mouthwash is more toxic than Fluoride mouthwash.

Key words: cytotoxicity, mouthwash, density, viability