Characterization of some denture cleansers

1. From comparison of calculated reaction times for homogeneous H2O2 aqueous decomposition containing alkali to the measured rates of H2O2 dissociation in the cleanser systems, it is apparent that the cleansers are further catalyzed either heterogeneously and/or homogeneously. Long-term O2 measurements indicate cleansers with O2 concentrations similar in magnitude to concentrations observed at early times. First-order reaction times, as well as the high solubility of O2 in water, can explain these high long-term O2 concentrations. 2. The process of catalyzing the H2O2 to O2 varies with cleanser product. Cleansers like Efferdent, Polident, and Kleenite exhibit high H2O2 concentration changes and high O2, suggesting the decomposition of H2O2 to O2. DOC exhibits high H2O2 concentration changes and low O2, suggesting the H2O2 decomposition via the perhydroxyl ion, HO2-. 3. The CO2-H2O system contributes to the aqueous chemistry of the slightly basic cleansers of Efferdent and Polident. Measured CO2 concentrations of these cleansers were high in comparison to the more basic cleansers of Kleenite and DOC. 4. Differentiation of the cleansers were made in terms of the Cl- concentration. Kleenite exhibited Cl- concentrations at least 10(2) times the concentrations found in Efferdent and Polident.