Multicomponent evaluations of the oxidising actions and status of a peroxoborate-containing tooth-whitening system in whole human saliva using high resolution proton NMR spectroscopy

High resolution 1 H nuclear magnetic resonance (NMR) spectroscopy was employed to conduct a multicomponent investigation of the oxidation of salivary biomolecules by peroxoborate present in a tooth-whitening dentifrice formulation. The results acquired demonstrated that peroxoborate gave rise to the oxidative decarboxylation of the hydrogen peroxide scavenger pyruvate, a reaction generating acetate and C02 as products. Experiments performed on chemical model systems confirmed the oxidative consumption of pyruvate by dentifrice-derived peroxoborate, and also revealed that the salivary electron donors cysteine and methionine ( precursors to volatile sulphur compounds), wereoxidised to cystine and methionine sulphoxide respectively. The biochemical and periodontal significance of these results is discussed.