High‐resolution 1 H NMR investigations of the capacity of dentifrices containing a “smart” bioactive glass to influence the metabolic profile of and deliver calcium ions to human saliva

Dentifrices containing H 2 O‐reactive bioactive glasses alleviate hypersensitivity in teeth via the blockage of open dentinal tubules. Here, the ability of two such products to release Ca 2+ ions into human saliva was investigated, together with their influence on the status of this biofluid's 1 H NMR‐detectable biomolecules. Human salivary supernatants were equilibrated with increasing volumes of those derived from each dentifrice (5.00 min at 37°C). These biofluids were also equilibrated at 37°C with a preselected quantity of the intact products (samples were collected at increasing timepoints). Salivary Ca 2+ concentrations were monitored by a 1 H NMR technique involving ethylenediamine tetra‐acetate addition and/or atomic absorption spectrometry. Added Ca 2+ ‐ and dentifrice supernatant volume (DSV)‐induced modifications to the salivary 1 H NMR profile were explored by spectral titration. Data acquired demonstrated added DSV‐dependent increases in salivary Ca 2+ concentrations and (Ca 2+ ‐independent) modifications to the intensities of selected salivary 1 H NMR signals, particularly those of the malodorous amines methyl‐, dimethyl‐, and trimethylamines, which were diminished by up to 80% of their prior values. Time‐dependent elevations in salivary Ca 2+ level were observed on equilibration with the intact dentifrices. Added Ca 2+ ions exerted a concentration‐dependent influence on a range of resonances (including those of citrate, succinate, pyruvate, and lactate). These data provide valuable information regarding the mechanisms of action of the products tested. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009