In vivo fluoride concentrations measured for two hours after a NaF or a novel two-solution rinse

The concentrations of fluoride in various samples from the oral environment were measured at timed intervals after a novel rinse or a NaF rinse, both containing a total of 12 mmol/L (228 ppm) fluoride. The novel rinse consisted of two solutions mixed just before application: Part A contained calcium chloride and sodium acetate; part B contained a hydrolyzable source of fluoride (sodium hexafluorosilicate) and sodium phosphate. Samples were obtained as follows: Single-site plaque-fluid samples were obtained by centrifugation of first-molar plaque; pooled whole-plaque samples were collected from second molars; centrifuged, pooled whole-saliva was collected by vacuum. All samples were analyzed by micro-analytical methods. Results showed that, compared with NaF, the two-solution rinse produced significantly higher salivary fluoride concentrations, plaque-fluid fluoride concentrations, and acid-extractable fluoride in the whole plaque by factors of about 4, 2, and 6, respectively, at 120 min. The results of this study suggest that the new rinse may provide a greater cariostatic effect at the same fluoride dosage than does a NaF rinse.