Temporal changes in fluoride concentrations in salivary compartments after dentifrice use and professional fluoride...

This study evaluated temporal changes in fluoride concentrations in distinct salivary compartments, supernatant and sediment, up to 12 h after application of fluoridated products with different concentrations and delivery modes.

This short-term, parallel, randomized clinical trial included 40 participants allocated into four groups: dentifrice containing 1450 ppm F, dentifrice containing 5000 ppm F, acidulated phosphate fluoride (APF) gel, and fluoride varnish. Unstimulated saliva was collected at baseline and at 5, 30, and 60 min, and 4, 8, and 12 h after product application. TISAB-extractable fluoride concentrations were determined in salivary supernatant and sediment and compared using ANOVA, paired t-tests, and ANOVA followed by Dunnett's post hoc test.

For APF gel and fluoride varnish, no significant differences in measured fluoride concentrations were observed between salivary compartments. In contrast, for the 1450 and 5000 ppm F dentifrices, fluoride concentrations were consistently higher in the sediment at all time points. In the supernatant, treatments differed significantly at 5 and 30 min (p < 0.05), and from 1 to 8 h both dentifrices showed lower fluoride concentrations than APF gel and varnish. In the sediment, fluoride varnish resulted in higher fluoride concentrations than the other treatments (p < 0.05), except at 5 min.

fluoride concentrations in saliva varied according to salivary compartment, time after application, and product formulation. The sediment fraction retained higher fluoride concentrations under several experimental conditions, suggesting a role for the particulate phase in salivary fluoride retention. These findings provide new insights into fluoride kinetics and compartmental distribution in saliva, contributing to the understanding of fluoride behavior as a trace element in biological fluids.