Optimization of a Validated Protocol That Determines Bioavailable Fluoride in Toothpastes.

ABSTRACT

A validated protocol used to determine how much of total fluoride is bioavailable in toothpaste formulations was evaluated if it could be simplified regarding the following parameters (1) concentration of the slurry (0.25-4%), (2) centrifugation speed (1,000-12,000 g) and time (1-10 min), and (3) incubation time for FPO32- ion hydrolysis and insoluble-F dissolution (15-60 min). Fresh and aged Na2FPO3/CaCO3 and fresh NaF/SiO2-based toothpastes were analyzed (n = 9). The improvements were the centrifugation at 1,000 g for 5 min is enough to separate insoluble-F and the time for FPO32- ion hydrolysis and insoluble-F dissolution can be shortened to 30 min.