Methods: In an in vivo, crossover, blind study, 12 volunteers brushed their teeth during 1 min with 1 g of a toothpaste containing MFP/CaCO3 (Sorriso®, 1450 ppm F as labeled). After brushing, a rinse with 10 mL of deionized water was made. Unstimulated saliva was collected before brushing and after 5, 15, 30, 45 and 60 min. Ionic F (F-) and total soluble F (TSF), which corresponds the sum of F as ion and as MFP were determined after acid treatment of salivary samples to hydrolyze MFP. Fluoride was determined using an ion selective electrode. Concentration of fluoride as MFP was calculated by subtracting F- from TSF.
Results: Before brushing, TSF concentration in saliva was 0.03±0.02 ppm F. After 5 min, MFP and F- concentration increased to 4.1±3.6 and 1.6±1.1 ppm F, respectively. The percentage of MFP in relation to TSF decreased with time, from 69.9±13.2% at 5 min to 15.6±12.8% at 60 min, indicating continuous MFP hydrolysis. Sixty min after brushing, TSF concentration was 0.06±0.04 ppm F.
Conclusion: The results suggest that the top-selling MFP/CaCO3 Brazilian toothpaste is able to increase MFP concentration in saliva that is continuously hydrolyzed releasing F- to interfere with dental caries process.