Fluoride retention in saliva following toothbrushing using different types of fluoridated dentifrices containing 1500 ppm F of NaF and MFP

PurposeThis crossover study was carried out to evaluate the influence of two different types of fluoridated dentifrices containing sodium fluoride (NaF) and sodium monofluorophosphate (MFP) on salivary fluoride levels after toothbrushing.MethodsEight consenting individuals (average age 36.4 years) brushed their teeth in the same manner using a paste type of dentifrices (0.5 g) containing 1500 ppm F. Following toothbrushing for 2 min, they spat out once and rinsed their mouths with 15 mL of distilled water for 5 s. Resting saliva samples were collected for 3 min each at different time intervals; 5 min, 10 min, 15 min, 30 min, 60 min, 120 min, and 180 min following the mouth rinsing. Fluoride concentrations in saliva samples were determined using a fluoride ion specific electrode. Then we compared those of dentifrices, in regard to salivary fluoride concentrations in each individual. The area under the curve (AUC) of fluoride was calculated using a graph on which the horizontal base line represents sampling time and the vertical scale represents fluoride concentration.ResultsStatistical differences (p < 0.05) were shown in the fluoride concentrations [ppm, mean ± standard deviation (SD)] between NaF and MFP dentifrices at 5 min, 10 min, 60 min, 120 min, and 180 min after the rinsing. The AUC (ppm･minute, mean ± SD) during the whole experimental period showed statistical differences (p < 0.05) between NaF (49.5 ± 26.4) and MFP (24.6 ± 8.5).ConclusionThe results indicated that the NaF type of dentifrice retains more fluoride in saliva than that of MFP.