The influence of rinsing routines on fluoride retention after toothbrushing.

OBJECTIVE: An important determinant of the anticaries effect of brushing with a fluoride dentifrice is the retention of fluoride in the oral fluids. This study measured the influence of various post-brushing rinsing routines on fluoride retention.

SETTING: The Faculty of Odontology, Göteborg University, Sweden.

SUBJECTS: Twenty-one healthy dental students, aged 23 +/- 2 yr.

DESIGN: A randomised, cross-over protocol, comparing various post-brushing rinsing procedures, with the following variables: volume of rinsing water (5 mL vs. 10 x 3 mL) and duration of rinsing (10 vs. 60 s). Samples of whole saliva, interdental fluid and interdental plaque were analysed for fluoride content.

RESULTS: The duration of rinsing did not influence fluoride retention in whole saliva, interdental fluid or interdental plaque. Rinsing with a higher volume of water substantially decreased fluoride retention in all samples.

CONCLUSION: Brushing with a fluoride dentifrice should be followed by rinsing procedures which enhance the retention of fluoride. Rinsing with large volumes of water decreases fluoride retention in the oral fluids, and should be discouraged.