Salivary fluoride levels after daily brushing with 5000ppm fluoride toothpaste: A randomised, controlled clinical trial.

Abstract

This study explored salivary fluoride levels following toothbrushing with 5000 and 1450ppm fluoride toothpaste and determined the decline in salivary fluoride levels following the return from 5000 to 1450ppm fluoride toothpaste. The study was a randomised, controlled double-blind parallel clinical trial (n=24/group) measuring salivary fluoride five times during a 3-week trial phase involving 2×/day use of 5000 or 1450ppm fluoride toothpaste, and five times during an ensuing 2-week wash-out phase where all participants used 1450ppm toothpaste. Salivary fluoride was measured using a fluoride electrode and data were analysed using multilevel mixed-effects linear regression. Baseline salivary fluoride geometric means were 0.014 and 0.016ppm for the 1450 and 5000ppm groups, while the values at the end of the trial phase were 0.023 and 0.044ppm, respectively. During the trial phase, except at baseline, differences between groups were statistically significant. The salivary fluoride levels for the 5000ppm group remained statistically significantly higher than for the 1450ppm group only at the first measurement in the wash-out phase (≈30h after the last 5000ppm brushing), indicating that higher salivary fluoride levels resulting from use of 5000ppm are sustained only as long as the brushing habit continues.