Effect of Different Toothbrushing Routines on Interproximal Fluoride Concentration

This study aimed to evaluate the effect of different toothbrushing routines and different kinds of toothpaste on the interproximal fluoride concentration after toothbrushing and its clinical relevance to the recommendations given to patients regarding the process of toothbrushing. Eight adults participated a total of 8 times in order to test different toothbrushing routines with different amounts of toothpaste (1 or 2 cm), durations (1 or 2 min) and amounts of water after toothbrushing (10 or 20 mL). An additional 8 adults participated 6 times in total to test different forms of toothpaste administration (paste, gel and foam) with different amounts of water after toothbrushing (no rinsing or 10 mL). Interdental saliva samples were collected from proximal sites 25/26 and 46/45 using small paper points, before and up to 60 min after toothbrushing. The fluoride concentration was measured by an ion-specific electrode. The area under the curve, saliva fluoride concentration versus time, was calculated. Differences between the groups were tested by ANOVA with Tukey's multiple comparisons test. An increase in fluoride concentration of 47.2% was observed when the amount of toothpaste increased from 1 to 2 cm (p < 0.01), 26.8% when increasing the duration from 1 to 2 min (p < 0.01) and 41.2% when reducing the amount of water rinsing from 20 to 10 mL (p < 0.01). The paste and gel resulted in higher fluoride concentration (p < 0.01) compared with foam. These findings suggest that the amount of toothpaste, the duration and the amount of water have a significant effect on fluoride concentration after toothbrushing. Furthermore, despite the lower amount of fluoride, the gel gives almost the same fluoride concentration after toothbrushing as the toothpaste. The results confirm the importance of giving clear advice to patients regarding the process of toothbrushing.