Low-fluoride dentifrice and gastrointestinal fluoride absorption after meals

A low- fluoride ( F) dentifrice has been recommended to reduce the risk of dental fluorosis, but its anti- caries efficacy is questionable compared with that of conventional dentrifices ( 1000- 1100 mu g F/g). The tested hypothesis was that conventional dentifrices might be safe if used soon after meals, since food interferes with F absorption. In a crossover, double- blind study, 11 volunteers ingested a dentifrice slurry containing 0 ( placebo), 550 ( low F), or 1100 mu g F/g in 3 gastric content situations: on fasting, or 15 min after breakfast or lunch. F was analyzed in saliva and 24- hour urine samples. The conventional dentifrice ingested after lunch resulted in only 10% higher F absorption than the low- F ingested on fasting. Analysis of the data suggests that the risk of fluorosis could be reduced by the use of either a low- F dentifrice or a conventional dentifrice, if toothbrushing occurred soon after meals.