Evaluation of the total fluoride intake of 4-7-year-old children from diet and dentifrice.

This study measured the total daily fluoride (F) intake of 21 children, living in Bauru, a fluoridated community. F intake from diet (D) and dentifrice (B) was determined for 2 groups of children: A (4-5-year-old) and B (6-7-year-old). The method of 24-hour duplicate diet was used. F ingested from dentifrice was indirectly obtained, subtracting the amount expelled and the amount left on the toothbrush from the amount initially loaded onto the brush. F analysis was carried out with the ion specific electrode (Orion 9409), after hexamethyldisiloxane-facilitated diffusion. The amount of F intake from D and B was divided by the child weight and total intake (T) was calculated by adding D and B. Data were analyzed by Student’s "t" (p<0.05) test and by linear regression. Results (mean ± SD, mg F/Kg body weigh) of T, D and B were, respectively: 0.056±0.040; 0.018±0.12; 0.037±0.038 for all children; 0.055±0.026; 0.021±0.014; 0.034±0.027 for Group A and 0.057±0.052; 0.016±0.010; 0.041±0.046 for Group B. There was a strong positive correlation between the amount of dentifrice used and the amount of fluoride ingested (r = 0.92, p<0.0001). One-third of the children analyzed were exposed to a F dose above 0.07 mg / Kg body weight, which is recommended as the upper limit of daily F intake. Dentifrice was the main source of F ingested by children with percentages of 57.43 ± 29.02 for all children; 56.49 ± 31.82 for group A; and 58.29 ± 27.78 for group B. No significant differences were found between the 2 groups.