Fluoride ingestion from toothpaste and diet in 1- to 3-year-old Brazilian children.
OBJECTIVE
This study estimated the total daily fluoride intake of 1- to 3-year-old children from diet and dentifrice. The constituents of the diet were divided into solids, water, milk, and other beverages, which were analyzed separately. The correlation between fingernail fluoride concentrations and the total daily fluoride intake by children was also investigated.


METHODS
Thirty-three children, living in a fluoridated area, participated in the study. Fluoride intake from diet was monitored by the 'duplicate plate' method, investigating the different constituents of the diet. Fluoride ingested from dentifrice was determined by subtracting the amount of fluoride recovered after brushing from the amount originally placed onto the child's toothbrush. Fingernails were clipped and collected on three occasions. Fluoride was analyzed with the ion-specific electrode, after hexamethyldisiloxane-facilitated diffusion. Data were tested by anova and Tukey's post hoc tests, Student's t-tests and linear regression (P < 0.05).


RESULTS
Mean (+/-SD) fluoride intake from diet and dentifrice was 0.025 +/- 0.013 and 0.106 +/- 0.085 mg/kg body weight/day, respectively, totaling 0.130 mg/kg body weight/day. A strong positive correlation (r = 0.971, P < 0.0001) was seen between the amount of dentifrice loaded onto the brush (0.49 +/- 0.30 g) and the amount of fluoride ingested during each tooth brushing (0.59 +/- 0.45 mg). Among the constituents of the diet, water and milk had a significantly higher contribution to the fluoride intake (0.18 +/- 0.11 mg/day, P < 0.0001), when compared with solids (0.07 +/- 0.05 mg/day) and other beverages (0.07 +/- 0.04 mg/day). Mean (+/-SD) fingernail fluoride concentration on the three dates of collection was 3.11 +/- 1.14, 2.22 +/- 1.47 and 3.53 +/- 1.40 mug F/g. There was no significant correlation between fingernail fluoride concentration and the total fluoride intake.


CONCLUSIONS
Most of the children are exposed to a daily fluoride intake above the suggested threshold for dental fluorosis. The dentifrice alone is responsible for an average of 81.5% of the daily fluoride intake, while among the constituents of the diet, water and milk are the most important contributors. In addition, small variations in daily fluoride intake cannot be detected in fingernails.
de Almeida
Beatriz Simões
BS
Bauru Dental School, University of São Paulo, Bauru, Brazil.
da Silva Cardoso
Vanessa Eid
VE
Buzalaf
Marília Afonso Rabelo
MA
D000818:Animals; D001628:Beverages / Q000032:analysis; D001835:Body Weight; D001938:Brazil; D002327:Cariostatic Agents / Q000008:administration & dosage* / Q000032:analysis; D002675:Child, Preschool; D003802:Dentifrices / Q000008:administration & dosage / Q000032:analysis; D004032:Diet; D005247:Feeding Behavior; D005260:Female; D005457:Fluoridation; D005459:Fluorides / Q000008:administration & dosage* / Q000032:analysis; D005504:Food Analysis; D006801:Humans; D007223:Infant; D008297:Male; D008892:Milk / Q000737:chemistry; D009262:Nails / Q000737:chemistry; D014099:Toothbrushing; D014100:Toothpastes / Q000008:administration & dosage* / Q000032:analysis; D014867:Water / Q000737:chemistry; D014881:Water Supply / Q000032:analysis
D002327:Cariostatic Agents; D003802:Dentifrices; D014100:Toothpastes; D014867:Water; D005459:Fluorides