Objective: The aim of this study was to assess (by direct determination) the fluoride (F) exposure from ingested toothpaste among 4-5-year-old Malaysian children.
Methods: This was part of a larger study to determine fluorosis status and F exposures. A total of 1343 10-11-year-old subjects were sampled by two-stage systematic random sampling for assessment of fluorosis. Two hundred 4-5-year-old siblings of these index subjects were sub-sampled for determination of F exposures from ingested toothpastes and other sources. Estimations of F ingested from toothpaste (FI) was made by the method of difference between 'F in toothpaste taken for use' and the 'F in toothpaste used but not swallowed', by the duplicate technique under normal home conditions. F ions were determined with the combination selective ion electrode.
Results: The subjects ingested 32.9% of the toothpaste placed on the brush. Fluoride exposure from ingested toothpaste was highly variable and the mean was 426.9 +/- 505.5 microg (SEM 38.9)/48 h, or 213.5 microg/day and 131.9 microg per brushing.
Conclusions: The amount of ingested fluoride (FI) per brushing in this study was the lowest of all studies reporting this parameter and was within the pea-size range of 125-250 microg. Because of the highly statistically significant correlations between the FI from toothpaste and the amount of toothpaste dispensed (Pearson's correlation coefficient 0.647, P = 0.000), parents should assume responsibility for placement of toothpaste and limit the amount of toothpaste used.