Population: pregnant women for preventing dental caries in the primary teeth of their children
Setting: USA
Intervention: fluoride supplementation (tablets)
Comparison: placebo

Children with caries in the primary teeth at 3 years

RR 1.46
(0.75 to 2.85)

938
(1 RCT)

⊕⊝⊝⊝
VERY LOW^{1, 2}

At 5 years RR 0.84
(0.53 to 1.33)

Decayed or filled primary tooth surfaces at 3 years

‐

938
(1 RCT)

⊕⊝⊝⊝
VERY LOW^{2, 3}

Not significant at 5 years

Fluorosis (maxillary teeth) at 5 years

RR 1.79
(0.95 to 3.40)

798
(1 RCT)

⊕⊝⊝⊝
VERY LOW^{1, 2}

Fluorosis in mandibular teeth at 5 years RR 0.89
(0.35 to 2.29)

*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)

CI: confidence interval; MD: mean difference; RCT: randomised controlled trial; RR: risk ratio

GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect