Fluoride varnish may be effective in preschoolers

BBO, Lilacs, Medline and the Cochrane library were searched.

Randomised or quasi-randomised controlled clinical trials (RCTs) or controlled clinical trials (CCTs) conducted in children up to six years of age undergoing any form of topical fluoride application reporting caries as an outcome were included. Articles in English, Spanish or Portuguese were included.

Data were extracted in duplicate and mean caries increment and prevented fraction was presented for each of the included studies. Meta-analysis was not performed owing to the heterogeneity of the data.

Eight trials conducted in four countries China, the United States, Poland and Sweden were included. Most of the studies were of poor methodological quality. They were also heterogeneous in relation to participants' previous caries experience, type of intervention administered to the control group, children's exposure to other sources of fluoride and varnish application interval. The absolute differences between caries incidences in the control and test groups ranged from 0.30 to 1.64 and the preventive fractions varied from 5% to 63%.

Fluoride varnish may be effective to decrease dental caries incidence in preschoolers, but more randomised clinical trials of better methodological quality are necessary to provide conclusive evidence in this respect.