Fluoride varnish was effective at reducing caries on high caries risk school children in rural Brazil

Placebo controlled randomised controlled trial (RCT).

Recruited children were randomly assigned to either a treatment (5% NaF varnish, n = 198) or a control group (placebo, n = 181). Data on oral health habits and socio-demographic characteristics was collected from the children by trained interviewers. Diet information was collected using a seven day food frequency diary. Caries was assessed using the International Caries Detection and Assessment System (ICDAS).

The main outcome was decayed and filled surfaces (DFS) increment at 12 months.

Two hundred and ten (55.4%) children having one or two applications of fluoride varnish or placebo were available for follow-up at 12 months. At the baseline examination, the children in the treatment and control groups presented with on average 6.2 and 5.6 DFS, respectively (P < 0.001). At 12 months, the children in the varnish group showed significantly lower DFS increments than did children in the control group (10.8 versus 13.3; P < 0.007), with a preventive fraction (PF) of 40% (95% CI: 34.3-45.7%; P < 0.0001).

The results of this study suggest that applications of 5% NaF varnish can be recommended as a public health measure for reducing caries incidence in this high-caries-risk population.