Background: Dental caries and its consequences pose important problems in all industrialized societies and in a large number of developing countries. There is a social class gradient in dental caries; caries levels are lower in higher social class children than in lower classes, and these differences are consistent in industrialized and in urbanized developing countries. Fluoride toothpastes have been widely used for over three decades for the prevention of dental caries.

Objectives: To determine the effectiveness and safety of fluoride toothpastes in preventing dental caries in children and to examine whether their effect is influenced by the initial level of caries severity, background exposure to other fluoride sources, fluoride concentration and application features; to examine the potential of fluoride toothpastes for reducing socioeconomic inequalities in health among children.

Methods: Relevant randomized/quasi-randomized trials were identified without language restrictions by searching multiple databases, reference lists of articles, journals, and by contacting selected authors and manufacturers. Trials with blind outcome assessment, comparing fluoride toothpaste with placebo or no treatment for at least one year, involving children under 17 years of age were selected. Inclusion decisions, quality assessment and data extraction were duplicated in a random sample of one third of studies, and consensus achieved by discussion or a third party. Random effects meta-analyses were performed where data could be pooled. Potential sources of heterogeneity were examined in random effects meta-regression analyses. The main outcome was caries increment measured by the change in decayed, missing and filled permanent tooth surfaces (D(M)FS). The primary measure of effect was the prevented fraction (PF) that is the difference in mean caries increment between the treatment and control groups expressed as a percentage of the mean increment in the controls.

Results: There were 74 studies included. For the 70 that contributed data for meta-analysis (involving 42,300 children) the D(M)FS pooled PF was 24% (95% CI, 21% to 28%; p < 0.0001). There was substantial heterogeneity, confirmed statistically (p < 0.0001), but the direction of effect was consistent. The effect of fluoride toothpaste increased with higher initial caries levels (0.8% increase in PF per unit increase in caries, 95% CI, 0.3 to 1.2%; p=0.002), higher concentration of fluoride (11% increase in PF per 1000 ppm F, 95% CI, 3 to 18; p=0.005), and supervised brushing (10% lower PF with unsupervised brushing, 95% CI, -16 to -3%; p=0.004), but was not influenced by exposure to water fluoridation.

Conclusions: Fluoride toothpastes are effective in reducing caries; the reductions are larger in those with more compared to less caries. Fluoride toothpaste may reduce inequalities and this will be explored further by assessing possible differences in effects across socioeconomic gradients from study level data available from the trials. We were unable to reach definite conclusions about adverse effects (especially fluorosis) that might result from the use of fluoride toothpaste, from data reported in the trials.