Abstract: In this review, we included 37 trials involving 15,813 children and adolescents. All trials tested supervised use of fluoride mouthrinse in schools, with two studies also including home use. Almost all children received a fluoride rinse formulated with sodium fluoride (NaF), mostly on either a daily or weekly/fortnightly basis and at two main strengths, 230 or 900 ppm F, respectively. Most studies (28) were at high risk of bias, and nine were at unclear risk of bias. From the 35 trials (15,305 participants) that contributed data on permanent tooth surface for meta-analysis, the D(M)FS pooled PF was 27% (95% confidence interval (CI), 23% to 30%; I2 = 42%) (moderate quality evidence). We found no significant association between estimates of D(M)FS prevented fractions and baseline caries severity, background exposure to fluorides, rinsing frequency or fluoride concentration in metaregression analyses. A funnel plot of the 35 studies in the D(M)FS PF meta-analysis indicated no relationship between prevented fraction and study precision (no evidence of reporting bias). The pooled estimate of D(M)FT PF was 23% (95% CI, 18% to 29%; I² = 54%), from the 13 trials that contributed data for the permanent teeth meta-analysis (moderate quality evidence). We found limited information concerning possible adverse effects or acceptability of the treatment regimen in the included trials. Three trials incompletely reported data on tooth staining, and one trial incompletely reported information on mucosal irritation/allergic reaction. None of the trials reported on acute adverse symptoms during treatment. This review found that supervised regular use of fluoride mouthrinse by children and adolescents is associated with a large reduction in caries increment in permanent teeth. We are moderately certain of the size of the effect. Most of the evidence evaluated use of fluoride mouthrinse supervised in a school setting, but the findings may be applicable to children in other settings with supervised or unsupervised rinsing, although the size of the caries-preventive effect is less clear. Any future research on fluoride mouthrinses should focus on head-to-head comparisons between different fluoride rinse features or fluoride rinses against other preventive strategies, and should evaluate adverse effects and acceptability.

Plain-language summary: We included 37 studies in which more than 15,000 children (aged six to 14 years) were treated with fluoride mouthrinse or placebo (a mouthrinse with no active ingredient) or received no treatment. All studies assessed supervised use of fluoride mouthrinse in school settings, with two studies also including home use. Most children received a sodium fluoride (NaF) solution, given at 230 parts per million of fluoride (ppm F) daily or a higher concentration of 900 ppm F weekly or fortnightly. Studies lasted from two to three years. Reports were published between 1965 and 2005, and studies took place in several countries. This review update confirmed that supervised regular use of fluoride mouthrinse can reduce tooth decay in children and adolescents. Combined results of 35 trials showed that, on average, there is a 27% reduction in decayed, missing and filled tooth surfaces in permanent teeth with fluoride mouthrinse compared with placebo or no mouthrinse. This benefit is likely to be present even if children use fluoride toothpaste or live in water-fluoridated areas. Combined results of 13 trials found an average 23% reduction in decayed, missing and filled teeth (rather than tooth surfaces) in permanent teeth with fluoride mouthrinse compared with placebo or no mouthrinse. No trials have looked at the effect of fluoride rinse on baby teeth. We found little information about unwanted side effects or about how well children were able to cope with the use of mouthrinses. Regular use of fluoride mouthrinse under supervision results in a large reduction in tooth decay in children's permanent teeth. We found little information about potential adverse effects and acceptability. Available evidence for permanent teeth is of moderate quality. This means we are moderately confident in the size of the effect. Very little evidence is available to assess adverse effects.