Clinical Question

Are topically applied fluoride varnishes safe and effective in preventing dental caries in children and adolescents?

Evidence-Based Answer

Topically applied fluoride varnishes are safe and effective in preventing dental caries in children and adolescents. There is little information about adverse effects or treatment acceptability. Family physicians should consider incorporating fluoride varnish into childhood preventive care visits. (Strength of Recommendation: A, based on moderate-quality evidence with significant heterogeneity.)

Practice Pointers

A significant health problem among children is dental caries; 20% of children five to 11 years of age have untreated dental caries, and 39% have had dental restoration.¹ Only 42% of all persons older than 24 months visited a dentist in 2011.² Fluoride varnish is inexpensive (approximately $1 per application) and can be applied easily to teeth by physicians to prevent decay. This updated Cochrane review was originally published in 2002 based on seven trials.

The authors reviewed 22 trials that included 12,455 patients 16 years or younger. Patients were treated with fluoride varnish two to four times per year vs. either placebo gel or no treatment. Study duration was one to five years. The primary outcome measured was the number of decayed, missing/extracted, and filled (DMF) permanent or primary tooth surfaces. The incidence of DMF surfaces in the control group vs. the treatment group was analyzed and used to calculate a prevented fraction percentage. Thirteen trials looked at children and adolescents with permanent teeth. Pooled data showed that patients treated with varnish experienced a 43% reduction in DMF tooth surfaces (95% confidence interval [CI], 30% to 57%; P < .0001). Ten studies that analyzed the effect on primary teeth demonstrated a 37% reduction in DMF surfaces in those treated with fluoride varnish (95% CI, 24% to 51%; P < .0001). All studies showed a benefit of fluoride varnish in caries prevention.

The authors also reviewed whether the effectiveness of fluoride varnish was influenced by initial caries severity, background exposure to fluoride (e.g., water), concentration of fluoride varnish, frequency of applications, and whether a professional dental cleaning was provided before varnish application. There was no variation in prevented fraction percentage based on these factors; however, only a few trials reported these data.

The evidence was assessed to be of moderate quality rather than high quality because many of the studies were noted to have an unclear or high risk of bias in at least one of eight bias domains. No adverse effects were noted.

In 2014, the U.S. Preventive Services Task Force gave a grade B recommendation to the following statement: Apply fluoride varnish periodically to the primary teeth of all children starting at primary tooth eruption through age five years.³ This review supports that recommendation and suggests that the benefit of fluoride application may exist beyond five years of age. Medicaid currently reimburses physicians in 49 states (all but Indiana) for the service; all insurances under the Affordable Care Act must cover the service for patients until six years of age.⁴