New fluoride varnish value study questions

Fluoride varnish has become a popular anti-cavity treatment for children, and it’s not hard to see why. It is relatively easy to implement, and not just for dentists or dental hygienists. Pediatricians can do it too, with minimal guidance. The sticky varnish goes on with a brush and then dries in a few hours. There is little risk of children ingesting the fluoride, as they might with other topical treatments such as gels.

It’s not very expensive either, with treatment costs generally ranging from about $25 to $55. This does not seem to be a prohibitive price to pay to protect a child from tooth decay.

But a new study by two University of Washington researchers and their colleagues questions the cost-effectiveness of fluoride varnish for preschoolers and calls its anti-cavity effects “modest and uncertain” in this age group.

Dr. Joana Cunha-Cruz and Dr. Philippe Hujoel of the UW School of Dentistry and four research colleagues reached their conclusion after reviewing 20 clinical trials of fluoride varnish in 13 countries. They looked at trials in which fluoride varnish was used alone or in an oral health program and also tested the effects of using fluoride varnish compared to placebo, usual care or no treatment.

“As much as we want fluoride varnish to be effective, the current evidence does not support a huge benefit for its use in young children,” said Dr. Cunha-Cruz.

In their new study, which was recently published in the journal Dental caries research, she and her colleagues noted that fluoride varnish applications specifically target children at high risk of tooth decay, or tooth decay. It is not considered a primary form of treatment, but rather an adjunct to other fluoride treatments such as toothpaste or fluoridated water.

However, the researchers reported that more recent clinical trials in both low- and high-risk groups “failed to show a protective effect of fluoride varnish applications.”

“Cost-effectiveness analyzes are needed to assess whether fluoride varnish should be adopted or abandoned by dental services,” they said in their study.

The researchers aren’t arguing that fluoride varnish doesn’t work. Their analysis showed that the risk of developing new cavities was reduced by 12 percent among children who received fluoride varnish, compared to those who did not. And they added that fluoride varnish could still be a cost-effective alternative in some cases. However, they also stated, “This was a rather modest benefit, as a large number of children developed new dentin caries lesions regardless of fluoride varnish use.”

Fluoride concentrations can also vary between different varnishes, Dr. Cunha-Cruz said.

This is not to say that there aren’t highly effective alternative topical treatments. Sealants do a good job of protecting teeth, especially those hard-to-reach in the back of the mouth, Dr. Cunha-Cruz said. Even better are glass ionomer sealants, which release fluoride, as opposed to resin-based sealants, which do not.

Sealants are more difficult to apply than varnish, but Dr. Cunha-Cruz said they remain effective for two to three years. Silver diamine fluoride has also grown in popularity and is very effective at stopping tooth decay, he said, but more research is needed into its preventive effect. It can also discolor teeth, but this is less of a concern for preschoolers who haven’t yet lost their primary teeth.

“Evidence continues to support the use of fluoride toothpaste, which is easy and low-cost,” said Dr. Cunha-Cruz. “The value of toothpaste is how it creates a daily presence of fluoride in the mouth.” A fluoride rinse is also effective in this way, he said.

For now, she and her researchers are calling for more studies on the cost-effectiveness of fluoride varnish among different populations and application settings. She suggests caregivers discuss the pros, cons and alternatives to fluoride varnish for tooth decay prevention with a child’s dentist.

Meanwhile, in addition to using fluoride toothpaste and brushing every day, Dr. Cunha-Cruz suggests another approach: “Reducing your sugar intake is an even more cost-effective strategy.”