How can elementary schools save nearly $50 per student? By bringing in dental professionals to put sealants on their molars, federal health officials said Tuesday.

If that doesn’t sound like an education-related problem, consider this: Cavities that go untreated cause kids to do worse in school.

A study in the American Journal of Public Health found that students whose oral health was rated “good, fair or poor” were about three times more likely to miss school because of dental pain compared with kids with “very good or excellent” oral health. What’s more, kids who stayed home with toothaches were nearly twice as likely as their peers to earn mostly C’s, D’s and F’s in school.

Cavities are a risk for all kids, regardless of income level. Dr. Tom Frieden, director of the Centers for Disease Control and Prevention, called cavities “one of the most common chronic conditions among kids in this country.”

Molars are particularly vulnerable; these teeth do most of the chewing and are the most difficult to reach and clean. Indeed, nearly 90 percent of cavities are found on molars, experts say.

Sealants can reduce the risk of cavities by 81 percent over two years and keep fighting cavities for up to nine years, according to the Community Preventive Services Task Force, part of the U.S. Department of Health and Human Services. These plastic coatings cover the pits on top of molars, creating a barrier between the tooth and the bacteria that cause tooth decay.

You can think of sealants as a vaccine for teeth, Frieden explained.

“It’s a way of preventing cavities,” he said.

It would also save nearly $300 million in dental treatment costs, Frieden said.