There's a quick and easy way to prevent 80 percent of cavities, but most kids don't get it, federal health officials said Tuesday.
The treatment, dental sealants, works well, but only 60 percent of kids who need sealants get them, the Centers for Disease Control and Prevention says.
One good solution: doing it at school. But states often lack the funding to pay for such programs, and often bureaucratic requirements about having dentists on site can hold them up, also, the CDC said.
"Many children with untreated cavities will have difficulty eating, speaking, and learning," said CDC director Dr. Tom Frieden.
"Dental sealants can be an effective and inexpensive way to prevent cavities, yet only one in three low-income children currently receive them. School-based sealant programs are an effective way to get sealants to children."
The CDC says that 20 percent of kids and teenagers have untreated dental decay by the time they are 19. Kids with constant toothaches cannot eat properly and have trouble paying attention at school.
Related: Do Kids Need Dental Sealants?
Even though they are endorsed by the CDC and the American Dental Association, only 43 percent of 6- to 11-year-old children have a dental sealant, federal surveys show.
"Low-income children were 20 percent less likely to have sealants than higher-income children," the CDC's Susan Griffin and colleagues wrote in a report released Tuesday.
"School-age children without sealants have almost three times more cavities than children with sealants," the CDC added.
"Applying sealants in school-based programs to the nearly 7 million low-income children who don't have them could save up to $300 million in dental treatment costs."
That's because a filling costs more. In addition, once a tooth has been drilled to put in a filling, it's never as stable again.
But many states struggle to pay for such programs, the CDC team found.
"Federal funding of state oral health programs is largely competitive and varies widely by state," they wrote. "Many state and local school-based sealant programs cover part of their expenses by Medicaid billing."
And Medicaid, the joint state-federal health insurance plan for children and low-income people, is already badly stretched in most states.
One big expense is paying a dentist to oversee the program, the CDC found. One solution: Allow lower-paid professionals to administer sealant programs. At least one state has already done so.
"For example, in South Carolina, school-based sealant programs managed and staffed by dental hygienists deliver sealants in approximately 40 percent of high-need schools," Griffin and colleagues wrote.
"CDC currently provides funding to 21 state public health departments to coordinate and implement school-based and school-linked sealant programs that target low-income children and those who live in rural settings," the agency added.
It said the federal government plans to do more. It will classify pediatric dental services as an essential health benefit to be covered by dental insurance as part of the Affordable Care Act, for instance, and match state Medicaid and CHIP costs for sealants.
The sealants are plastic-based coatings that get into the cracks and crannies of molar teeth, stopping food and bacteria from starting the chemical reaction that leads to cavities.
Studies show they are safe and stop tooth decay, even when they are layered over an existing pre-cavity.
"Studies on sealant effectiveness indicate that sealants delivered in clinical or school settings prevent about 81 percent of decay at two years after placement, 50 percent at four years, and can continue to be effective for up to nine years through adolescence," the CDC said.
The American Dental Association (ADA) agrees, and says many people don't know that dental insurance often pays for them.
"Dental sealants are one-third the cost of a filling, so their use can save patients, families, and states money," the Pew Charitable Trusts, an independent, public service-oriented nonprofit, says in a statement. "Sealant programs based in schools are an optimal way to reach children — especially low-income children who have trouble accessing dental care."
One worry that parents may have is about BPA, a chemical found in the sealants that is increasingly linked with health risks. The ADA says the benefits of sealants far outweigh any perceived risk.
"The potential amount of BPA patients could be exposed to when receiving sealants is minuscule, and it's less than the amount a person receives from breathing air or handling a receipt," the ADA says.