Kids who come from low-income families – or who live in rural areas – are more likely to get cavities. That's according to a study done by the Minnesota Department of Health.
The survey took a look at third-graders in public schools.
It found that kids in schools that serve mostly higher-income families have better access to cavity-preventing dental sealants – plastic material applied to back teeth to prevent decay – and have fewer cavities.
Meanwhile, third-graders in schools that serve mostly lower-income families were 1.6 times more likely to have tooth decay.
The study used the number of kids eligible for free or reduced-price lunches to determine what percentage of students were living in lower-income households.
And the department compared information from schools where 25 percent or fewer students were on the program with schools that had more than 75 percent on meal assistance programs.
Comparing kids in rural and urban schools, the rural third-graders were 1.3 times more likely to have tooth decay.
Having access to fewer dental professionals may be part of the reason why rural kids had more cavities, the Rural Health Information Hub says.
As far as oral health goes, Minnesota's kids are doing well compared to those from other states.
In 2015, 50 percent of third-graders in Minnesota had at least one cavity. The national median is 55 percent.
Additionally, 60 percent of third-graders in Minnesota have sealants. The U.S. median is 44 percent.
The Centers for Disease Control and Prevention says sealants are typically applied to kids' molars, which are rough, to keep germs and food from getting into grooves and causing decay. They can last up to 10 years.