Fillings are great for fixing cavities, but certain types might lead to surprising problems in kids.

More than half of American children have had a cavity by age 7. These days, kids are getting fillings from a tooth-colored composite, instead of silver-mercury fillings.

A chemical called BPA, which has been linked to healthcare concerns, is sometimes used to make the composite fillings.

In a new study published in the journal Pediatrics, researchers collected treatment data from 534 children seen at several community dental clinics. The children were all 6-10 years old at the start of the 5 year trial.

Psychological assessments were made at the beginning and completion. The findings: Composite fillings that contained the material related to BPA were linked to anxiety, depression, social stress and other problems. These issues weren't linked to mercury fillings.

The next time a cavity strikes your child, talk to your dentist about the benefits and possible concerns that may come with different types of fillings.