CINCINNATI, Ohio -- Lead fears are popping up somewhere more startling than children's toys: your teeth.

Video: What's In Your Mouth?

The American Dental Association has launched a large investigation to find out how widespread the use of tainted bridges, crowns and fillings really is, Cincinnati television station WLWT reported.

In the meantime, however, the group warned patients to make sure they know what their dentist is putting in their mouths.

"If it saves a buck, yeah, you'll have a certain portion of the population that will try very hard to do it, whether it's safe or not," said Dr. Jane Mays, a Hyde Park dentist.

Last week, the ADA confirmed bridges, crowns and fillings put into people's mouths were testing positive for lead. The tainted crowns, which come from China, were seen as a way for U.S. dentists to cut costs.

"They probably pay one-sixth the cost for a Chinese crown than they would a domestic, American crown," said Mays.

She said it's the patients who could end up paying the price, because they're the ones fitted with dental work that can carry five times the amount of lead allowed in toys.

City and state dental groups have teamed with lawmakers to pass a bill that would regulate the use of lead in crowns and fillings in Ohio. And the ADA said it is now testing both foreign- and domestic-made crowns to determine if they release lead into the patients' mouths once they're put in.

In the meantime, doctors said not to take any chances.

"(Patients) need to have a very serious discussion with their dentist about, 'What's in my crown?" said Mays.

Officials warned that even crowns from American companies could contain lead because they often outsource their work to Chinese-based manufacturers.