CHICAGO (CBS) — When you turn on the tap, it’s not just water that comes out. So does fluoride, to protect your children’s teeth.

But it may be having the opposite effect, CBS 2’s Susanna Song reports.

Your drinking water contains a tiny portion of fluoride, a mineral that has been shown for years to reduce tooth decay and cavities in children. But now a government study too much fluoride can create splotchy teeth, a condition called “fluorosis.”

Phil Finkel, a dentist at Illinois Center Dental in downtown Chicago, showed CBS 2 the extreme cases in which teeth are blemished with brown spots. But he argues there’s not enough fluoride in our drinking water to cause such problems.

“The benefits outweigh any risks,” he said.

Chicago’s tap water contains 0.9 to 1.05 mg of fluoride per liter of water. The federal standard since 1962 has been a range of 0.7 to 1.2 mg. The new recommendation is to set the level at the lowest amount that does the job: 0.7.

“When you ingest the water and ingest the fluoride as the teeth are developing, that’s how the fluoride gets into the enamel of the teeth, into developing teeth,” Finkel said.

For the Lifka family of Naperville, the change is especially important because their three boys have teeth that are still growing. They love to drink water.

“I hope their teeth are good for many years — one less thing to cover for costs,” dad Phillip Lifka says.

It’s important to watch your children between birth and 8 years old because that’s when their teeth are developing. How much fluoride they consume will determine if they get fluorosis later on in life.

Older kids and adults don’t have to worry.

It’s the first change in fluoride-level recommendations in nearly 50 years.

Contributing: AP

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