For Maryland dentist Ricardo Perez, flouride in the water has helped fight tooth decay and left patient's with pearly whites.

But in recent years, he and other dentists have noticed extra white spots like these, called fluorosis, from too much fluoride making subtle but increased appearances.

Dr. Perez says �perhaps there is a little of too much fluride happening and seeing some of side effects on children's teeth.�

According to the CDC, 23% of kids 12 to 15 had signs of fluorosis in a 1986 and 1987 study. But by the early 2000's, 41% of kids did. In extreme cases, teeth can even get pitted.

So the federal goverment today announced plans to lower the recommended levels of fluoride in water supplies.

Dr. Howard Koh, the U.S. Health and Human Services Assistant Secretary for Health says �nowadays, people receive fluoride from several sources in addition to drinking water, such as toothpaste and mouth rinses.�

Fluoride has been added to many public water supplies since the 1940's. It's up to states and cities to decide whether to add it and some have fought against the addition in places like Wichita and Portland.

But for the American Dental Association and dentists like Dr. Perez, low amounts of fluoride are considered safe, and necessary. And new government recommendations for finding the right fluoride level. Something to smile about.