Keep your chompers healthy and sparkling with regular brushing… and perhaps fluoride. (For Spectrum Health Beat)

It’s been credited with transforming modern dental health, yet most of us have never seen it, touched it or even tasted it.

This invisible wonder is called fluoride, yet today some wonder if there’s such a thing as too much of a good thing.

We consulted a local expert, Bill Bush, MD, pediatrician-in-chief at Spectrum Health Helen DeVos Children’s Hospital, to offer four key facts about fluoride:

FACT 1: Fluoride helps fight cavities

Seventy years ago, Grand Rapids, Michigan, became the first community in the U.S. to fluoridate its water supply, designed to prevent tooth decay among its citizenry. By the mid-1960s, cities everywhere started adding the ingredient to their drinking supplies.

The results of fluoridation were hard to argue with, Dr. Bush noted.

“If you go back generations, think about how horrible people’s teeth were,” Dr. Bush said. “It’s because we didn’t supplement fluoride. In some areas, everybody at school would get varnish painted on their teeth to protect them. Now, most of your cities’ water supplies are supplemented with it, and we don’t have to do that. But that’s what they used to do. Kids would line up to get their teeth varnished in school.”

Like that old-fashioned varnish, fluoride covers the teeth underneath with a protective coating.

“Fluoride’s necessary because it keeps plaque from being able to build up on teeth,” Dr. Bush explained. “I always describe it to families as the shield on your tooth, keeping it from getting decayed.”

FACT 2: Fluoridation is recommended by experts

Dr. Bush isn’t alone in his appreciation of fluoride’s place in dental health.

The American Academy of Pediatrics and the American Dental Association agree that fluoride is effective in preventing tooth decay in children and adults. The dental association touts fluoridation as having “dramatically improved the oral health of tens of millions of Americans,” since Grand Rapids started the trend in ’45.

“Community water fluoridation is the single most effective public health measure to prevent tooth decay,” the association noted in its literature.

The Centers for Disease Control and Prevention and the Department of Health and Human Services also recommend fluoridation–within appropriate levels. Because of the addition of fluoride to many toothpastes, as well as in food we buy, the agencies are recommending levels of 0.7 parts per million of fluoride in drinking water.

FACT 3: Fluoride is found naturally in our water

Whether it is added to it or not, a little bit of fluoride is natural in our water. According the City of Grand Rapids website, Grand Rapids’ water source from Lake Michigan has a natural fluoride level that generally varies from 0.1 to 0.2 parts per million. Fluoride is added in the treatment process to bring the level up to 0.7 parts per million.

According to the CDC, some 10 million Americans drink water with naturally occurring fluoride at or above recommended levels. As a result, agencies have amended their advice on fluoride a bit.

“The American Academy of Pediatrics and the American Dental Association have changed the recommendation,” Dr. Bush said. “In the past, every young person that wasn’t on city water, we gave them recommendations to take fluoride supplements. Now we just ask where they’re getting their fluoride from.

“Especially kids, they get fluoride from daycare, and grandma’s house, and their toothpaste, too. If you go to the store, or the restaurant, daycare, church, or school, most likely the water is fluoridated.”

FACT 4: There are side effects from too much fluoride

“The reason why we’ve decreased the amount of supplemental fluoride is if you get too much you get fluorosis,” Dr. Bush said. “Fluorosis causes white streaks on the teeth. Most of that’s reversible, and mostly it’s on baby teeth. Other than fluorosis, I’m not worried about anything else. It’s just not a chemical that causes toxic effects.”