Fluoride takes a bite out of cavities

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Fluoride takes a bite out of cavities
January 14, 2008
By Cynthia Billhartz Gregorian
STLToday.com

Braces, teeth whiteners, porcelain veneers. Those are all fine and dandy. But when it comes to basic tooth health, let's not forget good old-fashioned brushing and flossing, nutrition and fluoride. Especially the latter.

Fluoride protects teeth by killing bacteria and hardening enamel so acids cannot dissolve teeth.

Dentists are seeing an upswing in the number of cavities in recent years, and they attribute it to two things: too many sugary drinks and not enough fluoride.

Dr. Poonam Jain laments the popularity of bottled water and even filters on faucets. Advertisement

"We went through all this trouble and taxpayer money to put fluoride into community water only to have people remove it or drink bottled water," says Poonam, director of community dentistry and associate professor at SIU School of Dental Medicine in Alton.

"Because this (bottled water) phenomenon is relatively new, I haven't found any published literature on an increase in cavities, except in toddlers," she says. "And so far that hasn't been linked to bottled water as much as it is to sugared fluid in bottles and sippy cups. But over time, dentists are afraid we are going to see an increase in cavities because a lot of bottled waters don't include recommended amounts of fluoride."

Studies in the 1940s and '50s determined that the ratio of fluoride to water needed to be between 0.7 and 1.2 parts per million to effectively reduce cavities. And as soon as communities started adding that recommended amount to their water supplies, cavities plummeted up to 70 percent.

Jain and her students at the SIU School of Dental Medicine recently tested Aquafina, Dasani, Ice Mountain and Great Value brand bottled waters and found that none had enough fluoride to meet the requirements for preventing decay.

Fluoride in high doses can be toxic. It can cause tooth enamel to chip and become brown and mottled. Some people worry about this. But Jain points out how we've safely ingested the recommended quantities in tap water for several decades now.

In general physicians recommend drinking four to five 8-ounce cups of unfiltered tap water a day, Jain says. Dentists recommend also drinking milk and avoiding sugary beverages.

Jain says people between the ages of 40 and 45 are unique because they're among the oldest patients without cavities. She attributes it to the fluoride in tap water as well as the first public messages 20 and 30 years ago about brushing, flossing and avoiding sugary drinks.

Since then, a lot people seem to have misinterpreted the health benefits of bottled water and even fruit juices.

"There's no fruit in it," Jain says. "Most of it's water, sugar and color dye. That concerns me greatly. It's much better to eat an apple or orange."

Applying acrylic sealants to children's permanent molars as soon as they erupt in the mouth also goes a long way toward preventing decay, she says. Sealants prevent cavities on fissured surfaces while fluoride prevents them on smooth surfaces.

They don't take the place of each other, but they do complement each other, Jain says.

And adults who think they no longer need fluoride better think again. As we age, we lose gum tissue, exposing the roots of our teeth.

"Fluoride is needed to protect those root surfaces. I have a 69-year-old patient who has a cavity on every single tooth in his mouth and all the roots are decayed," Jain says, adding that treatments for older patients include teeth trays filled with fluoride and applications of fluoride varnishes.