Don't put down that floss: Listerine rinse an "adjunct" to oral health

By Meg Nugent
Newhouse News Service

Rinsing the mouth can't replace proper flossing as a way to remove food debris caught in the tight spaces between teeth.

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It's incredible!

It's easy!

Clinical studies prove it!

These are a few of the messages you'll get from a recent commercial saying Listerine is as good as flossing when it comes to wresting germs that cause plaque and gingivitis from between your teeth.

"It's incredible news. And we just can't keep it bottled up. Listerine's as effective as floss," declares the male narrator as a big bottle of Cool Mint Listerine splashes its blue contents across the TV screen. "Clinical studies prove it. So, even if you don't floss like you should, now you can get its healthy benefits from simply rinsing. Listerine kills the germs that cause plaque, even between teeth." (Cut to cartoon river of Cool Mint Listerine flowing between a cartoon set of teeth.)

"So, it's as effective as floss and it's so-o easy," claims the narrator.

You may be so-o dazzled by the easiness of it all, not to mention those waves of blue mouthwash sloshing around, that you've overlooked two more, but comparatively less heralded, messages that appear in small black type toward the bottom of your TV screen, near the commercial's end:

"Floss daily," reads one.

"Ask your dentist," reads the other.

What about all this "as effective as" stuff?

Before you pop the cork and start celebrating the demise of your flossing regime — that is, if you have one — put on your time-to-be-an-educated-consumer cap.

The commercial is the result of Listerine going public with two clinical studies, sponsored by Pfizer Consumer Healthcare, the Morris Plains, N.J.-based maker of Listerine, that show a couple of 30-second rinses per day with the mouthwash is "at least as effective" as flossing once per day for reducing plaque and gingivitis between the teeth.

Following an extensive approval process from the American Dental Association, which required the six-month clinical studies, the ADA gave the nod to Pfizer to publicize the claim to consumers.

What about cavities?

Fine art of flossing Mystified about flossing? Here's the right way, from the American Dental Association: • Break off about 18 inches of floss and wind most of it around one of your middle fingers. • Wind the remaining floss around the middle finger of the opposite hand. This finger will take up the floss as it becomes dirty. Hold the floss tightly between your thumbs and forefingers. • Gently guide the floss between your teeth, using a gentle rubbing motion. Never snap the floss into the gums. • When the floss reaches the gum line, curve it into a C shape against one tooth. Gently slide it into the space between the gum and the tooth. • Hold the floss tightly against the tooth. Gently rub the side of the tooth, moving the floss away from the gum with up-and-down motions. • Repeat this method on the rest of your teeth. • Don't forget the back side of your last tooth. • People who have trouble handling dental floss may prefer to use another kind of interdental cleaner. These aids include special brushes, picks or sticks. If you use interdental cleaners, ask your dentist about how to use them properly, to avoid injuring your gums. Source: The American Dental Association

The ADA gave its approval with the caveat that the company needed to promote the importance of continuing to brush and floss every day, according to Clifford Whall, director of the ADA's Acceptance Program. The program oversees designations of the ADA's Seal of Acceptance you see on certain oral hygiene products such as dentifrice (aka toothpaste) and mouthwash.

"This was a key condition to the ADA permitting Pfizer to take the results of these studies to the public," says Whall.

Hence the little warning to "Floss daily" near the end of the television ad.

"This is a difficult message," says Whall. "Here are two studies saying rinsing is as effective as flossing, yet both Listerine's manufacturer and the ADA says you should continue to floss daily."

Pfizer needs to keep banging the drum for flossing and brushing, Whall says, because the two studies — published, respectively, in the March 2003 issue of the Journal of the American Dental Association (JADA) and the December 2002 issue of the American Journal of Dentistry — were limited in their scope.

Whall says both studies concentrated on a sampling of people with mild to moderate gingivitis and didn't examine the effect the mouthwash would have on those with more advanced gum disease, such as periodontitis. Whall also says plaque between teeth can lead to cavities but neither study examined whether Listerine had the same effect as flossing on reducing cavities between teeth.

Plus, floss has some special qualities not shared by a mouthwash.

"Flossing and interdental cleaners also help remove food debris caught between teeth that may not be rinsed away," according to the ADA.

The Listerine people readily agree.

"If you have spinach from lunch stuck in your left molar, Listerine is not going to get that out," says Faith Paris of Ketchum Associates, the public relations firm representing Pfizer. "Listerine is a great addition to your overall [oral care] routine," she adds, "because it will still reach those hard-to-reach areas."

An adjunct to flossing

While announcing the studies to the public, Pfizer also unveiled the results of a 2004 oral hygiene survey, sponsored by the company, in which approximately 90 percent of dentists said most patients don't floss daily.

The study published in JADA found Listerine used twice daily for 30 seconds each time reduced plaque between the teeth by 20 percent and gingivitis by 11 percent after six months, while flossing resulted, respectively, in 3.4 percent and 4.3 percent reductions. This study reinforced the findings of the study published in 2002. Pfizer financed both studies, which looked at a total of about 600 subjects ages 18-65 with mild to moderate gingivitis.

Pfizer attributes Listerine's effectiveness to four essential oils: thymol, eucalyptol, methyl salicylate and menthol.

The essential oils are effective, says Mike Lynch, director of clinical research for oral care at Pfizer, because they "wreak havoc" on the outer coating of the bacteria on the teeth, eventually killing the bacteria by punching holes through it.

"We also know Listerine penetrates the plaque. It will soak into the plaque around the gum area," he says.

Neither study said it was OK to stop flossing. Rather, both of them suggested Listerine could be a useful "adjunct" to such mechanical oral hygiene regimens as brushing and flossing.

Just to make things more interesting, a more recent study, published in the April 2004 JADA issue, showed people who brushed and flossed and used Listerine were able to reduce plaque and gingivitis even more than those who just brushed or who only brushed and flossed.

The Listerine-as-adjunct approach seems to be the one that's generally backed by dentists.

"It always has been a good adjunct. Listerine, used a couple of times a day, is definitely helpful," says Montclair, N.J., dentist Michael Medler. "But without the mechanical [action of flossing] to remove plaque from between the teeth, the Listerine can't get there."

Copyright © 2004 The Seattle Times Company

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