Chewing Gum Puts Clamp on Tooth-Decay Bacteria

CHICAGO -- Chewing gum containing xylitol, a sweetener with antimicrobial properties, temporarily suppresses bacteria that cause tooth decay, according to university researchers in a study published in the July issue of The Journal of the American Dental Association.

In the study, the gum was chewed after treatment with an antimicrobial mouthrinse, chlorhexidine, was stopped. The mouthrinse is used to reduce the bacteria (mutans streptococci) linked to increased risk for tooth decay. However, without further intervention the bacteria tend to quickly return to pretreatment levels.

"This study demonstrated that xylitol (made from the bark of birch trees) chewing gum can be used to extend the suppression of mutans streptococci," said authors Gary H. Hildebrandt, D.D.S., M.S., assistant professor, and Brandon S. Sparks, MS, research fellow. Both are from the School of Dentistry, University of Minnesota at Minneapolis.

In the study supported by a National Institutes of Health, National Institute of Dental and Craniofacial Research grant through the University of Minnesota Oral Health Clinical Research Center, the authors evaluated the effect of xylitol chewing gum on bacteria re-growth. Procter & Gamble supplied a portion of the mouthrinse used in the study.

The authors selected 151 subjects with elevated mutans streptococci levels. The subjects rinsed with chlorhexidine gluconate mouthrinse twice daily for two weeks and were randomly assigned to a test, placebo or control group.

In the test group of 51 people, they chewed xylitol gum three times daily after meals for a minimum of five minutes each time. The placebo group of 50 people chewed a commercial sorbitol-aspartame and saccharin-sweetened chewing gum three times daily after meals for a minimum of five minutes. The control group of 50 did not chew any gum. The study lasted three months.

"Use of xylitol chewing gum can retard return of oral bacteria after chlorhexidine treatment," the authors concluded after the three-month period. "Used in conjunction with other caries control strategies, such as diet modification, fluoride and sealants, a xylitol-sweetened chewing gum appears to be a helpful treatment for controlling tooth decay."

Results also showed that using chewing gum with a sorbitol-aspartame-saccharin sweetening mixture or not chewing any gum was ineffective in maintaining suppression of the tooth-decaying bacteria.

For more information about the American Dental Association's (ADA) position on this and other oral health issues, visit the ADA Web site at