While you're worrying about lingering odors from garlic and onions, those germs could be making hydrogen sulfide, the same gas that gives rotten eggs their distinctive smell. It gets worse. Some germs release putrescine, another sulfurous compound that's the essence of rotting meat. And then there's cadaverine -- enough said.
FOR THE RECORD:
Bad breath: In Monday's Health section, an article about mouthwash referred to putrescine, an organic compound, as sulfurous. Putrescine, though malodorous, contains no sulfur. —
It's no wonder mouthwashes are such big business. Most mouthwashes rely on alcohol to kill germs by the bunches and strong scents to drown out any lingering odors. But a mouthwash called SmartMouth, previously sold under the less-catchy name of TriOral, takes a different approach.
SmartMouth, manufactured by St. Louis-based Triumph Pharmaceuticals, comes in two separate pump bottles. One bottle contains sodium chlorite, a cleansing agent that combines with sulfurous gases to blunt their smell. The other bottle contains zinc (in the form of zinc chloride), a mineral that discourages germs from releasing the gases in the first place. Users are instructed to mix four pumps of each bottle in a small cup and rinse for 30 to 60 seconds. Combining the two solutions creates a temporary burst of free zinc ions that are especially eager to attach to germs.
SmartMouth is sold in drugstores and grocery stores everywhere. Expect to pay about $10 for the two 8-ounce bottles. If you rinse twice a day as the instructions suggest, the bottles will last about 15 days.
The claims: According to the packaging, SmartMouth can "eliminate and prevent bad breath -- even morning breath -- for 24 hours" if used twice a day. The SmartMouth website claims that the product works "12 times longer than all other mouthwashes."
Susanne Cohen, a dentist and the chief executive and president of Triumph Pharmaceuticals, says rinsing with SmartMouth can freshen breath for 12 hours. "No other mouthwash has been shown to work for more than one hour."
The bottom line: The Healthy Skeptic doesn't have a huge problem with bad breath -- at least as far as he knows. Maybe everyone is just polite and forgiving. Anyway, he tried SmartMouth twice a day for several days. The package warns that the rinse might "create a brief dry sensation," a caveat that should be printed in bold 18-point type. Don't be surprised if your mouth suddenly feels like sandpaper with a hint of mint. The moisture returns in a half hour or so, and you'll be left with a clean feeling that does seem to last for hours.
A 2004 study published in the Journal of Clinical Dentistry suggests that SmartMouth can provide 12-hour protection against bad breath. (Triumph Pharmaceuticals funded the study, but Cohen says the company had no control over the findings.) Forty-eight volunteers with healthy mouths (no gingivitis, extensive cavities or obvious periodontal disease) rinsed with mouthwash twice daily. Some used a mouthwash with no active ingredients, some used a mouthwash with zinc chloride but without sodium chlorite and some used SmartMouth with zinc chloride and sodium chlorite.
Two weeks and four weeks later, researchers checked for sulfurous gases in each subject's breath. The subjects had been told to abstain from food, mouthwash and toothpaste for 12 hours before each test. Even though a half-day had passed since their last rinse, the SmartMouth users had much cleaner breath than anyone else. Because of this study, the Better Business Bureau ruled this year that the company had a "reasonable basis" for making the claim that SmartMouth works for up to 12 hours.
Still, SmartMouth hasn't exactly caused a sensation among experts in the field of bad breath. Christine Wu, chairwoman of the 2007 conference of the International Society for Breath Odor Research -- yes, such a society exists -- says she has never heard of SmartMouth. But she did say that mouthwashes containing zinc are generally effective enough to be in the same league as alcohol-based breath fresheners.
Susan Karabin, a Manhattan periodontist and the president of the American Academy of Periodontology, says mouthwashes can temporarily reduce bad breath. But to really combat the odors, she recommends going after the root of the problem. As Karabin explains, the germs that make foul-smelling gases find refuge in inflamed gums, the nooks and crannies on the tongue and underneath layers of plaque on the teeth.
"Flossing and brushing is the best thing you can do to remove bacteria and plaque," Karabin says. "You're not just eliminating the odor, you're eliminating the source."
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You can read more Healthy Skeptic columns at latimes.com/skeptic.