http://www.usatoday.com/news/health/200 ... eath_N.htm
The primary ingredient in this newer class of mouthwashes with clinical-sounding names such as TheraBreath, Oxyfresh, CloSYS and ProFresh is sodium chlorite, also known as stabilized chlorine dioxide, sometimes used as a water purifier. These rinses claim to freshen breath for up to six hours. But one independent study found that several different sodium chlorite rinses worked for anywhere from four to 42 minutes.
These products change the chemical composition of odiferous gases so they no longer smell, but underlying bacteria remain potent and continue producing odors, Cohen says.
SmartMouth uses sodium chlorite, but in a new twist, it must be mixed with zinc chloride just before use. The zinc ions find the bacteria that produce rancid gases after eating amino acids, then block the amino-acid receptor sites so the bacteria cannot produce gas, Cohen says. After the bacteria die in around 12 hours, they are replaced by new bacteria. Again, it's time to rinse.
The National Advertising Division of the Council of Better Business Bureaus recently announced that a review of dental literature substantiated SmartMouth's claim that it prevents bad breath 12 times longer than any other mouthwash.
Another brand, Biotene, with its mouthwashes that combat dry mouth, takes a different approach. Its new PBF, or plaque-biofilm dissolving mouthwash, contains two enzymes that break down the biofilm and put the mouth bacteria into a healthy balance, says Michael Pellico, a Biotene chemist.
There's promising research on yet another liquid — a combination of zinc and chlorhexidine.
'Equivocal' results
Still, without reliable comparative testing, it is hard to know what works well, Lenton says. "People will tell you they have data, but then you see it" and find flawed methodology, she says. A report on oral malodor by the ADA found that results of most studies are "equivocal and proprietary."
The ADA's Whall stands by the report. Though the companies claim to have studies showing their mouth products are effective, "we can't verify" those claims, Whall says.
Even with the most effective products, however, some people practice such bad oral hygiene that nothing will help.
"There is still a lot of work to be done on bad breath," says Harold Katz, the California dentist who developed TheraBreath products.
