A Replacement for Floss? Not so fast…

I wrote this blog in response to a wonderful, controversial subject brought up in a comment from Patrick.

Recently (2004), Listerine aired a commercial claiming that rinsing your mouth two times a day for 30 seconds with their mouth wash is comparable to flossing daily. This claim was backed with research conducted by an independent research firm, in contract with the company Pfizer. Pfizer funded this research project and manufactures Listerine.

The study was published in the Journal of the American Dental Association (JADA). Medical News Today summarizes the results:

"Listerine Antiseptic reduced plaque between the teeth by 20 percent and gingivitis by 11 percent, while flossing led to 3.4 percent and 4.3 percent reductions respectively. This trial reinforces the findings of a prior study published in the American Journal of Dentistry (AJD)."

These results are something to consider, but one cannot stop here. The American Dental Association (ADA) published these results and gave their seal of approval to Listerine on the condition that Listerine must promote both brushing and flossing. The ADA never concluded that rinsing could replace flossing, only that it had the possibility to be as good as flossing.

The controversy arouse when Listerine’s commercial informing the public of these finding was aired. The commercial only had in small print across the bottom, “floss daily” and “ask your dentist”. The overall commercial however gave the impression that rinsing could completely replace flossing. It was deceiving to the uninformed public.

Judge Chin became active on the case when a company of Johnson & Johnson, a leading manufacturer of dental floss, sued Pfizer. Judge Chin ruled that the commercial did not clearly relay that “Listerine is as effective as floss against plaque and gingivitis.” He also noted that the study only proved their point to be true in people with mild cases of plaque and gingivitis. The study did not incorporate people with advanced levels of gingivitis or gum disease. Thus, Judge Chin ruled Listerine to remove the commercial from the air because they were falsely informing the consumer.

Many dentists were outraged with Pfizer’s claim as well. Dr. Chris Smiley of Smiley Family Dentistry wonderfully explains why rinsing cannot replace flossing.

"A rinse can flush off things on the tooth surface, but it will only penetrate a couple of millimeters into the gum line. Floss goes along the root’s surface and scrapes off that debris. No matter how hard you swish, you can’t blow some of that stuff off."

This is very important to note, in my opinion. If you think about what flossing is actually doing, which follows how Dr. Smiley describes, a simple liquid could not have the same benefits. (It seems difficult to me to believe that a liquid could clean your mouth well enough to add six years to your life!)

The conclusion that many dentists share, now that Listerine has changed its ad, is that adding rinsing to your daily oral care practices of brushing and flossing is a smart idea, but by no means can it replace the age-old preaching of floss.