Investigator Stuart Saunders writes:
Compare these two news items about Listerine mouthwash.
1. “Listerine antiseptic as effective as dental floss” is the headline on a June 14, 2004 article in Medical News Today. The article says that
A long-term study published in the Journal of the American Dental Association (JADA) demonstrates that rinsing twice daily with Listerine? Antiseptic mouthrinse is as effective at reducing plaque and gingivitis in areas between the teeth as flossing once daily.’ … This trial reinforces the findings of a prior study published in the American Journal of Dentistry (AJD).
2. That claim — that Listerine is as effective as dental floss — was used in advertising for the product for some time before Judge Denny Chin of NY ordered it not used as it was obviously not correct. The judge’s ruling was reported in the January 10, 2005 issue of Law.com:
Chin found that Pfizer’s claims were not just implicitly false or misleading but literally false. He said the clinical studies “were not sufficiently reliable to permit one to conclude with reasonable certainty that Listerine is as effective as floss in fighting plaque and gingivitis,” ruled Chin. “What the two studies showed was that Listerine is as effective as floss when flossing is not done properly.”