Business Law

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Court Enjoins Listerine Advertising Campaign
Jeffrey S. Edelstein, Manatt, Phelps & Phillips, LLP, New York
E-mail: jedelstein@manatt.com

Introduction
The Listerine Advertising Campaign
The Listerine Studies
Literal and Implied Falsity
Public Health Risk


Introduction
A federal judge has ruled that an advertising campaign by Pfizer, claiming that the mouthwash Listerine is as effective as flossing in fighting tooth and gum decay, is false and misleading and poses a public health risk.

In the January 6, 2005 decision, Judge Chin of the United States District Court for the Southern District of New York issued a preliminary injunction, ordering Pfizer to stop running the ads. The lawsuit was brought by McNeil-PPC, Inc., a Johnson & Johnson company that is the market leader in dental floss.

The Listerine Advertising Campaign
Print ads and hang tags featured a Listerine bottle balanced on a scale against a floss container, with the words: "Listerine antiseptic is clinically proven to be as effective as floss at reducing plaque and gingivitis between the teeth." The campaign also featured a television commercial named the "Big Bang," claiming that "Listerine’s as effective as floss at fighting plaque and gingivitis. Clinical studies prove it." The commercial cautioned that "There’s no replacement for flossing," but stated that "if you don’t floss like you should, you can get its plaque-fighting benefits by rinsing." The commercial showed a narrow stream of blue liquid flowing out of a Listerine bottle, then tracking a piece of dental floss being pulled from a floss container, and then swirling around and between the teeth, which Judge Chin said brought to mind "an image of liquid floss."

The Listerine Studies
Pfizer based its claims on two clinical studies which it sponsored involving Listerine and floss. These studies compared the efficacy of Listerine against floss in controlling plaque and gingivitis in subjects with mild to moderate gingivitis. They concluded that Listerine was at least as good. However, Judge Chin found that they did not provide adequate support for the proposition that "Listerine is as effective as floss against plaque and gingivitis." First, the studies excluded individuals with severe gingivitis or with any degree of periodontitis (inflammation that develops in deep tissues and is a major cause of tooth loss), and they did not purport to draw any conclusions with respect to these individuals. Hence, in Judge Chin’s opinion, "the literal claim in Pfizer’s advertisements is overly broad, for the studies did not purport to prove that Listerine is as effective as floss "against plaque and gingivitis," but only "against plaque and gingivitis in individuals with mild to moderate gingivitis."

Second, according to Judge Chin, the 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, even in individuals with mild to moderate gingivitis. The two studies only showed that Listerine is as effective as floss when flossing is not done properly. The authors of both studies recognized that the plaque reductions in the flossing groups were lower than expected, and hypothesized that "behavioral or technical causes were the reasons."

Literal and Implied Falsity
Judge Chin found that the ads for Listerine were both explicitly and implicitly false. They made the explicit claim that "clinical studies prove that Listerine is as effective as floss against plaque and gingivitis." Since the claim relied on clinical studies, it is an "establishment claim," and under the case law the plaintiff need only prove that the studies referred to "were not sufficiently reliable to permit one to conclude with reasonable certainty that they established the proposition for which they were cited." For the reasons discussed above, the judge concluded that they were not sufficiently reliable.

Judge Chin also found that the ads sent the implicit message that Listerine is a replacement for floss—that the benefits of flossing may be obtained by rinsing with Listerine, and that those consumers who do not have the time or desire to floss can switch to Listerine instead. He found that the words and images used in the ads confirmed that this message was being sent. In addition, he found that a consumer perception study showed that a substantial percentage of consumers who saw the ads took away the message that "you can replace floss with Listerine." Judge Chin found this implicit message to be false as well.

"Dentists and hygienists have been telling their patients for decades to floss daily," Judge Chin wrote. "They have been doing so for good reason. The benefits of flossing are real—they are not a ‘myth.’ Pfizer’s implicit message that Listerine can replace floss is false and misleading." Judge Chin wrote that flossing provides certain benefits that Listerine does not. Floss penetrates subgingivally to remove plaque and biofilm below the gumline. Flossing, as part of a regular oral prevention program, also can reduce periodontitis. Flossing reduces tooth decay and cavities. Flossing also removes food debris between the teeth, including pieces of food trapped between the teeth that rinsing cannot dislodge.

The judge also noted that the authors of articles regarding the studies on which Pfizer based its ad campaign had emphasized that dental professionals should continue to recommend daily flossing and cautioned that they were not suggesting that mouth rinse be used instead of floss.

Public Health Risk
Finally, Judge Chin found that the Listerine campaign posed a public health danger. He concluded that "Pfizer’s false and misleading advertising also poses a public health risk, as the advertisements present a danger of undermining the efforts of dental professionals—and the ADA—to convince consumers to floss on a daily basis."

 

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