WASHINGTON - No scientific proof of effectiveness exists for about 80 percent of the most widely used ingredients in anti-plaque toothpastes and mouth rinses, a Food and Drug Administration advisory panel has found.
Among them are two icons of oral health - baking soda and hydrogen peroxide - which have gained popular renown for their supposed ability to combat dental plaque and gingivitis.
FDA, which began reviewing the products in the 1990s, is publishing the results today. It will begin a process that could lead to new labels and toned-down advertising claims on scores of products that use the ingredients.
After considering industry and other comments on the 219-page document, the FDA will decide which ingredients can be legally marketed as effective against plaque and gingivitis.
Until then, the findings are not official FDA policy, Robert L. Sherman, of the agency's nonprescription drug staff, said in an interview.
“These are basically opinions of the advisory panel,” Mr. Sherman said. “The FDA may eventually agree with them, disagree with them, or make entirely different findings.”
Such toothpastes and mouth rinses have been booming in popularity with greater public understanding that gum disease - not decay - is the leading cause of tooth loss in adults.
Dental plaque is the sticky film of food debris and bacteria that often underpins gum, or periodontal, disease. If not removed regularly with brushing, flossing, and professional care, plaque can lead to gingivitis, an early stage of periodontal disease that involves redness, bleeding, and inflammation of the gums.
Since those tough, pink tissues hold teeth firmly in the jaw, the result often is tooth loss, as diseased gums recede and develop pockets of infection.
The review was done by an expert scientific panel, which heard testimony and waded through thousands of pages of clinical trials and other studies, looking for evidence that anti-plaque ingredients actually do work and are safe.
Dr. Robert J. Genco, a periodontal disease authority from the State University of New York at Buffalo, chaired the panel.
It concluded that only three of 17 common ingredients and ingredient combinations had accumulated enough evidence to be regarded as safe and effective: Stannous fluoride in toothpastes; cetlypyridinium chloride in mouth rinses; and the mouth rinse combination of eucalyptol, menthol, methyl salicylate, and thymol.
The panel decided that there was insufficient evidence about the effectiveness of 14 other ingredients and combinations, including hydrogen peroxide; baking soda or sodium bicarbonate; aloe vera; sanguinaria extract; sodium lauryl sulfate; and zinc citrate.
Hydrogen peroxide and baking soda, both as individual ingredients and in combination, did not warrant an “effective” ranking, the panel concluded.
“Because of a lack of properly designed studies showing conclusively that the combination of hydrogen peroxide and sodium bicarbonate is effective, this combination of ingredients does not appear to present any added benefit to oral hygiene products,” the report stated.
It criticized past studies as too small and flawed in many ways, “further clouding the already contradictory results” about peroxide and baking soda.
Previous studies raised concerns that daily use of mouth rinses containing high amounts of alcohol could increase the risk of oral cancer.
The committee, however, concluded that their is no proof of such a link, but recommended further studies.