A company earns the ADA Seal for its product by providing evidence that meets the ADA criteria for safety and efficacy. The ADA Council on Scientific Affairs carefully evaluates the evidence according to the Guidelines for Participation in the ADA’s Seal of Acceptance Program
. In addition, the ADA Council has adopted a specific guideline for this product category called Chemotherapeutic Products for Control of Gingivitis
. The Guideline includes, but is not limited to, the following criteria:
- Two independent, well designed, 6-month clinical studies utilizing a placebo control showing significant reduction in gingivitis for the test product vs. the control
- Data showing that the plaque bacteria do not become resistant to the test product
- Data showing that the test product does not allow pathogenic or opportunistic plaque bacteria to flourish
- Data showing that oral soft tissues and teeth are not harmed
- Toxicology and mutagenicity studies to assess possible adverse effects at the cellular level
In lieu of the bulleted items listed above, there is another, equally valid way that some mouthrinses may demonstrate safety and efficacy by using surrogate tests
. These tests measure surrogates that have been shown to correlate with the control of plaque and gingivitis. Well-designed surrogate tests are much quicker and easier to do than clinical studies, and are just as valid at showing product effectiveness. A company may elect to perform surrogate tests rather than clinical studies if its mouthrinse contains the same active agent combination of essential oils as a clinically tested mouthrinse. The company is required to demonstrate that its product behaves the same as the clinically tested product on the following surrogate tests:
- Oral irritation/sensitization clinical study
- Determination of minimal inhibitory concentration, minimal bactericidal concentration and kill time of product on plaque bacteria
The following clinical studies
were submitted for Acceptance of Listerine Antiseptic. Some of the studies lack reference to a publication. This means that the company has not published the study. Copies may be available on request from the company. Contact information is provided below.
Lamster IB, Alfano MC, Seiger MC, Gordon JM (1983). The effect of Listerine antiseptic on reduction of existing plaque and gingivitis. Clin Prevent Dent 5:12-16, 1983:
This was a 6-month trial. Subjects were assigned to one of three products: Listerine, a control mouthrinse containing 26.9% alcohol, and a control mouthrinse with sterilized colored water. Study results showed significant reduction in plaque and gingivitis when compared with water and 26.9% alcohol mouthrinses.
Gordon, J.M.; Lamster, l.B.; and Sieger, M.C.Efficacy of Listerine antiseptic in inhibiting the development of plaque and gingivitis. J Clin Periodont. 1985 Sep;12(8).
This was of 9-month duration and had 3 groups: Listerine, a control mouthrinse containing 26.9% alcohol, and a control mouthrinse with sterilized color water. Results demonstrated that Listerine significantly reduced the development of plaque at 1, 3, 6 and 9 months and reduced the severity of gingivitis at 9 months when compared to water and control mouthrinse.
DePaola LG, Overholser CD, Meiller TF, Minah GE, Niehaus C
. J Clin Periodont 1989 May;16(5) Chemotherapeutic inhibition of supragingival dental- plaque and gingivitis development.)
This was a 6 month study to determine the effect of Listerine when compared with a 5% hydro alcohol control on the development of dental plaque and gingivitis. Results showed a significant inhibition of plaque and gingivitis after 6 months when compared with the hydro alcohol control.
Microbiology Effectiveness Studies:
Two independent 6-month microbiological studies were conducted to evaluate the effect of Listerine Antiseptic on the microbiological composition of dental plaque. These studies showed that Listerine Antiseptic remained effective against plaque bacteria over the six months of the study.
Microbiological Safety Studies:
Two independent 6-month microbiological studies were conducted to evaluate the effect of Listerine on the microbiological composition of dental plaque. These studies showed that Listerine Antiseptic did not contribute to a significant increase in opportunistic or pathogenic plaque bacteria over the six months of the study.
Other Safety studies:
Toxicology studies showed no adverse reactions.
Mutagenicity studies using the Ames rat-hepatocyte DNA
repair, and mice micronucleus tests, show no mutagenic effects. In two 6-month and one 9-month clinical studies, soft tissue condition and extrinsic tooth stain were evaluated at baseline and at each subsequent examination interval. There were no mucosal aberrations or development of extrinsic tooth stain at either 6 or 9
months in any of these studies.