Studies show Listerine at least as good as flossing

March 5, 2002
Two studies showed that the antimicrobial action of Listerine® Antiseptic Mouthrinse is "at least as good as" flossing in improving gingival health and plaque reduction, especially in hard to reach areas of the mouth.

Data from two six-month clinical trials comparing the effectiveness of rinsing with an antiseptic mouthwash to daily flossing in fighting plaque and gingivitis are being presented here at the International Association for Dental Research (IADR) Annual Meeting. The two studies showed that the antimicrobial action of Listerine® Antiseptic Mouthrinse is "at least as good as" flossing in improving gingival health and plaque reduction, especially in hard to reach areas of the mouth.

"These findings support the benefit of adding an antiseptic mouthwash to a daily oral health care routine, especially for those patients who don't brush and floss properly," noted Sebastian Ciancio, DDS, distinguished service professor and chair, Department of Periodontics and Endodontics, University at Buffalo School of Medicine & Dentistry. "The findings, however, do not mean that flossing should be replaced with rinsing. I recommend that dentists and hygienists talk to their patients about what's best for their oral healthcare routine, and devise strategies to target difficult to reach areas that are susceptible to plaque accumulation and gingivitis."

Key Findings
In both studies, Listerine was clinically comparable to flossing in controlling interproximal gingivitis and better for plaque reduction. Interproximal plaque accumulation was reduced by 37.5% and 20.0% (p<0.001) respectively, in patients who rinsed twice a day with Listerine. In comparison, those patients who flossed daily showed a 2.1% (p= 0.305) and 3.4% (p=0.134) reduction in interproximal plaque accumulation. Both the Listerine and flossing groups included brushing with regular fluoride-containing toothpaste and were compared with a negative control treatment group that brushed and rinsed with a placebo rinse.

In addition to site-specific plaque reduction, patients who rinsed twice a day with Listerine showed a 7.9% and 11.1% (p<0.001) reduction in interproximal gingivitis versus an 8.3% (p<0.001) and 4.3% (p=0.006) reduction in those who flossed daily.

"These clinical findings support the notion that rinsing with antiseptic mouthwash may complement the mechanical oral-care methods of brushing and flossing," noted Linda DeVore, RDH, MA, professor and chair, Department of Dental Hygiene, Dental School, University of Maryland, Baltimore. "Patients who need to improve their plaque control should be encouraged to add rinsing to their daily routine to help improve their oral health."

Study Design
The two, six-month, randomized, evaluator-blinded, controlled, parallel group studies included more than 600 patients, ages 18 to 63 with mild through moderate levels of gingivitis (but without moderate or advanced periodontitis). The studies were conducted at two independent research testing facilities. Researchers at both institutions compared the efficacy of rinsing with Listerine to daily flossing in inhibiting supragingival dental plaque and gingivitis when used as an adjunct to tooth brushing.

To maximize compliance, subjects in the flossing group were provided a flossing demonstration by a dental professional and had to demonstrate correct flossing technique at baseline. All subjects were monitored monthly for compliance with their assigned regimen. Subjects then began their regimen of usual tooth brushing plus rinsing with their assigned mouthrinse (Listerine or placebo rinse) for 30 seconds, twice daily for 6 months or tooth brushing plus flossing once daily. Patient re-examinations were conducted at three and six-months post-baseline.

Implications for Oral Health Care
These studies further confirm Listerine's effectiveness on improving gingival health and plaque reduction on interproximal sites, which are typically considered hard to reach areas.

"Although some of my patients claim to brush and floss regularly, my clinical experience shows that many are not adequately removing difficult to access plaque, which can lead to the development of gingivitis," noted Dr. Ciancio. "Left untreated, gingivitis can lead to periodontitis (advanced gum disease) and eventual tooth loss."