Effect of rinsing time on antiplaque-antigingivitis efficacy of listerine.

This double-blind, controlled clinical study compared the effectiveness of 30- and 60-s listerine rinses in both inhibiting the development of, and reducing existing, supragingival plaque and gingivitis, using an experimental gingivitis model. 94 subjects completed this study. For each subject, a modified gingival index, modified Quigley-Hein plaque index and Eastman interdental bleeding index were recorded at baseline and at 2 weeks. Following the baseline examinations, subjects received half-mouth prophylaxes, and began 2 x daily supervised rinsing either with listerine for 30 or 60 s or with a control mouthrinse for 30 s as their sole oral hygiene measure. Statistical analysis (ANCOVA) showed that both the 30- and 60-s listerine rinses were significantly (p < 0.01) more effective than the control in inhibiting and reducing plaque, gingivitis and gingival bleeding. Although 60-s rinses with listerine were significantly more effective (p < 0.01) than 30-s rinses in controlling plaque, the 2 rinse durations were similarly effective in controlling interdental bleeding and gingivitis. This study confirms the recommendation of 2x daily rinsing with listerine for 30 s as an effective regimen for gingivitis control.