The majority of the LISTERINE® range contains four Essential Oils, which are antibacterial antiplaque agents, and are proven to penetrate the biofilm. The oils are eucalyptol 0.092%, thymol 0.064%, methyl salicylate 0.060% and menthol 0.042%. The LISTERINE® Total Care products also contain 220 ppm fluoride.

Adding LISTERINE® to a dental care regime can reduce plaque levels significantly more than brushing and flossing alone,1 with plaque reduction with LISTERINE® demonstrated in 9 published studies of 6 months' duration conducted over the last 20 years.1–9 In one six month study, the adjunctive use of LISTERINE® produced an incremental whole-mouth plaque reduction of nearly 52% when compared with brushing and flossing alone.1

Plaque biofilm is the main cause of gum disease and dental caries, and plaque re-growth on teeth begins immediately after brushing.

Bacteria in biofilm are more resistant to antimicrobial agents than free-floating, planktonic bacteria because biofilms form a shield, impeding access of agent, and bacteria may undergo phenotypic changes within biofilm that increase resistance.10 Mouth rinses that are effective against planktonic bacteria may not be effective against bacteria in biofilm.11

As an adjunct to brushing and flossing, LISTERINE® is a mouth rinse that can kill a broad spectrum of planktonic bacteria and penetrate deep into the biofilm, allowing the antibacterial agents to act on sessile bacteria (bacteria in biofilm),11 reducing the overall bacterial burden in the mouth.12 LISTERINE® penetrates deep into the biofilm to kill significant numbers of plaque-bacteria.11–12


Representative images of biofilm after 48 hours.


This study investigated the effect of rinsing with LISTERINE® on levels of representative subgingival bacteria in subjects with mild-to-moderate periodontitis.1


Daily brushing and flossing are more effective at controlling plaque when LISTERINE® is added. In this randomised, placebo controlled, unsupervised study, 246 patients were assigned to brushing + control rinse, brushing + flossing + control rinse or brushing + flossing + LISTERINE® for 6 months; patients were evaluated for a number of measures including Plaque Index. When used for 6 months, the adjunctive use of LISTERINE®, produces an incremental whole-mouth plaque reduction of 51.9%, compared with brushing and flossing alone.1


A summary of published long-term randomised, controlled, double-blinded clinical trials with LISTERINE® over the past 20 years1–9


The essential oilzs in LISTERINE® have a range of antimicrobial activities 
• Non-specific mechanism of action, killing bacteria by disruption of cell walls1
• Broad antimicrobial effects (aerobes, anaerobes, Gram-negative and Gram-positive organisms and yeasts)1–4
• Reduces bacterial endotoxins and plaque pathogenicity5,6
• Penetrates plaque biofilm7,8
• Antibacterial activity (slowing re-colonisation) continues after rinsing2,4,9
• No shift in oral microbial flora that might favour growth of opportunistic species10


  1. Sharma N et al. Adjunctive benefit of an essential oil containing mouthrinse in reducing plaque and gingivitis in patients who brush and floss regularly. A six-month study. J Am Dent Assoc 2004; 135: 496–504.
  2. Overholser CD et al. Comparative effects of two chemotherapeutic mouthrinses on the development of plaque and gingivitis. J Clin Periodont 1990; 17: 575–579.
  3. Charles C et al. Comparative efficacy of an antiseptic mouthrinse and an antiplaque/antigingivitis dentifrice. A six-month clinical trial. J Am Dent Assoc 2001; 132: 670–675.
  4. Sharma NC et al. Comparative effectiveness of an essential oil mouthrinse and dental floss in controlling interproximal gingivitis and plaque. Am J Dent 2002; 15: 351–355.
  5. Bauroth K et al. The efficacy of an essential oil antiseptic mouthrinse vs. dental floss in controlling interproximal gingivitis: a comparative study. J Am Dent Assoc 2003; 134: 359–365.
  6. Charles CH et al. Comparative antiplaque and antigingivitis effectiveness of a chlorhexidine and an essential oil mouthrinse: 6-month clinical trial. J Clin Periodont 2004; 31(10): 878–884.
  7. Tufekci E et al. Effectiveness of an essential oil mouthrinse in improving oral health in orthodontic patients. Angle Orthod 2008; 78(2): 294–298.
  8. Sharma NC et al. Superiority of an essential oil mouthrinse when compared with a 0.05% cetylpyridinium chloride containing mouthrinse: a six-month study. Int Dent J 2010;60(3): 175–180.
  9. Cortelli et al. Comparative antiplaque and antigingivitis efficacy of a multipurpose essential oil-containing mouthrinse and a cetylpyridinium chloride-containing mouthrinse: A 6-month randomized clinical trial. Quintessence Int 2012; 43(7): e82–94.
  10. Barnett ML. The role of therapeutic antimicrobial mouthrinses in clinical practice: control of supragingival plaque and gingivitis. J Am Dent Assoc 2003; 134: 699–704.
  11. Fine DH et al. Comparative antimicrobial activities of antiseptic mouthrinses against isogenic planktonic and biofilm forms of Actinobacillus actinomycetemcomitans. J Clin Periodontol 2001; 28: 697–700.
  12. Fine DH et al. In vivo antimicrobial effectiveness of an essential oil-containing mouth rinse 12 h after a single use and 14 days' use. J Clin Periodontol 2005; 32: 335–340.