Comparative effectiveness of an essential oil mouthrinse and dental floss in controlling interproximal gingivitis and plaque

Am J Dent. 2002 Dec;15(6):351-5.


Purpose: To compare the effectiveness of rinsing with an essential oil-containing antimicrobial mouthrinse with that of dental floss in reducing interproximal gingivitis and plaque in an unsupervised 6-month clinical trial designed in accordance with ADA Acceptance Program Guidelines.

Materials and methods: 319 qualifying subjects, aged 18-63, were randomized into one of three groups: essential oil mouthrinse (Listerine Antiseptic); dental floss (Reach Dental Floss); or a negative control rinse. At baseline, subjects received a complete oral soft tissue examination and scoring of the Modified Gingival Index (MGI), modified Quigley-Hein Plaque Index (PI), and bleeding index (BI). Following a complete dental prophylaxis and receiving flossing or rinsing instructions, subjects started on their respective regimen. They continued on their assigned regimen unsupervised at home, in addition to toothbrushing, and were reexamined at 3 and 6 months. The treatment groups were compared with respect to baseline demographic and clinical variables. The primary efficacy variables were mean interproximal MGI and PI at 6 months. Intergroup differences at 3 and 6 months were tested using a one-way analysis of covariance model with treatment as a factor and the respective baseline value as the covariate. In addition, the essential oil mouthrinse was compared to floss for interproximal gingivitis reduction using "at least as good as" statistical criteria.

Results: 301 subjects were considered evaluable. There were no statistically significant differences among the 3 groups at baseline, with the exception of the essential oil mouthrinse group having significantly fewer AfroAmerican subjects than the other two groups. For the interproximal MGI, the essential oil mouthrinse and flossing were both significantly more effective than the negative control (P < 0.001) at 3 and 6 months. The essential oil mouthrinse was shown to be "at least as good as" dental floss for the control of interproximal gingivitis. For the interproximal PI, the essential oil mouthrinse was significantly more effective than the negative control at 3 and 6 months (P < 0.001) while flossing was significantly more effective than the negative control at 3 months (P < 0.05) but not at 6 months. The essential oil mouthrinse was significantly more effective than floss (P < 0.001) at both these time periods.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Chi-Square Distribution
  • Dental Devices, Home Care*
  • Dental Plaque / prevention & control*
  • Dental Plaque Index
  • Drug Combinations
  • Female
  • Gingivitis / prevention & control*
  • Humans
  • Least-Squares Analysis
  • Male
  • Middle Aged
  • Mouthwashes / therapeutic use*
  • Oils, Volatile / therapeutic use*
  • Periodontal Index
  • Salicylates / therapeutic use*
  • Terpenes / therapeutic use*


  • Drug Combinations
  • Mouthwashes
  • Oils, Volatile
  • Salicylates
  • Terpenes
  • Listerine