Efficacy of two mouthwashes on 3-day supragingival plaque regrowth: a randomized crossover clinical trial

Int J Dent Hyg. 2017 Feb;15(1):73-80. doi: 10.1111/idh.12185. Epub 2015 Nov 2.


Background: The aim of this study was to evaluate the antiplaque effects of an alcohol-free essential oil (alcohol-free EO) mouthwash and an amine fluoride/stannous fluoride with zinc lactate (SnFl-Zn) mouthwash compared to a positive control of chlorhexidine (CHX) mouthwash, using an in vivo plaque regrowth model of 3 days.

Materials and methods: The study was designed as a double-masked, randomized, crossover clinical trial, involving 20 volunteers to compare two different mouthwashes, using a 3-day plaque accumulation model. After receiving thorough professional prophylaxis at baseline, over the next 3 days, each volunteer refrained from all oral hygiene measures and performed two daily rinses with 20 ml of the test mouthwashes. A 0.20% CHX rinse served as a positive control. At the end of each experimental period, plaque was assessed, and the panellists completed a questionnaire. Each subject underwent a 14-day washout period, and then, there was another allocation.

Results: The SnFl-Zn mouthwash has shown a better inhibitory activity on plaque regrowth compared to the alcohol-free EO mouthwash in the whole mouth (plaque index = 1.93 against 2.45, respectively), but there was less of an effect compared to the CHX group, with an overall plaque index of 1.41. The differences of 0.52 between alcohol-free EO and SnFl-Zn and between SnFl-Zn and CHX and of 0.96 between alcohol-free EO and CHX were all statistically significant (P < 0.001).

Conclusion: The alcohol-free EO mouthwash seemed to have less of an inhibiting effect on plaque regrowth than the amine fluoride/SnFl-Zn mouthwash and the CHX control.

Keywords: alcohol free; chlorhexidine; dental plaque; essential oils; fluoride; mouthrinse; mouthwashes.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Anti-Infective Agents, Local / administration & dosage
  • Anti-Infective Agents, Local / therapeutic use
  • Chlorhexidine / administration & dosage
  • Chlorhexidine / therapeutic use
  • Cross-Over Studies
  • Dental Plaque / prevention & control*
  • Dental Plaque Index
  • Double-Blind Method
  • Female
  • Fluorides, Topical / administration & dosage
  • Fluorides, Topical / therapeutic use
  • Humans
  • Male
  • Mouthwashes / administration & dosage
  • Mouthwashes / therapeutic use*
  • Surveys and Questionnaires
  • Tin Fluorides / administration & dosage
  • Tin Fluorides / therapeutic use
  • Treatment Outcome
  • Young Adult


  • Anti-Infective Agents, Local
  • Fluorides, Topical
  • Mouthwashes
  • Tin Fluorides
  • amine fluoride solution
  • Chlorhexidine