Title: 0211 - Comparison of Antimicrobial Action of Three Commercial Mouthwashes and Saline


Qingru Jiang (Presenter)
University of Helsinki and Helsinki University Hospital

Iva Stamatova, University of Helsinki and Helsinki University Hospital
Sok-Ja Janket, Forsyth Institute
Veera Kainulainen, University of Helsinki
Riitta Korpela, University of Helsinki
Jukka Meurman, University of Helsinki and Helsinki University Hospital


Objectives: To evaluate the antimicrobial effects of three commercial mouthwashes in comparison to physiological saline in experimental multi-species oral biofilms; To compare the susceptibilities of microbial strains to each mouthwash.

Methods: We constructed multi-species biofilms in vitro, containing Lactobacillus rhamnosus GG (probiotic, LGG), Aggregatibacter actinomycetemcomitans, Candida albicans, Fusobacterium nucleatum, Streptococcus mutans, and Streptococcus sanguinis. These biofilms were exposed to chlorhexidine (Corsodyl®), essential oils (Listerine®), and amine fluoride/stannous fluoride (Meridol®) for 1 minute, respectively. The physiological saline was used as the negative control. Viable cells were counted as colony-forming units (CFUs) and the survival rates of microbes were calculated by dividing viable CFUs by the inoculated microbes. Survival rates of combined microbes were compared on day1 and day3 after exposure to each mouthwash. All the biofilms were stained with Live/Dead® kit and scanned using confocal laser scanning microscopy for structural analysis. All the experiments were conducted in triplicate and averages were used for statistical analyses.

Results: The survival rates and microscopy images demonstrated that all the tested mouthwashes showed immediate antimicrobial effect on the biofilms. The survival rates of the strains on the 1-day biofilms treated with all the mouthwashes were significantly lower than those treated with saline (p<0.05). Essential oils demonstrated the best microbial growth suppression in both 1-day and 3-day biofilms. The median relative survival rates of LGG were lower than those of S. mutans, S. sanguinis, and C. albicans when treated with each mouthwash in both the 1-day and 3-day biofilms.

Conclusions: In this experimental biofilm model, all three mouthwashes demonstrated significant antimicrobial actions compared with saline. Moreover, essential oils showed the best antimicrobial effects compared with chlorhexidine or amine fluoride/stannous fluoride. Probiotic LGG was the most susceptible strain to the tested mouthwashes.

This abstract is based on research that was funded entirely or partially by an outside source:
China Scholarship Council (201206310016), Finnish Dental Society Apollonia and Finnish Dental Foundation, and Academy of Finland (No. 285632).

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE