Reducing plaque bacteria and managing biofilm

reducing plaqueClinical Dentistry magazine explores how an essential oils mouthwash, when used as an adjunct, may help to reduce plaque bacteria and manage biofilm.

Plaque bacteria are considered a major cause of periodontal disease (Page and Kornman, 1997). It has been established that good plaque control is an essential part of preventing gingivitis and periodontitis, which are a continuum of the same disease (Kinane and Attström, 2005; Chapple et al, 2015).

Toothbrushing and interdental cleaning are acknowledged as the mainstay of preventive oral care (Barnett, 2006). According the Adult Dental Health Survey 2009, 66% of dentate adults in England, Wales and Northern Ireland have visible plaque even though 75% of respondents claimed to brush their teeth twice a day and 25% of those reported cleaning interdentally daily.

Bridging the gap

Some suggest that using an antimicrobial mouthwash may offer an additional means for plaque control (Barnett, 2006).

In 2015, Chapple and colleagues reported back from Working Group 2 of the 11th European Workshop in Periodontology, concluding: ‘[…] where improvements in plaque control are required, adjunctive use of antiplaque chemical agents may be considered. In this scenario, mouth rinses may offer greater efficacy but require an additional action to the mechanical oral hygiene regime’.

Additionally, an updated evidence base reaffirms the role of mouthwash in gum health. Figuero and colleagues conducted a systematic review and meta-analysis exploring the adjunctive use of 11 mouthwash formulations in 2020.

Their investigation established that adjunctive antiseptics in mouthwash provide statistically significant reductions in plaque. This is compared to mechanical plaque controls at six months.

They also came to the conclusion that: ‘… despite the high variability in the number of studies comparing each active agent and the different risks of bias, CHX [chlorhexidine] and EOs [essential oils], in mouthrinses appeared to be the most effective active agents for plaque … control’ (Figuero et al, 2020).

Statistics show…

The Figuero and colleagues’ (2020) outcomes add to the pre-existing evidence base presented by Araujo and colleagues (2015), which was the first meta-analysis to demonstrate the clinically significant, site-specific benefit of adjunctive essential oil mouthwash in people within a six-month period (that is, between dental visits).

The analysis revealed that 36.9% of subjects using mechanical methods with essential oil-containing mouthwash experienced at least 50% plaque-free sites after six months, compared to just 5.5% of patients using mechanical methods alone (Araujo et al, 2015).

Araujo and colleagues (2015) concluded that the: ‘Addition of daily rinsing with an EO [essential oil] mouthwash to mechanical oral hygiene provided statistically significantly greater odds of having a cleaner […] mouth, which may lead to prevention of disease progression.’

Supportive advice

The current evidence base indicates that, with the daily use of an essential oil-containing mouthwash, patients have statistically significant greater odds of achieving a reduction in plaque beyond using mechanical methods alone (Araujo et al, 2015).

A mouthwash containing essential oils may therefore prove a worthwhile adjunct for patients. Particularly those who struggle to control oral biofilm via brushing and interdental cleaning alone (Chapple et al, 2015; Araujo et al, 2015).

The efficacy of essential oils

When used as an adjunct to mechanical cleaning, Listerine Total Care, an essential oil mouthwash, manages plaque levels, to help prevent gingivitis (Boyle, Koechlin and Autier, 2014).

Listerine Total Care may support the efforts of a patient requiring early intervention, by virtue of its essential oil formulation consisting of eucalyptol, thymol, menthol and methyl salicylate, all of which are proven to:

  • Penetrate the plaque biofilm (Pan et al, 2000)
  • Manage the bacterial load of the mouth (Minah et al, 1989)
  • Reduce maturation of remaining biofilm colonies (Johnson & Johnson. Data on file (2)).


Page RC, Kornman KS (1997) The pathogenesis of human periodontitis: an introduction. Periodontology 2000 14: 9-11

Kinane DF, Attström R (2005) Advances in the pathogenesis of periodontitis. Group B consensus report of the fifth European Workshop in Periodontology. J Clin Periodontol 32(Suppl. 6): 130-1

Chapple IL, Van der Weijden F, Doerfer C, Herrera D, Shapira L, Polak D, Madianos P. Louropoulou A, Machtei E, Donos N, Greenwell H, Van Winkelhoff AJ, Eren Kuru B, Arweiler N, Teughels W, Aimetti M, Molina A, Montero E, Graziani F (2015) Primary prevention of periodontitis: managing gingivitis. J Clin Periodontol 42 (Suppl.16): S71-S76

Barnett ML (2006) The rationale for the daily use of an antimicrobial mouthrinse. J Am Dent Assoc 137: 16S-21S

Adult Dental Health Survey 2009. The Health and Social Care Information Centre 2011

Figuero E, Roldán S, Serrano J, Escribano M, Martín C, Preshaw PM (2020) Efficacy of adjunctive therapies in patients with gingival inflammation. A systematic review and meta-analysis. J Clin Periodontol 47(Suppl 22): 125-143

Araujo MWB, Charles CA, Weinstein RB, McGuire JA, Parikh-Das AM. Du Q, Zhang J, Berlin JA, Gunsolley JC (2015) Meta-analysis of the effect of an essential oil-containing mouthrinse on gingivitis and plaque.  J Am Dent
Assoc 146(8): 610-622

Boyle P, Koechlin A, Autier P (2014) Mouthwash use and the prevention of plaque, gingivitis and caries. Oral Dis 20(Suppl 1): 1-68

Pan P, Barnett ML, Coelho J, Brogdon C, Finnegan MB (2000) Determination of the in situ bactericidal activity of an essential oil mouthrinse using a vital stain method. J Clin Periodontol 27(4): 256-261

Minah GE, DePaola LG, Overholser CD, Meiller TF, Niehaus C, Lamm RA, Ross NM. Dills SS (1989) Effects of 6 months use of an antiseptic mouthrinse on supragingival dental plaque microflora. J Clin Periodontol 16(6): 347-352

This article first appeared in Clinical Dentistry magazine. Subscribe to the latest issue of Clinical Dentistry magazine here.

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