Mouthwash formulas in focus

The recently launched OH Challenge asked:

When used for 6 months or longer, which mouthrinse formulations have been found to be most effective in controlling plaque as an adjunct to standard care*?

* Boyle P et al. Mouthwash use and the prevention of plaque, gingivitis and caries. Oral. Dis. 2014; 20 (Suppl. 1): 1-68

With just 38% of respondents answering the questions correctly, the aim of this article is to help deliver the supporting evidence, to clarify the situation.

Prasad and colleagues (2016) conducted a systematic review exploring the clinical effectiveness of post-brushing rinsing in reducing plaque. This was, in part, because they recognised that, while oral hygiene maintenance using mechanical means is very important, for some it can be insufficient when it comes to plaque control due to its, ‘[…] dependence on dexterity and thoroughness of the individuals as well as their compliance […]’.1

Building on the idea that there is a place for mouthwash as an adjunct to mechanical cleaning, Boyle and colleagues (2014) performed a quantitative assessment of data to explore mouthwash use and the risk of common oral conditions. They considered the differences between chlorhexidine (CHX), cetylpyridinium (CPC) essential oils (EO), triclosan and delmopinol, and found evidence supporting the use of mouthwash in controlling dental plaque.2

They concluded that that, over a period of less than three months, mouthwashes containing CHX were the most effective of the preparations considered, resulting in a reduction of dental plaque.2

Furthermore, when used for 6 months or longer, EO mouthwashes equalled or exceeded the effect of CHX in controlling plaque as an adjunct to standard care.2

It was further found that mouthwashes containing CPC or triclosan may also be effective, but less so than CHX or an EO formulation, while mouthwash preparations containing delmopinol are ineffective in terms of plaque control.2

A closer look at CHX and EO

Following a systematic review, Prasad and colleagues (2016) came to a similar conclusion to Boyle et al (2016). They sourced evidence indicating that EO and CHX formulations offer the greatest chance of success in terms of providing long-term plaque control.1

However, they also recognised that CHX presented some potential complications including altering the user’s taste, excess formation of supragingival calculus, and tooth discolouration. They wrote that these issues question, ‘[…] the efficacy for [CHX’s] long term use.’1

More recently, James and colleagues (2017) conducted a Cochrane review of CHX mouthrinse as an adjunctive treatment for gingival health. The evidence supported the efficacy of CHX in addition to, ‘[…] usual toothbrushing and cleaning for four to six weeks or six months […]’, since its use led to a ‘large’ decrease in plaque accumulation.3

On the other hand, they also reported: ‘Rinsing for 4 weeks or longer causes tooth staining, which requires scaling and polishing carried out by a dental professional. Other side effects have been reported, including build-up of calculus (tartar), temporary taste disturbance and temporary shedding of/damage to the lining of the mouth.’3

Meanwhile, in 2015, Araujo and colleagues’ (2015) meta-analysis demonstrated the clinically-relevant benefits of an essential oil-containing mouthrinse in site-specific areas of the mouth, when used as an adjunct to mechanical cleaning over a six-month period.4

The evidence examined supports the idea that using an essential oil-containing mouthrinse on a daily basis offers a clinically relevant benefit beyond that offered by mechanical cleaning alone.4

This adds to the body of evidence in support of EO mouthwash, including Haas and colleagues’ (2016) meta-analysis and meta-review into the effect of EO-containing mouthwash on plaque, which found that: ‘Mouthwashes containing essential oils should be considered the first choice for daily use as adjuvants to self-performed mechanical plaque control.’5

Making evidence-based choices

As suggested by Prasad and colleagues (2016), there are several elements to take into consideration, including any potential disadvantages that may result from their use, when choosing which mouthrinse formulation to recommend.1

Summing up, they wrote: ‘[…] health professionals should regularly review products and have complete knowledge about the products and their efficacy based on evidence before prescribing to the patients.’1

This is something that was also emphasised by Tillis and Carey (2017), who wrote, ‘When a practitioner is working with a patient to improve oral health by reducing plaque […], being able to provide the patient with an evidence-based strategy is key to success.’6



  1. Prasad M et al. The clinical effectiveness of post-brushing rinsing in reducing plaque and gingivitis: a systematic review. Journal of Clinical and Diagnostic Research 2016; 10(5) ZE01-ZE07
  2. Boyle P et al. Mouthwash use and the prevention of plaque, gingivitis and caries. Head & Neck Oral Diseases 2014; 20(1): 1-68
  3. James P et al. Chlorhexidine mouthrinse as an adjunctive treatment for gingival health (Review). The Cochrane Collaboration. John Wiley & Sons Ltd, 2017
  4. Araujo MWB et al. Meta-analysis of the effect of an essential oil-containing mouthrinse on gingivitis and plaque. JADA 2015; 146(8): 610-622
  5. Haas AN. Essential oils-containing mouthwashes for gingivitis and plaque: Meta-analyses and meta-regression. Journal of Dentistry 2016; 55: 7-15
  6. Tillis T, Carey CM. Review analysis & evaluation. As an adjunct to mechanical oral hygiene, essential-oil containing mouthwash, compared to floss, cetylpyridinium chloride, or placebo may be more effective in reduction of plaque and gingivitis. J Evid Base Dent Pract 2017: 1-3