Bad Breath

Mouth rinses and halitosis (bad breath)

Mouth rinse has a role in tackling plaque and gum health, with studies showing improvements in both these parameters of oral health compared to mechanical cleaning alone. Mouth rinse can deliver high levels of fluoride and therefore has a potential adjunctive role in patients with enamel erosion. Mouth rinse has also been formulated to contain ingredients that relieve dentine hypersensitivity, such as potassium nitrate.

Patients however often have other concerns. Mouth rinses have traditionally been understood to have a role in maintaining breath freshness/tackling halitosis, and some mouth rinses make claims for teeth whitening/prevention of staining.

Halitosis is believed to affect about 25–30% of world's population. This includes categories of genuine halitosis and pseudo-halitosis (including halitophobia, a highly exaggerated fear of bad breath).1

Extraoral sources of halitosis are responsible for 10–20% of halitosis cases and are caused by poor diet, alcohol abuse, tobacco smoking, certain drugs and diseases of other parts of the digestive tract as well as some systemic conditions. Halitosis should therefore be investigated by the dentist as it may be a symptom of a problem that requires professional treatment.1

In 80–90% of cases halitosis has its origins in the oral cavity and the most common causes are gingival pathologies, caries and poor oral hygiene.1 It is now recognised that the odour associated with halitosis from the oral cavity is caused by volatile sulphur compounds, such as hydrogen sulphide, methyl mercaptan, dimethyl sulphide and dimethyl disulphide. These are created by the activity of gram-negative oral micro-organisms, fermenting sulphur-containing proteinaceous substrates.2

The antibacterial mouth rinse LISTERINE® has been shown to significantly reduce levels of odourigenic bacteria in the mouth, levels of volatile sulphorous compounds and to reduce levels of mouth odour.3–5

The treatment of halitosis will include good oral care by the dental team.6 As smoking often contributes to malodour, this may encourage patients to quit.7


  1. Zalewska A et al. Halitosis--a common medical and social problem. A review on pathology, diagnosis and treatment. Acta Gastroenterol Belg 2012; 75(3): 300–309.
  2. Tonzetich J. Production and origin of oral malodor: a review of mechanisms and methods of analysis. J Periodontol 1977; 48(1): 13–20.
  3. Pianotti R et al. Effects of an antiseptic mouthwash on odorigenic microbes in the human gingival-crevice. J Dent Res 1978; 57(2): 175–179.
  4. Pitts G et al. The in vivo effects of an antiseptic mouthwash on odor-producing microorganisms. J Dent Res 1981; 60(11): 1891–1896.
  5. Pitts G et al. Mechanism of action of an antiseptic, anti-odor mouthwash. J Dent Res 1983; 62(6): 738–742.
  6. American Dental Hygienists' Association. Want some life saving advice? Ask your dental hygienist about understanding and eliminating bad breath. 2010.
  7. Watt RG & Daly B. Prevention. Part 1: Smoking cessation advice within the general dental practice. British Dental Journal 2003; 194: 665–668.