Mouthrinses for the treatment of halitosis

Halitosis is an unpleasant odour emanating from the oral cavity. Mouthwashes, which are commonly used for dealing with oral malodour, can be generally divided into those that neutralize and those that mask the odour.

To investigate the effects of mouthrinses in controlling halitosis.

We searched the following databases: Cochrane Oral Health Group Trials Register (to August 2008); the Cochrane Central Register of Controlled Trials (The Cochrane Library 2008, Issue 3); MEDLINE (1950 to August 2008); EMBASE (1980 to August 2008); and CINAHL (1982 to August 2008). There were no language restrictions.

Randomised controlled trials (RCTs) comparing mouthrinses to placebo in adults over the age of 18 with halitosis and without significant other comorbidities or health conditions.The primary outcomes considered were self expressed and organoleptic (human nose) assessments of halitosis, and the secondary outcomes included assessment of halitosis as measured by a halimeter, portable sulphide monitor or by gas chromatography coupled with flame-photometric detection.

Two independent review authors screened and extracted information from, and independently assessed the risk of bias in the included trials.

Five RCTs, involving 293 participants who were randomised to mouthrinses or placebo, were included in this review.In view of the clinical heterogeneity between the trials, pooling of the results and meta-analysis of the extracted data was not feasible and therefore only a descriptive summary of the results of the included trials is provided.0.05% chlorhexidine + 0.05% cetylpyridinium chloride + 0.14% zinc lactate mouthrinse significantly reduced the mean change (standard deviation (SD)) of organoleptic scores from baseline compared to placebo (-1.13 (1.1) P < 0.005 versus -0.2 (0.7)) and also caused a more significant reduction in the mean change (SD) in peak level of volatile sulphur compounds (VSC) (-120 (92) parts per billion (ppb) versus 8 (145) ppb in placebo). The chlorhexidine cetylpyridinium chloride zinc lactate mouthrinse showed significantly more tongue (P < 0.001) and tooth (P < 0.002) staining compared to placebo.However, in view of the incomplete reporting of results in three of the trials and the sole use of the halimeter for assessment of VSC levels as outcomes in two further trials, caution should be exercised in interpreting these results.

Mouthrinses containing antibacterial agents such as chlorhexidine and cetylpyridinium chloride may play an important role in reducing the levels of halitosis-producing bacteria on the tongue, and chlorine dioxide and zinc containing mouthrinses can be effective in neutralisation of odouriferous sulphur compounds.Well designed randomised controlled trials with a larger sample size, a longer intervention and follow-up period are still needed.