Effectiveness of mechanical tongue cleaning on breath odour and tongue coating: a systematic review

Abstract

The objective of this review was to summarize the available evidence regarding the effects of mechanical tongue cleaning compared with no mechanical tongue cleaning on breath odour and tongue coating (TC). PubMed-MEDLINE, EMBASE and Cochrane-CENTRAL were searched to identify potentially relevant studies. The inclusion criteria included the following: randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs) conducted in humans in good general health (no systemic disorders) and a patient age of ≥17 years. For the intervention, we considered tongue cleaning [the use of a tongue scraper (TS) or tongue brush (TB)] and for the control, brushing only (B) groups. Clinical parameters such as volatile sulphur compound concentration, organoleptic scores and TC were the outcome variables of interest. Study selection, quality assessment and data extraction were carried out by two independent reviewers. After screening of the titles and abstracts and subsequent full text reading of the potential papers, we identified five publications that met the eligibility criteria and provided seven experiments. The five studies consisted of three RCTs and two CCTs. All experiments show a positive effect of mechanical tongue cleaning in addition to toothbrushing on various parameters of oral malodour. This review demonstrated that mechanical approaches, such as tongue brushing or tongue scraping to clean the dorsum of the tongue, have the potential to successfully reduce breath odour and TC. However, data concerning the effect of mechanical tongue cleaning on chronic oral malodour (halitosis) are insufficient.