Halitosis, commonly known as bad breath, is often caused by bacteria and food debris accumulating on the tongue’s surface. Among various treatments, mechanical tongue cleaning using scrapers or brushes is frequently recommended. A Cochrane systematic review led by Outhouse et al. analyzed two randomized controlled trials (RCTs) with a total of 40 participants to evaluate how tongue scraping compares to other methods for reducing oral malodor (Outhouse et al., 2006).

The included trials measured changes in volatile sulfur compounds (VSCs), which are responsible for the characteristic odor of bad breath. In one trial, the tongue cleaner reduced VSC levels by 42%, the tongue scraper by 40%, and a regular toothbrush by 33%. However, the effects were short-lived, with odor reductions disappearing within 30 minutes post-treatment.

In a second trial, the tongue scraper led to a 75% reduction in VSCs, while the toothbrush achieved 45%. Adverse effects such as nausea (60%) and minor trauma (10%) were associated with toothbrush use, but not with tongue scrapers. All participants found tongue scraping acceptable and tolerable.

Despite these promising reductions, the review emphasized that the evidence quality was low and the clinical significance uncertain. Differences in study design and outcome measurement methods made it impossible to perform a meta-analysis. More importantly, the review found no trials that directly compared mechanical tongue scraping with chemical solutions like mouthwashes.

Despite the limited quality of evidence, tongue scrapers are still considered a useful and reliable tool for maintaining oral hygiene. They are simple to use, well-tolerated, and effective at removing odor-causing bacteria from the tongue’s surface.

When combined with regular toothbrushing and the use of mouthwash, tongue scraping can enhance overall breath freshness and serve as a practical addition to daily oral care routines.