Objectives: Tongue cleaning has been advocated to improve oral malodor and to reduce reinfection of periodontal niches by eliminating tongue coating and/or reducing putrefaction by bacteria.
Material and methods: This cross-over, single-blind study on periodontitis-free, non-smoking, subjects with habitual oral hygiene (n=16), evaluated the effect of tongue cleaning (with either plastic scraper or nylon multi-tufted toothbrush), on the microbial load of the tongue dorsum (anterior and posterior of the sulcus terminalis), the extent of tongue coating, and taste sensation for bitter, sweet, salt, and sour. Both devices had been used twice daily for 2 weeks (toothbrush three forward-backward movements along the linea mediana and for each longitudinal third of the tongue; two strokes with the scraper along the linea mediana and along the borders of the tongue).
Results: Two weeks of tongue brushing or scraping resulted in only negligible reductions in aerobic and anaerobic bacteria on the tongue (reductions <0.5 log). The amount of tongue coating, however, decreased significantly (p<0.05), with both devices. The taste sensation improved after 2 weeks of tongue cleaning, especially with the scraper (significant improvements for quinine and sodium chloride).
Conclusion: Tongue cleaning improves taste sensation and seems to reduce the substrata for putrefaction, rather than the bacterial load.