A Chemical-Mechanical Tongue Cleaning Method: An Approach to Control Halitosis and to Remove the Invisible Tongue Biofilm, A Possible Cause of Persistent Taste Disorder

Tongue coating or tongue biofilm is the main and most common cause of halitosis, as shown by numerous studies. There are four types of lingual papillae, three of which contain taste buds (vallate, fungiform, and foliate papillae). The filiform papillae are the most numerous and although they do not have taste cells, they surround the fungiform papillae and are in contact with the vallate and foliate papillae, which have taste buds. The anatomy of a single filiform papilla shows that it is not a simple bud coming out of the surface of the tongue, but a group of individual filaments in within the tongue biofilm can accumulate. In case of shear forces exerted on the papillae (i.e., the use of a tongue scraping), the sturdy papillae bend slightly and protect the then embedded biofilm remaining in the interstitial volume. Tongue coating may thus physically limit tastants’ access to taste pores and thus prevents their binding to taste receptors. A chemical-mechanical tongue cleaning technique (DC technique) can reach this biofilm with a better efficiency than the traditional methods to clean the tongue, such as the use of a tongue scraper or a toothbrush. DC technique removed 67,5% more coating than the tongue scraper and 148% more than the toothbrush. Further research should compare these methods concerning taste disorders.