Is the denture microbiota responsible for bad breath?

Actu GP Mauvaise haleine : la faute au microbiote de votre dentier ?

Is bad breath associated to a specific oral microbiota? Thanks to new analytical techniques that are now able to assess more accurately this potential relation, an Israeli study in elderly persons was able to provide us with some answers.


It is estimated that around one out of four people has bad breath, and it is usually related to bacterial activity in the mouth. Its prevalence increases with age and affects more and more people as life expectancy increases. Although the causes of halitosis—the scientific term for bad breath—are generally known (poor oral hygiene, several diseases), bacteria responsible for bad breath have not yet been precisely identified.

New tools

Until recently, scientists did not have the tools needed to identify the microorganisms in the oral cavity which could generate a change in the mouth ecosystem. The development of new analytical techniques truly made a difference and paved the way for more precise studies. Thanks to these advances, researchers from the Tel Aviv University dental geriatric clinic carried out a study in a group of 26 patients with a average age of 71 years wearing a removable complete denture. Their objective was to quantify and qualify the denture odor and then study any potential relation between oral flora and foul-smelling dentures.

Cocktail effect

The analysis of samples extracted from the dentures provided a precise description of the oral microbiota. Results:  higher bacterial diversity in the foul-smelling samples (especially a higher abundance of bacteria known to release bad smell when decomposing) as well as significant difference in the microbial profile between the two groups. However, according to the literature, oral microbiota is composed of all bacterial subpopulations present in the different areas of the mouth. Consequently, it seems that bad breath is not due to a specific bacterium but instead results from some type of “cocktail effect” from all bacteria groups that colonize the mouth  and interact with one another. The researchers could not conclude whether these “foul-smelling” bacteria were associated to specific clinical symptoms or not. But they were able to confirm that proper dental hygiene could prevent denture malodour.



Yitzhaki S., Reshef L. ,Gophna U. et al - Microbiome associated with denture malodour – Journal of Breath Research 12 (2018) 027103.