But studies show that about 80% of bad breath comes from an oral source. For instance, cavities or gum disease can lead to bad breath, as can tonsils that have trapped food particles; cracked fillings, and less-than-clean dentures.

How do you get rid of bad breath from a cavity?

Can you smell a cavity?

All joking aside, the bacteria in decay gives off a very unpleasant smell. When a cavity has formed, this build up of bacteria in your mouth can cause your teeth and breath to smell bad. People who have untreated periodontal disease can also experience bad breath.