Dentics are a small, maggot-like creature found in the Uncharted Territories and the surrounding regions of space. Their initial planet of origin is unknown, but they have been spread by their frequent use by spacefarers. Dentics feed on bacteria and the small remnants of food left in someone's mouth -- making them ideal for keeping one's mouth clean and preventing gum disease. Because their urine has an aroma similar to that of mint, they leave mouths with a minty-fresh smell. As such, many sentient species began something of a symbiotic relationship with dentics.
Those using dentics must be careful not to accidentally swallow the creatures. They are inedible raw, and are sometimes even poisonous. They can be fried, however, and once cooked are safe to eat. Still, such fare is unpopular -- despite it's rather terrible taste, it also limits the supply of dentics available for actually cleaning teeth.
Use of dentics eventually spread even further, eventually reaching the Klingon Empire. It was not, however, popular with the vast majority of the United Federation of Planet's members or with the Romulan Star Empire.
Source[]
Dentics appear in Farscape.