No Cavities for Sharks.
Shark Teeth Have Built in Toothpaste Their dense, flat, crushing teeth contain fluoride keeping their impressive mouths free of cavities and other dental problems. An in-depth look at shark teeth has found that they contain fluoride, the active ingredient of most toothpaste and dental care mouthwashes.
It helps to explain why sharks are so effective at either tearing or cutting prey. Their teeth are perfectly designed for such tasks, never suffering from cavities, according to the study, recently published in the Journal of Structural Biology,