- The outside of shark teeth is made up of fluoride, the active component of most toothpaste.
- Although human teeth are covered in a different mineral, both shark and human teeth are equally hard.
- Sharks never get cavities, and are able to replace their teeth multiple times throughout their lives.
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,
While shark teeth contain the mineral fluoroapatite (fluorinated calcium phosphate), the teeth of humans and other mammals contain hydroxyapatite, which is an inorganic constituent also found in bone, explained co-author Matthias Epple.
"In order to make teeth more acid resistant, toothpaste often contains fluoride," Epple, a professor of inorganic chemistry at the University of Duisburg-Essen, told Discovery News. "In the surface of human teeth after brushing, a small amount -- much less than 1 percent -- of hydroxide is exchanged by fluoride."