Why Sharks Never Get Cavities

27.07.2012

Shark teeth are covered with fluorideTeeth are sharks' main weapon for hunting and protection. Humans have an option to go to dentistry, but for sharks losing teeth for cavities means death. Nature is the best doctor though: German scientists found out that sharks would never have dental caries, because their teeth are covered with fluoride, a mineral substance that isd traditionally added to most toothpastes.

Human dental enamel mainly consists of hydroxylapatite, or calcium apatite. We obtain fluorides that protect teeth from toothpaste. After we brush our teeth, about 1% of hydroxylapatite is replaced by fluoride. German researchers figured out that sharks' teeth consist of fluorapatite, natural mineral that already contains fluorine and protects teeth from cavities. Besides, it is less water-soluble than human hydroxylapatite, that is why sharks' teeth are more stable and caries-proof. However, despite the fact that fluorapatite is harder than hydroxylapatite, it is less durable. The reason for it, scientists suppose, is in specific crystal structure of the enamel and in protein molecules that stabilize it.

Besides that, if shark loses a tooth, it is quickly replaced by a new one.