Shark teeth have built-in toothpaste
Baku, July 27 (AZERTAC). 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.”
“In contrast,” he added, “(the surface of) shark teeth contains 100 percent fluoride. In principle, sharks should not suffer from caries. As they live in water and as they change their teeth regularly, dental protection should not be a problem for sharks.”
For the study, Epple and colleagues Joachim Enax, Oleg Prymak and Dierk Raabe used a multitude of high tech investigative techniques, including scanning electron micrographs, to look at the teeth of two different sharks: the shortfin mako (Isurus oxyrinchus) and the tiger shark (Galeocerdo cuvier). These sharks were chosen because of their different eating habits. Shortfin makos tear the flesh of prey, while tiger sharks cut flesh.
Other news in this section
