To gain a better understanding of how sharks manage to keep their teeth in such pristine condition, a team of German researchers looked at two species that eat in very different ways

The researchers looked at Isurus oxyrinchus and Galeocerdo cuvier (mako and tiger sharks) and found, as they explain in their paper published in the Journal of Structural Biology, after very close examination, that the outer coating of the shark teeth contained one hundred percent fluoride.

Besides the hard crystal enamel structure that makes up the outside of the teeth, they found an inner organic dentin made of proteins which was more elastic, similar to that of human teeth. They note also the well known fact that sharks are able to replace teeth that are lost many times throughout their life cycle. The result they say, is a nearly perfect design, allowing sharks to rely on their teeth to keep them fed.