Bite right

Sea urchins have teeth so powerful they can munch through limestone. These teeth are composed of calcite, a form of calcium carbonate, which happens to be the same material in the limestone they’re snacking on. So how do they chomp through the rock without grinding down their tusks? By aligning the calcite crystals that make up their teeth.

The structure and composition of the tip, particularly the orientation of the calcite crystals, is exquisitely controlled.

Maybe as dentists investigate how to spur humans to generate teeth like sharks, they can devise a way to make them as strong as those of a sea urchin. A scary prospect when you think about playing hockey.

• dentistry
• marinebiology
• science