Human Teeth as Strong as Those of Tiger Sharks

by Kathy Jones on Aug 3 2012 8:36 PM

 Human Teeth as Strong as Those of Tiger Sharks
A new study conducted by a team of German researchers has found that human teeth are smaller in size and number, their strength is comparable to those of a tiger shark.
Scientists made the surprising find after comparing the micro-structure of human and shark teeth.

They found that despite the teeth of the top ocean predator being coated with super-tough enamel, they are no stronger than the teeth found in human beings.

"This is due to the special micro and nanostructure of our teeth," the Daily Mail quoted lead researcher Professor Matthias Epple, from the University of Duisburg-Essen in Germany, as saying.

"The crystals in human teeth have a special arrangement and they are 'glued together' by proteins which stop cracks from running through the whole tooth," he said.

Shark teeth have an interior of elastic dentin and an outer layer of hard enamel toughened by the fluorine-based mineral fluoroapatite.

Human enamel is softer, consisting of the mineral hydroxyapatite, which is also present in bones.

But because of their structure, the overall strength of human teeth was on a par with that of the shark, the scientists found.

The research, published in the Journal of Structural Biology, could aid the design of stronger and longer lasting dentures.

"It would be great if, sometime in the future, one could repair teeth with a material which is more natural than today's provisional solutions," said Prof Epple.

He added that when it came to teeth, sharks still had the edge over humans.

Shark teeth are replaced continuously and, unlike those of a human, never develop cavities.

"The reason might be the fluoroapatite and the revolving set of teeth which is always immersed in sea water," said Prof Epple.

"And, finally, sharks do not eat sugar," he added.