It's been a mystery: how can our teeth withstand such an
enormous amount of pressure, over many years, when tooth enamel
is only about as strong as glass? A new study by Prof. Herzl
Chai of Tel Aviv University's School of Mechanical Engineering
and his colleagues at the National Institute of Standards and
Technology and George Washington University gives the answer.
The researchers applied varying degrees of mechanical pressure
to hundreds of extracted teeth, and studied what occurred on the
surface and deep inside them. The study, published in the May 5,
2009, issue of the Proceedings of the National Academy of
Sciences, shows that it is the highly-sophisticated structure of
our teeth that keeps them in one piece ― and that structure
holds promising clues for aerospace engineers as they build the
aircraft and space vehicles of the future. "Teeth are made from
an extremely sophisticated composite material which reacts in an
extraordinary way under pressure," says Prof. Chai. "Teeth
exhibit graded mechanical p