Tooth enamel holds clues to future aircraft design

A new study has shown that the sophisticated structure of tooth enamel holds clues for aerospace engineers as they build the aircraft and space vehicles of the future.

Professor Herzl Chai of Tel Aviv University’s School of Mechanical Engineering and his colleagues at the George Washington University applied varying degrees of mechanical pressure to hundreds of extracted teeth, and studied what occurred on the surface and deep inside them.

Professor Chai said: ‘Teeth are made from an extremely sophisticated composite material which reacts in an extraordinary way under pressure.

‘Teeth exhibit graded mechanical properties and a cathedral-like geometry, and over time they develop a network of micro-cracks which help diffuse stress. This, and the tooth’s built-in ability to heal the micro-cracks over time, prevents it from fracturing into large pieces when we eat hard food, like nuts.’

Chai, himself an aerospace engineer, suggests that if engineers can incorporate tooth enamel’s wavy hierarchy, micro-cracking mechanism, and capacity to heal, lighter and stronger aircraft and space vehicles can be developed.

As Chai puts it, tooth fractures ‘have a hard time deciding which way to go,’ making the tooth more resistant to cracking apart. Harnessing this property could lead to a new generation of much stronger composites for planes.

And while creating a self-healing airplane is far in the future, this significant research on the composite structure of teeth can already begin to inspire aerospace engineers – and, of course, dentists.

Dental specialists can use this basic research to ‘create smart materials that mimic the properties found in real teeth,’ Chai said. This could help invent stronger crowns, better able to withstand oral wear-and-tear.

These findings were published in the Proceedings of the National Academy of Science.