Laser ultrasound helps determine dental health

This is the first time anyone has employed such a tool to find the elasticity of our teeth, besides assessing dental health and predict tooth decay and cavities.
Enamel goes through a cycle of mineral loss and restoration, through a lifetime, in which healthy teeth maintain a high mineral content.
If the balance between mineral loss and gain is lost, however, teeth can develop areas of softened enamel -- known as carious lesions -- which are precursors to cavities and permanently damaged teeth.
"The ultimate goal is to come up with a quick, efficient, cost-effective, and non-destructive way to evaluate the mineralisation of human dental enamel," says study co-author David Hsiao-Chuan Wang, graduate student at the University of Sydney (U-S).

Wang and his adviser Simon Fleming, physics professor at the U-S Institute of Photonics and Optical Science, worked on the study with U-S dental researchers and ultrasonic researchers from National Cheng Kung University, Taiwan.
Stronger than bone, enamel is the hardest and the most mineralised substance of the human body -- one of the reasons why human teeth can survive for centuries after a person has died. It envelops teeth in a protective layer that shields the underlying dentin from decay, said an U-S release.
Enamel demineralisation is caused by bad oral hygiene. Not brushing, for instance, can lead to the build-up of dental plaques, and bacteria in these plaques will absorb sugars and other carbohydrates a person chews and produce acids that will dissolve the minerals in tooth enamel.
These findings were described in the latest issue of Optics Express, Optical Society's (OSA) open-access journal.