Laser tests may replace dentists drill

The dentists dreaded drill may soon be a thing of past, thanks to the laser tests University of Sydney scientists have developed to identify weakness in dental enamel. Currently, X-rays and metal probes are used to check cavities, but they fail to detect weakness in the enamel in time to repair the surface. Lead researcher David Wang sought to determine whether the propagation of sound waves through the enamel could provide an early warning. The study showed that short, low-energy pulses from a laser generate weak bursts of acoustic waves in the surface of the enamel. In tests on an extracted tooth, Wang detected these vibrations by collecting infrared laser light reflected from the surface of the tooth. He found that changes in mineralization of the enamel, which signal the onset of decay, appear to cause in the pattern of acoustic waves.