Dental x-rays could be a thing of the past thanks to a new technique that has been developed by pioneering research firm IDMoS.

Based on AC impedance spectroscopy, the company's new IDMoS CarieScan has the capability to detect tooth decay with higher levels of accuracy and certainty than existing techniques and without the safety risks associated with the repeated use of x-rays.

The new system is based on the premise that changes in the physical structure of a tooth can be directly related to its electrical behaviour.

It works by applying a small alternating current through a tooth while monitoring its impedance. By changing the frequency of the applied signal, a spectrum of impedance points can be built and displayed in a plot that is unique to the sample under investigation. Since an impedance plot of a tooth with sound enamel differs from a tooth with decayed enamel, a dentist can hence determine where fillings are required.

Because the technique relies on making impedance measurements, it has no effect on the sample being measured, and is, therefore, particularly suitable for medical applications.

To verify the system, a team of scientists from the University of Abertay Dundeeā€™s SIMBIOS (Scottish Informatics and Mathematics Biology and Statistics) Centre are using sophisticated CAT (Computerised Axial Tomography) scanning equipment.

'Our role will be to verify that this new technology works by using CAT scans to check sample teeth for cavities and decay,' said Prof Iain Young, the university's Chair of the Environmental Sciences School.