Tooth decay gets an electric charge

Dentists could soon dispense with potentially harmful x-rays to detect tooth decay if they adopt an electrical technique devised by scientists in Scotland.

Tooth decay could soon be detected without resorting to potentially harmful X-rays – by using a novel electrical technique developed by dental researchers at the University of Dundee in an unusual partnership with textile experts at Heriot Watt University.

Laboratory tests show the device, which measures the electrical resistance of teeth, is twice as accurate as current examination techniques and detects decay in its earliest stages when preventive treatment is still possible.

Known as ACIST (AC impedance spectroscopy technique) the device has been developed by the Dundee team together with colleagues in St Andrews University. The sensor, which was patented in 1996, is being developed in collaboration with textile specialists at Heriot Watt University.

The concept reportedly exploits the change in the nature of the tooth as it decays. As caries progress microscopic pores develop in the tooth, which fill with fluid that conducts current. By applying an electrically conductive strip to the tooth and passing a small electrical current through it, dentists can use the amount of resistance to the charge as a gauge of whether there is any decay.

‘The technique is expected to be faster, safer and more accurate than X-rays which is good news for patients, dentists and the health service where it has cost-saving implications,’ said principal investigator Dr Chris Longbottom. ‘By picking up the disease at an early stage it will also be possible in many cases to stop or even to reverse the decay thus saving more teeth.’

The plastic sensor used to measure the electrical resistance is being developed by Heriot Watt`s school of textiles in Galashiels who are working on a special polymer that could be inserted between the teeth like a wider type of dental floss.

The information from the sensor is fed to the electrical device and could be used by dentists instead of a traditional X-ray.

Once complete the probe will be clinically tested and assessed by dental researchers and, if successful, it could be taken to the commercial stage.

The Dundee and Heriot Watt teams learned yesterday they have been awarded £139,500 funding by Scottish Enterprise through the Proof of Concept Fund, to develop a prototype probe for testing. If successful it could be in the market place in two years.