Spotting tooth decay could soon be as simple as pointing a tiny optical fibre at the tooth and letting a computer do the work. The technique, which is based on Raman spectroscopy, could spot tooth decay when it can still be stopped without any drilling and filling. It would also cut down on X-rays.
Raman spectroscopy detects chemical changes in a tooth by analysing how light is scattered when a laser is fired at it. In a preliminary study, researchers were able to tell healthy teeth from carious teeth because bacteria, responsible for the decay, scatter light in a different way to enamel and dentine. The preliminary results were unveiled at Microscience 2008.
The new technique would mean that dentists could simply shine a laser on a tooth to determine whether it was healthy or not. Frances Downey, a PhD student at Kings College, London, where the technique is being developed, said: ‘The earlier you spot decay the better. If you find it very early you can remineralise the area so there is no cavitation and so no need for a filling.’ Enamel is a highly crystalline material made up of over 90% calcium hydroxyapatite with the softer inner core of dentine containing around 50%.
Frederic Festy, who is supervising the project, says that the biomaterials, biomimetics and biophotonics research group is planning a larger trial using more teeth samples and hopes to move onto human trials soon. The key to the technique would be its simplicity, he explained. Festy says that they hope to have a marketable product in a little over five years.
Steven Hogg, a microbiologist at Newcastle University’s dental school, says if decay is caught early enough, it is possible to repair the tooth with a special mouthwash or fluoride varnish. Carious teeth are currently uncovered using visual examination and X-rays, but by then the damage is done and the decayed area must be drilled out and the tooth filled.
But there are still some problems to overcome before these machines make their way into the dental surgery. Raman spectrometers are costly, and scans take 30 seconds, a long time for any patient to remain perfectly still.