Drills, X-rays, assorted sharp probes--these are the familiar, disquieting tools of dentists. Chris Longbottom, a dentist at the University of Dundee Dental School in Scotland, would like to add another item to that arsenal: electrodes that send electric currents through patients’ teeth and down their arms. To what end? Longbottom says the currents reveal incipient cavities that even X-rays might miss.
The process, Longbottom hastens to add, would be painless. Patients wouldn’t feel the tiny 10-millivolt current. The method takes advantage of the way cavities form. Bacteria in the mouth produce acids, which dissolve the minerals that make up teeth. This widens microscopic pores in teeth. Even before the pores widen into visible cavities, they decrease the electrical resistance of a tooth because the fluid in them is a better conductor than the solid tooth itself.
With special electrodes that fit over the places where teeth touch teeth, which are ...
