A Diagnodent uses a laser to scan the chewing surface of the
teeth. This laser contains several wavelengths of light, one of which is
fluorescent. Fluorescent light bounces off the cavity and goes back to the
sensor which then converts the data into a numeric readout. The higher the
number on the Diagnodent, the larger the amount of decay is present in the tooth. If the
Diagnodent laser finds an actual cavity it will emit an audible sound. The use
of this device enables the early detection of decay thus allowing for more
conservative restorations.