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.