Diagnodent is a diagnostic tool that helps us locate even the smallest amount of decay. Sometimes it is difficult to diagnose cavities, especially in the pits and grooves on the biting surfaces of your back teeth. The traditional way was to look for signs of decay on the tooth, checking x-rays, or feeling for a soft area with a dental explorer. Diagnodent uses a harmless pulse of laser light to check the grooves of the teeth. When a cavity is present, the wavelength of light being reflected back to the sensor is different. This is translated into a digital readout and number value. In general, the higher the number the greater the amount of decay in the tooth.