Digital radiography is an updated version of X-ray imaging. Instead of using electromagnetic radiation and chemical processing to record an X-ray onto film, digital radiography uses digital X-ray sensors to record the X-ray onto an image capture device, which then creates a digital image file. This file can then be used by medical staff members to interpret the X-ray, and the file can be attached to a patient’s medical notes for future reference.

Two types of digital radiography are used. The first, known as indirect digital radiography, involves amorphous silicon (a-Si) flat panel detectors, and it works by converting X-ray images to light and channeling the image through an amorphous silicon photodiode layer that converts it to a digital signal. Thin film transistors (TFTs) then read this digital output, and it is turned into a data file that can be viewed by the X-ray technician. The technician checks that the X-ray is of a high quality and shows the desired body part clearly, then he or she forwards it to a radiologist for interpretation. This form of digital radiography is the most common and is used for most medical imagery.

The second type is direct digital radiography and involves amorphous selenium (a-Se) flat panel detectors. This uses a high-voltage electrode to accelerate X-ray photons through a selenium layer, and the pattern is then recorded. This creates an image file that is sent directly to the technician and on to the radiologist.

Digital dental radiography requires a slightly different process. Intraoral images are taken by asking the patient to bite down on an X-ray sensor placed inside the mouth. There is much less radiation involved in digital radiography, so it is safe enough to take numerous X-rays and view all of the teeth. This is useful for checking for decay or tooth problems that can be easily missed during a clinical checkup.

Extraoral images are created by placing the sensor outside the mouth, at the front of the head. This type of image typically shows all of the teeth from the tip to the root, and it is useful for identifying fractures or problems with the mandibular. It is less effective for spotting tooth decay or bone loss.