Dental radiographs, or X-rays, are an important part of a thorough dental examination. A full set of X-rays (18) is usually required for patients who are new to a dental practice, or who need extensive treatment. Two to four follow-up or check-up X-rays called "bite-wings" are necessary every 6-18 months, depending on each individual patient’s needs. The most common questions concerning dental X-rays deal with: why they are needed, the amount of radiation exposure, the safety during pregnancy, and recently, the benefit of digital X-ray technology.
Dental X-rays are important for many reasons. They can expose hidden tooth decay; reveal a tooth abscess, cyst or tumor; show impacted or extra teeth; and also help determine the condition of dental fillings, tooth crowns, dental bridges and root canals. Dental X-rays can also reveal bone loss from periodontal gum disease, locate tarter buildup, find foreign bodies within the gum or bone, and see if there is enough bone for the placement of dental implants. These are just some of the many reasons why dentists rely on dental X-rays.
Some people worry about their exposure to radiation during dental X-ray procedures. This is very understandable in light of the relatively high radiation of some medical X-rays. They may remember a doctor in the emergency room asking them or a female family member if they are pregnant because they need to take a chest X-ray or an upper gastrointestinal (GI) series. Patients who have had cancer may also have a heightened sense of awareness about the radiation that they are receiving at the dental office.
Dentists are very concerned about minimizing the amount of radiation a patient receives at the dental office. That’s why we use special high-speed film, and cover patients with a lead apron during X-ray procedures. You will be happy to know that 18 dental X-rays deliver 56,000 times less radiation to an unborn child than an upper GI series, 800 times less radiation than a chest X-ray, and 40 times less radiation than a typical day of background radiation. Dental X-rays are both safe and effective, and can be used during pregnancy.
One new dental technology involving dental X-rays is digital X-rays. They offer the advantage of an 80 percent reduction in radiation, no need for film or processing chemicals, production of a nearly instantaneously image, and the ability to use color contrast in the image. The main disadvantage is the cost. Digital X-ray units presently cost 3-5 times more than conventional units, and the quality of the image is not any better than film. The speed in which a dentist gets to see the image is about three seconds, but with fast developing chemicals, a conventional X-ray can be developed in about 15 seconds. The digital unit does reduce exposure to radiation, but the amount of radiation is so low that the benefit is very slight.
Dental X-rays are an important tool in the diagnosis and treatment of dental problems. They do not, however, replace the need for a visual examination of the head, neck, TMJ and oral cavity. It is only with a combination of both the X-ray and the visual examination that the dentist can best treat his or her patients.