A dental x-ray is a picture of the teeth, surrounding bones and soft tissue that is taken using radiation.

Who is a candidate for the test?

People with oral diseases or injuries to the mouth, teeth or jaw usually require x-rays. X-rays are also used to screen healthy people for tooth decay and gum disease.

How is the test performed?

X-rays are usually taken in a dental office using a dental x-ray machine. This machine allows the dentist to position it for the best view of individual teeth and supporting bone. First, a soft dental film is placed inside the mouth. The x-ray machine is positioned outside the cheek to project the image of the teeth onto the film. The film is developed using special chemicals to reveal the black and white "negative" image.

New developments include digital radiography, in which the film is digitally processed. Other types of x-rays may require special machines and different procedures. These x-rays are used with orthodontics, or dentistry that focuses on crooked or badly aligned teeth. People who may need or have had surgery in their mouth may also need special types of dental x-rays.