Test Overview

Dental X-rays are pictures of the teeth, bones, and soft tissues around them to help find problems with the teeth, mouth, and jaw. X-ray pictures can show cavities, hidden dental structures (such as wisdom teeth), and bone loss that cannot be seen during a visual examination. Dental X-rays may also be done as follow-up after dental treatments.

The following types of dental X-rays are commonly used. The X-rays use small amounts of radiation.

Bitewing.

These X-rays show the upper and lower back teeth in a single view. These X-rays are used to check for decay between the teeth and to show how well the upper and lower teeth line up. They also show bone loss when severe gum disease or a dental infection is present.

Periapical.

These X-rays show the entire tooth, from the exposed crown to the end of the root and the bones that support the tooth. These X-rays are used to find dental problems below the gum line or in the jaw, such as impacted teeth, abscesses, cysts, tumours, and bone changes linked to some diseases.

Occlusal.

These X-rays show the roof or floor of the mouth. They are used to find extra teeth, teeth that have not yet broken through the gums, jaw fractures, a cleft in the roof of the mouth (cleft palate), cysts, abscesses, or growths. Occlusal X-rays may also be used to find a foreign object.

Panoramic.

These X-rays show a broad view of the jaws, teeth, sinuses, nasal area, and temporomandibular (jaw) joints. They show problems such as impacted teeth, bone abnormalities, cysts, solid growths (tumours), infections, and fractures.

Digital.

These X-rays can be sent to a computer to be recorded and saved.

A full-mouth series of periapical X-rays (about 14 to 21 X-ray films) is most often done during a person's first visit to the dentist. Bitewing X-rays are used during checkups to look for tooth decay. Panoramic X-rays may be used now and then. Dental X-rays are scheduled when you need them based on your age, risk for disease, and signs of disease.

Why It Is Done

Dentists use X-rays to:

• Find problems in the mouth, such as cavities, dental injuries, and damage to the bones that support the teeth.
• Show teeth that are not growing in the right place or are too crowded to come out of the gums properly (impacted).
• Find cysts, tumours, or pockets of infection (abscesses) in the mouth.
• Check the location of permanent teeth in children who still have their baby teeth.
• Help plan treatments like doing a root canal, filling cavities, pulling teeth (extractions), or straightening teeth with braces. X-rays are also used for planning dental implants and dentures.

How To Prepare

In general, there's nothing you have to do before this test, unless your doctor tells you to.

How It Is Done

Dental X-rays are taken in the dentist's office.

• Your dentist will tell you if you need to take out any jewellery or piercings that may get in the way of the X-ray image.
• A dental technician will cover you with a heavy lead apron as you sit upright in a chair. This apron shields your body from X-rays. The technician can cover your neck with the collar of the apron (called a thyroid shield) to shield the thyroid gland from radiation.
• Everyone else in the room wears a protective apron or stays behind a protective shield.
• The dental technician will have you bite down on a small piece of cardboard or plastic. The cardboard or plastic holds X-ray film. You may do this several times to get pictures of all your teeth. Some X-ray machines have a camera that circles your head and takes pictures of your teeth while you sit or stand.
• You may want to rinse your mouth before and after the X-rays.

Some dentists use digital radiography. This method uses an electronic sensor instead of X-ray film. An electronic image is taken and stored in a computer. This image can be viewed on a computer screen. Less radiation is needed to make an image with digital radiography than with standard dental X-rays.

How long the test takes

The X-ray usually takes about a minute per image. You may get more than one image during a visit.

How It Feels

X-rays take only a few minutes and are not painful.

Some people may gag on the plastic or cardboard that holds the X-ray film. People often find it easier to relax if they focus on something else (such as an object on the wall) and take slow, deep breaths through their nose during the X-rays.

Risks

There is always a slight chance of damage to cells or tissue from radiation, including the low levels of radiation used for this test. But the chance of damage from the X-rays is extremely low. It is not a reason to avoid the test.

Dental X-rays are safe during pregnancy. So most dental work can be done while you are pregnant. Delaying dental care can make a problem worse. Your dentist will have you wear a lead apron over your belly to protect your baby from the X-rays.

Results

Your dentist can talk to you about your X-rays right after they are done.