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 X-rays show the upper and lower back
teeth and how the teeth touch each other 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 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, tumors, and bone changes linked to some
diseases.
- Occlusal X-rays show the roof or floor of the mouth and
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 X-rays show a broad view of the jaws, teeth,
sinuses, nasal area, and temporomandibular (jaw) joints. These X-rays do not
find cavities. These X-rays do show problems such as impacted teeth, bone
abnormalities, cysts, solid growths (tumors), infections, and
fractures.
- Digital 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 occasionally. Dental X-rays are scheduled when you need them
based on your age, risk for disease, and signs of disease.
Why It Is Done
Dental X-rays are done to:
- Find problems in the mouth such as tooth
decay, damage to the bones supporting the teeth, and dental injuries (such as
broken tooth roots). Dental X-rays are often done to find these problems early,
before any symptoms are present.
- Find teeth that are not in the
right place or do not break through the gum properly. Teeth that are too
crowded to break through the gums are called impacted.
- Find cysts,
solid growths (tumors), or abscesses.
- Check for the location of
permanent teeth growing in the jaw in children who still have their primary (or
baby) teeth.
- Plan treatment for large or extensive
cavities,
root canal surgery, placement of dental implants, and
difficult tooth removals.
- Plan treatment of teeth that are not
lined up straight (orthodontic treatment).
Without X-rays, dentists may miss the early stages of decay
between teeth.
For people
who have no tooth decay and are not at high risk of getting cavities:1
- Adults should have bitewing X-rays every 2
to 3 years.
- Teens should have bitewing X-rays every 1½ to 3
years.
- Children should have bitewing X-rays every 1 to 2
years.
For people who
have tooth decay or are at high risk of getting cavities:1
- Adults should have bitewing X-rays every 6 months to 1½ years.
- Children and teens should have bitewing X-rays every 6 to 12 months.
How To Prepare
Before the X-ray test, tell your
doctor if you are or might be pregnant. Dental X-rays are only done on your
mouth area, but if you are pregnant, routine dental X-rays may be postponed so
you do not have any radiation to your baby (fetus). If
dental X-rays are absolutely needed, a lead apron will be placed over your
belly to shield your baby from the X-rays.
You do not need to do
anything else before having a dental X-ray.
How It Is Done
Dental X-rays are taken in the
dentist's office. The X-ray pictures are read by your
dentist.
- 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 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
The amount of radiation used in dental X-rays is low. But there is always a slight risk of damage to cells or tissue from being exposed to any radiation, including the low levels of radiation used for this test. But the risk of damage from the X-rays is usually very low compared with the potential benefits of the test.
Pregnant women may not want to have routine dental X-rays taken until after
they give birth. Although there is no proof that a routine dental X-ray could
harm a developing baby (fetus), dentists usually suggest you wait to have your
X-rays until after the baby is born. Delaying the X-ray for a few months will
not result in further harm to teeth in most cases. There are times when the
severity of the dental problem requires an X-ray to deal with an urgent
concern.
Results
Dental
X-rays are pictures of the teeth, bones, and soft
tissues around them to help find problems with the teeth, mouth, and jaw. Your
dentist can talk to you about your X-rays right after they are done.
Dental X-raysNormal: | No tooth decay is
seen. |
|---|
No damage to the bones
supporting the teeth is seen. |
No dental injuries, such as
tooth or jaw
fractures, are seen. |
No
cysts, solid growths (tumors), or
abscesses are seen. |
No extra or
impacted teeth are seen and no teeth are out of their
normal place. |
Abnormal: | Tooth decay is
seen. |
|---|
Damage to the bones supporting
the teeth is seen. |
Dental injuries, such as tooth
or jaw fractures, are seen. |
Cysts, solid growths
(tumors), or abscesses are seen. |
Abnormally placed, extra, or
impacted teeth are seen. |
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- If you can't stay still or hold the X-ray
plastic or cardboard in your teeth.
- If you have braces, retainers,
dentures, bridges, and certain body piercings (ear, tongue, lip, cheek, or
nose).
What To Think About
If you are going to a new dentist, have
your other dentist send copies of your dental X-rays to your new dentist. You
may not need any more X-rays with your new dentist.
References
Citations
- American Dental Association Council on Scientific Affairs (2006). The use of dental radiographs: Update and recommendations. Journal of the American Dental Association, 137(9): 1304–1312.
Other Works Consulted
- American Dental Association Council on Scientific Affairs (2006). The use of dental radiographs: Update and recommendations. Journal of the American Dental Association, 137(9): 1304–1312.
- Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
Credits
| By | Healthwise Staff |
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| Primary Medical Reviewer | Patrice Burgess, MD - Family Medicine |
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| Specialist Medical Reviewer | Steven K. Patterson, BS, DDS, MPH - Dentistry |
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| Last Revised | June 13, 2012 |
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