Commonly Used Dental X-Rays

Bitewing X-rays use the least amount of radiation and show the upper and lower back teeth in a single view. They are used to detect decay between the teeth and to show how well the upper and lower teeth line up. They also show bone loss that usually indicates the presence of severe gum disease or a dental infection.

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 detect dental problems below the gum line or in the jaw, including the presence of impacted teeth.

Occlusal X-rays show the roof or floor of the mouth and are used to detect the presence of 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 (such as a tumor). Occlusal X-rays may also be used to locate foreign objects.

Panoramic X-rays provide a broad view of the jaws, teeth, sinuses, nasal area, and temporomandibular (jaw) joints. These X-rays do not show the detail needed to detect cavities. These X-rays reveal problems such as impacted teeth, bone abnormalities, cysts, solid growths (tumors), infections, and fractures.

A full-mouth series of periapical X-rays, which may consist of 14 to 21 X-rays, are most often done during the first visit to the dentist. Bitewings are used during checkups to help the dentist diagnose tooth decay. Panoramic X-rays may be used periodically to screen for dental conditions. Like other aspects of your dental care, dental X-rays are scheduled on an individual basis and may vary with your age, risk for disease, and signs of disease.

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Do I Need Dental X-Rays?

Do I Need Them

I believe it is important to ask if you are unsure. We are prepared to discuss the risks and benefits associated with x-rays.

In our clinic we take x-rays based on clinical need versus a predetermined time interval. The protocol for x-rays has changed in recent years and we are current with these recommendations.

The need for radiographs is based on individual need each and every time a patient presents for examination. A number of factors are considered before x-rays are prescribed by Dr. Lunn.

X-rays can be an invaluable diagnostic tool that helps determine the appropriate treatment and likely outcome of the treatment. X-rays can show ill fitting fillings, decay not evident on visual examination, loss of supporting bone structure, tumor masses, and dental abscesses to name a few problems and reasons to take radiographs.

It is the very fact that there is some risk associated with a procedure that leads to the need for its selective use. However, discussing risks can be difficult. One way to discuss risk is to make legitimate comparisons. Effective dose is reported in sieverts and simply put allows us to compare diagnostic x-ray exposure to the exposure we receive through natural sources.

Discussing Risk

Using effective dose measurements, it is fair to compare chest x-rays (0.08mSv), to the bitewing series (0.017mSv), to the panoramic (0.007mSv). Or, we can say that a complete mouth series equals about five days of background radiation. A bitewing series equals 1 day and a panoramic is equal to 10 hours of background radiation.

Another approach is to relate the estimated risk of the x-ray examination to the estimated risks associated with other common activities. For example, one can compare the risk of developing a fatal cancer from dental x-ray examination to the risk of dying from some other activity. A complete full mouth series of radiographs results in a mortality risk estimate of 2.8 cases per one million examinations. By comparison, anyone that has smoked more than one cigarette has one in a million chance of dying of heart disease or cancer as a result of that indiscretion. We accept similar mortality risks every time we go on a 300 mile road trip, ride a bicycle 10 miles, or visit New York City for a weekend.

© Dr. Garry Lunn


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