In adults, X-ray films can be used to:

• Show areas of decay that may not be visible with an oral examination, especially small areas of decay between teeth
• Identify decay occurring beneath an existing filling
• Reveal bone loss that accompanies gum disease
• Reveal changes in the bone or in the root canal resulting from infection
• Assist in the preparation of tooth implants, braces, dentures, or other dental procedures
• Reveal abscesses (an infection at the root of a tooth or between the gum and a tooth)
• Reveal other developmental abnormalities, such as cysts and some types of tumors

In children, dental X-ray films are used to:

• Watch for decay
• Determine if there is enough space in the mouth to fit all incoming teeth
• Determine if primary teeth are being lost quickly enough to allow permanent teeth to erupt properly
• Check for the development of wisdom teeth and identify if the teeth are impacted (unable to emerge through the gums)

The frequency of getting X-rays often depends on your medical and dental history and current condition. Some people may need X-rays as often as every six months; others with no recent dental or gum disease and who visit their dentist regularly may get X-rays only every couple of years. If you are a new patient, your dentist may take X-rays as part of the initial examination and to establish a baseline record from which to compare changes that may occur over time.

Some general guidelines your dentist may follow regarding the frequency of dental X-rays is as follows:

People who fall into the high risk category who may need X-ray films taken more frequently include:

• Children. Children generally need more X-rays than adults because their teeth and jaws are still developing and because their teeth are more likely to be affected by tooth decay.
• Adults with extensive restorative work, such as fillings to look for decay beneath existing fillings or in new locations.
• People who drink a lot of sugary beverages to look for tooth decay (since the sugary environment creates a perfect situation for cavities to develop).
• People with periodontal (gum) disease to monitor bone loss.
• People who have dry mouth whether due to medications (such as antidepressants, antianxiety drugs, antihistamines, and others) or disease states (such as Sjogren's syndrome, damaged salivary glands, radiation treatment to head and neck). Dry mouth conditions can lead to the development of cavities.
• Smokers to monitor bone loss resulting from periodontal disease (smokers are at increased risk of periodontal disease).

Exposure to all sources of radiation -- including the sun, minerals in the soil, appliances in your home, and dental X-rays -- can damage the body's tissues and cells and can lead to the development of cancer in some instances. Fortunately, the dose of radiation you are exposed to during the taking of dental X-rays is extremely small.

Advances in dentistry over the years have lead to a number of measures that will minimize the risks associated with X-rays. However, even with the advancements in safety, the effects of radiation are added together over a lifetime. So every little bit of radiation you receive from all sources counts.

If you are concerned about radiation exposure due to X-rays, talk to your dentist about how often X-rays are needed and why they are being taken. While some people need X-rays taken more frequently, current guidelines require that X-rays be given only when needed for clinical diagnosis.

Reviewed by the doctors at The Cleveland Clinic Department of Dentistry.

Reviewed by Jay H. Rosoff, DDS, on March 1, 2007

Edited by Charlotte E. Grayson Mathis, MD, on May 1, 2005

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