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When and why to get dental X-rays?

Published:Monday | October 13, 2014 | 10:00 AM

Dental x-rays help dentists visualise diseases of the teeth and surrounding tissue that cannot be seen with a simple oral exam. In addition, X-rays help the dentist find and treat dental problems early in their development, which can potentially save you money, unnecessary discomfort, and maybe even your life.

See Figure 1 where development of extra teeth (supernumerary teeth) would have gone unnoticed had the X-ray not been taken. Decay, and more serious conditions like cysts, metastases (cancer from other areas), genetic conditions, and other pathology are frequently missed when X-rays are not done. Missing pathology may have serious consequences long term, not excluding tooth loss.

What Problems Can Dental X-Rays Detect?

In adults, dental X-rays can be used to:

Show areas of decay that may not be visible with an oral exam, 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 an abscess (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 tumours.

In children, dental X-rays 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 come in properly.

Check for the development of wisdom teeth and identify if the teeth are impacted (unable to emerge through the gums).

Are Dental X-rays Safe?

Dental X-rays are safe, however, they do require very low levels of radiation exposure, which makes the risk of potentially harmful effects very small, especially if your dentist is using digital X-rays. Dental X-ray tools and techniques are designed to limit the body's exposure to radiation, and every precaution is taken to ensure that radiation exposure is As Low As Reasonably Achievable (the ALARA principle).

A leaded apron minimises exposure to the abdomen and may be used when it will not interfere with acquisition of the dental radiograph. Also, a leaded thyroid collar can protect the thyroid from radiation, and should also be used whenever possible. The use of a leaded thyroid collar is recommended for women of childbearing age, pregnant women, and children.

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 because of 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. However, please remember that a proper screening and diagnosis, requires X-rays.

Are you pregnant? Make sure to tell your dentist. During your pregnancy, you may need to have X-rays taken as part of your treatment plan for a dental disease. Use of the leaded apron and thyroid collar will protect you and your foetus from radiation exposure. However, it is recommended that your dentist consult with your physician when taking X-rays while pregnant. Dental X-rays do not need to be delayed if you are trying to become pregnant or are breastfeeding.

How Often Should Teeth Be X-Rayed?

The frequency of getting X-rays of your teeth 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 exam 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:

Dental X-Ray Schedule for Children, Adolescents, and Adults

New patients repeat patient, high risk (decay is present) Repeat patient, no decay, not at high risk for decay Current or history of gum disease Other comments

Children (before eruption of first permanent tooth) x-rays if the teeth are touching and all surfaces cannot be visualised or probed x-rays taken every six months until no decay is present x-rays taken every 12 to 24 months if the teeth are touching and all surfaces cannot be visualised or probed x-rays of areas where disease is seen in the mouth x-rays to check for growth and development are usually not indicated at this age

Adolescents (before eruption of wisdom teeth) A full series of x-rays is indicated when there is evidence of dental disease or history of extensive decay. X-rays taken every 6 to 12 months until no decay is present X-rays taken every 18 to 36 months x-rays of areas where disease is seen in the mouth x-rays should be taken to check for development of wisdom teeth

Adults with teeth A full series of x-rays is indicated when there is evidence of dental disease or history of extensive decay. X-rays taken every 12 to 18 months x-rays taken every 24 to 36 months x-rays of areas where disease is seen in the mouth x-rays to check for growth and development are usually not indicated.

Adults without teeth X-rays are usually not indicated unless specific dental disease is clinically present.

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

o Children. Children generally need more x-rays than adults because their teeth and jaws are still developing and because their teeth are smaller. As a result, decay can reach the inner part of the tooth, dentin, quicker and spread faster.

o Adults with extensive restorative work, such as fillings to look for decay beneath existing fillings or in new locations.

o 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).

o People with periodontal (gum) disease to monitor bone loss.

o People who have dry mouth - called xerostomia - whether due to medications (such as antidepressants, anti-anxiety drugs, antihistamines, and others) or disease states (such as Sjsgren's syndrome, damaged salivary glands, radiation treatment to head and neck). Dry mouth conditions can lead to the development of cavities.

o Smokers to monitor bone loss resulting from periodontal disease (smokers are at increased risk of periodontal disease).

Contributed by Dr Anna Law - Align Orthodontics.

If you have more questions about x-rays, please ask your dentist or email Dr Anna Law at info@bracesbydrlaw.com.