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Radiation

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How Much Radiation Do You Get from Dental X-Rays?
©Tyler Olson/Shutterstock.com

In order for dentists to see hidden problems in your jaws and in your teeth, it is necessary to take x-rays.  It goes without saying that the more dental x-rays you get, the more radiation exposure your body receives.  Extensive exposure to radiation can increase your risk of getting certain types of cancer — this is why it is important to only get needed dental x-rays.

How many dental x-rays you need and how often you need them largely depends on your risk for oral disease.  You can find out how often you should get dental x-rays taken here.

The purpose of this article is to simply let you know how much radiation various types of dental x-rays give you.

Radiation from Dental X-Rays

Radiation from Dental X-RaysRadiation is measured in units called Sieverts, named after Rolf Sievert, a highly-regarded medical physicist known for his work on measuring radiation dosage.  It is estimated that people living in the United States receive 3 milli sieverts of radiation per year from background radiation sources.

The radiation dose received from dental x-rays is measured in micro sieverts.  To help you relate the following numbers to your life, the background radiation that someone living in the United States receives per day is around 9 micro sieverts.

Radiation from Routine Dental X-Rays

A regular dental x-ray, like the one being taken in the picture above, exposes the patient to roughly 10 micro sieverts of radiation.  If the dentist is using an old-style dental film, then more radiation is needed and that number can climb to around 22 micro sieverts.  If the dentist is using a newer-style of x-ray unit that has a rectangular end instead of the round end (as is pictured above), then the radiation dose decreases drastically to around 2 to 5 micro sieverts.

If you get a full mouth series of dental x-rays (usually 18 x-rays), then you’ll be exposed to around 180 micro sieverts of radiation.

Radiation from Panoramic Dental X-Rays

A panoramic or panorex dental x-ray exposes the patient to anywhere from 9 to 26 micro sieverts of radiation.

If you went in to your dentist for a visit and they took four routine dental x-rays along with a panoramic x-ray, you would end up getting about 50-60 micro sieverts of radiation, or the equivalent amount of radiation exposure that you get from living on this earth for 6 days.

Radiation from a Lateral Cephalometric Dental X-Ray

Many adolescents get lateral cephalometric (or lateral ceph) x-rays when they get braces.  A lateral cephalometric x-ray exposes the patient to around 5 micro sieverts of radiation, or the equivalent of 1/2 day of background radiation exposure.

Radiation from a Cone Beam CT Dental X-Ray

Cone beam CT scans can be used to visualize the jaw bones in three dimensions. This aids dentists in diagnosing fractures and oral pathology and can also aid in evaluating patients to receive dental implants.

Depending on the brand of the cone beam CT unit, they emit anywhere from 20 to 600 micro sieverts of radiation, or the equivalent of 3 to 75 days of background radiation.

Questions about Radiation from Dental X-Rays?

For the record, I got the numbers above from the textbook Oral Radiology by White.

Do you have any questions, comments, or concerns about the amount of radiation that you get from dental x-rays? I’d love to hear what you have to say in the comments section below.

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How Often You Should Get Dental X-Rays Taken
©Tyler Olson/Shutterstock.com

I’ve gotten a few emails lately asking about how often dental x-rays should be taken.  An extreme example involved a young girl who had nearly 50 x-rays taken of one tooth over the course of a few years.

Another common example involves an adult who has never had a cavity.  Her dentist wants to take x-rays of her teeth every year.

Dental Panoramic X-RayThe main problem with getting so many x-rays is that whenever your body gets exposed to radiation, there is a risk of damaging your DNA, which could lead to cancer.  The amount of radiation from x-rays is very small, so this isn’t something to worry about, but getting lots of dental x-rays every year can add up to a lot of radiation exposure over your whole life!

Do people really need to have x-rays taken this often?  Let’s find out below!

How Often You Should Have Dental X-Rays Taken

The answer really depends on your oral health and your age.  For example, a 35-year old woman who has never had a cavity would require x-rays less often than than an 8-year old boy who has had several cavities in the past and doesn’t brush his teeth.

In order to provide the best answer to the question of how often to have x-rays taken, I will break it down into five different answers based on age and oral health.  Hopefully you can identify the category that  most closely resembles your situation to get a general idea of how often you need to have dental x-rays taken.

One more note: To figure out whether you fall into the low cavity risk or high cavity risk category, think about how many cavities you’ve had in the past, whether you’ve had any recent cavities, the amount of sugar you eat or drink, and whether or not you brush and floss daily.  People with previous cavities and poor oral hygiene are usually at a higher risk for getting cavities and would need to have x-rays taken more often.

How Often www.health-canada-pharmacy.com Does a Child (Under 18) with a High Cavity Risk Need Dental X-Rays?

A child with cavities or at a high risk for getting cavities would generally need dental x-rays taken every 6 to 12 months.

If there are spaces between your child’s teeth and the dentist can clinically inspect those teeth, then x-rays are generally not necessary.  It is always important to weigh the benefits and risks of having x-rays taken.

How Often Does an Adult (Over 18) with a High Cavity Risk Need Dental X-Rays?

An adult with frequent cavities or at a high risk of getting cavities would need dental x-rays taken every 6 to 18 months.

How Often Does a Child (Under 12) with a Low Cavity Risk Need Dental X-Rays?

A child younger than 12 years old with no current cavities and at a low risk of getting cavities would need dental x-rays taken every 12 to 24 months.  Again, many children have spaces between their teeth.  If this is the case, the dentist can usually detect cavities simply by looking in the mouth and would not need to take x-rays on those teeth.

How Often Does a Teenager (12-18) with a Low Cavity Risk Need Dental X-Rays?

A teenager with no current cavities and at a low risk of getting cavities would need dental x-rays taken every 18 to 36 months.

How Often Does an Adult (Over 18) with a Low Cavity Risk Need Dental X-Rays?

An adult with no current cavities and at a low risk of getting cavities would need dental x-rays taken every 24 to 36 months.

Other Scenarios Where Dental X-Rays May Be Necessary

The scenarios above are mainly to diagnose cavities and refer to the routine bitewing radiographs that dentists take.  There are many other situations when a dentist would want to take different x-rays where I couldn’t find clear guidelines, such as for monitoring periodontal disease, monitoring teeth that are at an increased risk for developing disease, and for monitoring growth in adolescents.

However the situation that I described above in which a young girl had nearly 50 x-rays taken on one tooth over a few years is definitely too many!

At my dental school, we used the book Treatment Planning in Dentistry by Stefanac and Nesbitt to learn about when and how often to prescribe dental x-rays.  I am basing the recommendations for the timing of dental x-rays found above on information found in that textbook, which coincide with the recommendations from the American Dental Association (PDF).

Conclusion

As you can see, dentists may recommend x-rays for diagnosing cavities anywhere from every six months to every three years — depending on your oral health.

Keep in mind that the above guidelines are just that — guidelines.  You may need x-rays taken more or less often depending on what you and your dentist think is best for you.  For example, if you have spaces between all of your teeth and the dentist can see whether or not you have cavities just by looking in your mouth, then there probably isn’t a need for dental x-rays.

Do you have any questions or comments on the timing of dental x-rays?  I’d love to hear what you have to say in the comments section below.  Thanks for reading!