The mere mention of X-rays causes people to cringe in their dental chairs.  With the increased national incidence of cancer, the fear of radiation is understandable.  Therefore, it is important to know how much radiation is received from a dental X-ray, how harmful the effects are, and why they are necessary. 

What is an X-ray?  X-rays are wavelength forms of energy (similar to light) which have the ability to go through your body.  These wavelengths can be measured units called millirems (mrem).  Each dental X-ray requires approximately 2 mrem.  The newest technology of digital X-rays is approximately 0.22 mrem/X-ray.  According to the National Council on Radiation Protection (NCRP), the average U.S. resident receives 360 mrem every year from just background sources.  Some specific examples of background sources include:  smoke detectors (1 mrem/year), cooking with natural gas (6 mrem/year), and flying in an airplane cross country (3 mrem/trip). 

The National Academy of Sciences recently released a report stating that “the health risk posed from X-rays is so small that is should not deter people from seeking needed care.”  To give an example of high risk radiation, a two pack cigarette per day person acquires 8,000 mrem exposure per year.

Dentists use an X-ray to detect tooth decay, infections, signs of gum disease, changes in jaw bones, and the overall composition of your facial structures and bones.  The interpretation of X-rays allows a dentist to safely and accurately detect decay and infection that may not be apparent through visual examination.  If decay and pathology are detected early, the tooth may be treated more conservatively.  In other words, small cavities require small fillings and restorations, and large cavities may lead to crowns and the dreaded root canal. 

Frequency of X-rays taken depends on the health needs of the patient.  It is important to note that each patient is different from the next.  Dentists are trained to review one’s medical history and examine one’s mouth to determine whether X-rays are needed and what type. 

Dentists use guidelines (set by the American Dental Association) when determining the frequency and type of X-rays to be taken for a patient.  These guidelines vary according to signs and symptoms, age, and risk for disease.

For any questions, comments, or concerns, you may contact Rashmi (Rush) Bhatnagar, DMD, MPH at (480) 598-5900 or visit


Dr. Rashmi (Rush) Bhatnagar, DMD, MPH, can be contact at (480) 598-5900 or visit


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