We are frequently asked if dental X-Rays are an absolute necessity, and whether or not there are inherent risks associated with the ionizing radiation produced by modern X-Ray technology. As caregivers of children, including myself, we understand your concerns and respect your efforts to stay informed about issues related to your child’s health. By understanding the medical reasoning about when and why we take X-Rays and by having some knowledge about X-Ray exposure and perceived risks, you will be in a better position to make an informed decision on what’s best for your child.
Dental X-Rays are a critical tool in diagnosing cavities in teeth, particularly the most common type that occurs between the teeth. According to the 2000 U.S. Surgeon General Report, almost half of all kindergarteners have cavities. In 2006, it was found that 71% of California children have suffered from cavities by the time they are in 3rd grade. Cavities that are between the teeth are generally invisible to a visual inspection until they are very large and close to, or even into, the nerve. If we can diagnose decay at an early stage using X-Rays, it allows us to place a more conservative filling which is easier for your child to tolerate and which requires us to drill out less tooth structure. Alternatively, by waiting until the decay is large enough to be visible, we are likely to need more substantial treatment that may include a root canal, a stainless steel crown, or in the worst case, the removal of an abscessed and painful tooth. Since, on average, your child is likely to retain his or her back baby teeth until 10-12 years old, appropriate treatment at an early age will prevent pain and infection.
Our practice and green philosophy is to always act in the best interests of our patients and in many cases that may mean monitoring rather than aggressive treatment. The same green philosophy applies to X-Rays. Our doctors will never prescribe an X-Ray unless we believe it’s clinically necessary and we will always personalize the frequency of X-Rays based on an individualized assessment of each child’s risk for decay and a clinical exam. In every instance, we’re happy to tell you exactly why we’re recommending an X-Ray and what clinical factors influenced that decision. Additionally, we’ve invested in state-of-the-art digital X-Ray technology to further enhance the diagnostic quality of our images and lessen our environmental impact.
Ionizing radiation, including X-Rays, is a naturally occurring phenomenon which we’re all exposed to on a daily basis. Keep in mind that there are several sources of ionizing radiation already in the environment; for example, naturally occurring radon in the Earth and solar radiation from the sun. To better assess the risk of ionizing radiation, we can compare the radiation dosage from a dental X-Ray to the radiation exposure we encounter through our day-to-day activities.
One scientific unit of measurement of a radiation dose is the micro-Sievert (uSv). In general, the average person in the U.S. receives an effective dose of about 3000 uSv per year from naturally occurring radioactive materials and cosmic radiation. The effective dose varies throughout the country, but is stronger at higher altitude. People living in the plateaus of Colorado or New Mexico receive about 1500 uSv more per year than those living near sea level. In fact, you are exposed to cosmic radiation every time you fly at a rate of 5uSv per hour.
So, for a four bitewing exposure, the estimated effective dose is 5 uSv. Thus, those who have implemented high speed films, or even better, have gone green with digital, have reduced your radiation exposure to an area smaller than the lid of your child’s sippy cup and the equivalent exposure of taking a one hour flight to Disneyland- 5 uSV as published in the 2006 ADA publication Dental X-ray Examinations: Answers to Common Questions.
Did you know that a mammogram exposes you to 700 micro-Sieverts as published in a March 15, 2011 Los Angeles Times Article: ”You’re being exposed to radiation — but it’s the amount that counts”. What about other procedures or activities? See Below:
Comparison of Radiation Effective Dose from Various Dental and Medical Image Procedures to Natural Background Radiation
From The Alliance for Radiation Safety in Pediatric Imaging. ImageGently.org
1 Panoramic X-ray
4 bitewing X-rays
CBCT (both jaws)
Chest X-ray (single view)
Chest X-ray (2 view)
Estimated Effective Dose
up to 10 uSv
up to 100 uSv
up to 2000 uSv
up to 3000 uSv
up to 5000 uS
Equivalent Amount of Background Radiation
up to 3 days
up to 30 days
up to 8 months
up to 12 months
up to 20 months
Based on these measurements, a set of 2 digital bitewing X-Rays (the most common X-Ray we take) is the equivalent of less than one day’s worth of existing background radiation.
The Radiological Society of North America concluded that:
“Properly conducted imaging carries minimal risks and should be performed when clinically indicated. The amount of radiation used in most examinations is very small and the benefits greatly outweigh the risk of harm.”
While we believe the risks of occasional digital X-Rays is negligible, we aim to minimize the exposure as much as possible. We always base the frequency and type of X-Rays on your child’s individual risk. We often say that “We treat each child as if he or she was our own” and children in our families have dental X-Rays taken when prescribed.
The information contained in this publication is provided through Image Gently, the educational and awareness campaign created by the Alliance for Radiation Safety in Pediatric Imaging, formed in July 2007 and with contribution from my colleague- Dr. Gila Dorostkar. It is a coalition of healthcare organizations dedicated to providing safe, high quality pediatric imaging nationwide. The Society for Pediatric Radiology as well as over 33 other societies (including the American Academy of Oral and Maxillofacial Radiology) are members of this coalition representing more than 500,000 health care professionals in radiology, dentistry, pediatrics, medical physics, and radiation safety.
Careless Use X-Rays
Dental X-Rays and Pregnancy
The Society for Pediatric Radiology
“What Parents Should Know about the Safety of Dental Radiology” by the Society of Pediatric Radiology
-Dr Jon and Team HappyHealthyTeeth