Dental X-Rays

“We live in a radioactive world – humans always have. Radiation is part of our natural environment. We are exposed to radiation from materials in the earth itself, from naturally occurring radon in the air, from outer space, and from inside our own bodies (as a result of the food and water we consume). This radiation is measured in units called millirems (mrems).

The average dose per person from all sources is about 620 mrems per year. It is not, however, uncommon for any of us to receive less or more than that in a given year (largely due to medical procedures we may undergo). International Standards allow exposure to as much as 5,000 mrems a year for those who work with and around radioactive material.”

American Nuclear Society (estimate your annual radiation exposure here)

Common x-rays that are taken in a dental office include: Bitewings, Periapicals and a Panoramic

BITEWING (BWx)

Detects decay, periodontal disease, dental relationships
4 BWx = 0.5 mrem

PANORAMIC (PANO)

Evaluates growth and development, pathology, TMJ, and may detect decay and periodontal disease.
1 PANO = 0.7 mrem

PERIAPICAL (PA)

Detects decay, periodontal disease, and development.
1 PA = 0.125 mrem

According to the CDC website

We inhale 228 mrem of radiation a year (mostly as radon gas)
Flying round trip from the US East coast to West coast is 7 mrem
Annual radiation we ingest from our food and water is 30 mrem
A Mammogram is around 72 mrem
4 BWx Dental x-rays are about 0.5 mrem

Most of us do not have a context for these measurements. So lets provide some context. Let’s multiply our average annual mrem  dose by three to give us 1860, and instead of mrem, lets call them calories. “1860 calories”, we know what that means. It is near our daily consumption of calories. Now, lets multiply the above examples to continue this comparison.

We inhale “684 calories” of radiation per year
Flying round trip from the US East coast to West coast is “21 calories”
Annual radiation we ingest from our food and water is “90 calories”
A Mammogram is around “216 calories”
BWx Dental x-rays are about “1.5 calories”

Refusing dental x-rays to avoid radiation, is similar to refusing gum to avoid calories.

How often should Dental x-rays be taken?

 Dental x-rays are taken to diagnose decay (cavities), periodontal disease, or to monitor developmental growth and dental/skeletal relationships. Almost every human will experience decay or periodontal disease at some point. We can wait for pain to alert you to a problem (this might mean you need a root canal!), we can wait for your tooth to fall out to diagnose gum disease, or, we can look for early signs of cavities and gum disease, with x-rays.  The American Dental Association and the FDA collaborated to provide recommendations for each age group (based on tooth  development), and ones risk for periodontal disease/cavities. (To find out if you are at an increased risk of decay, click here).

2015 ADA/FDA recommendations for Dental radiographs (Based on development and risk)

 Child with Primary Dentition (“Only baby teeth present”)

  • New Patient Visit: Selected PA’s/occlusal/BWx radiographs
  • Recall, increased risk of decay: BWx every 6-12 months, if surfaces between teeth are not visible
  • Recall, not at increased risk of decay: BWx every 12-24 months, if surfaces between teeth are not visible
  • Recall, with history of periodontal disease: Clinical judgement needed, BWx/PA’s (frequency not specified)
  • New and Recall, for monitoring developmental growth and dental/skeletal relationships: Clinical judgement needed (frequency not specified)

 Child with Transitional Dentition (“At least one permanent tooth”)

  • New Patient Visit: Selected PA’s/occlusal/BWx radiographs
  • Recall, increased risk of decay: BWx every 6-12 months, if surfaces between teeth are not visible
  • Recall, not at increased risk of decay: BWx every 12-24 months, if surfaces between teeth are not visible
  • Recall, with history of periodontal disease: Clinical judgement needed, BWx/PA’s (frequency not specified)
  • New and Recall, for monitoring developmental growth and dental/skeletal relationships: Clinical judgement needed (frequency not specified)

 Adolescent with Permanent Dentition (“Adult teeth, but no wisdom teeth yet”)

  • New Patient Visit: BWx and PA’s, or BWx and Pano
  • Recall, increased risk of decay: BWx every 6-12 months, if surfaces between teeth are not visible
  • Recall, not at increased risk of decay: BWx every 12-24 months, if surfaces between teeth are not visible
  • Recall, with history of periodontal disease: Clinical judgement needed, BWx/PA’s (frequency not specified)
  • New and Recall, for monitoring developmental growth and dental/skeletal relationships: Clinical judgement needed (frequency not specified)

 Adult, Dentate or Partially Edentulous (All or some permanent teeth)

  • New Patient Visit: BWx and PA’s, or BWx and Pano
  • Recall, increased risk of decay: BWx every 6-18 months
  • Recall, not at increased risk of decay: BWxevery 24-36 months
  • Recall, with history of periodontal disease: Clinical judgement needed, BWx/PA’s(frequency not specified)
  • New and Recall, for monitoring developmental growth and dental/skeletal relationships: Clinical judgement needed (frequency not specified)

Radiation During Pregnancy?

The American College of Obstetricians and Gynecologists support the use of x-rays during pregnancy. The risk of complications from oral infection outweigh the risk of radiation exposure. Click here to read their article from October 2017.

Here is the ADA’s statement from their website:

“Concern exists for the safety of dental X-rays in pregnant patients and operators.  The ADA recommends the use of aprons and thyroid shields for pregnant patients, and dosimeters and work practice controls for pregnant operators.2  Studies of pregnant patients receiving dental care have affirmed the safety of dental treatment.11, 12 The American College of Obstetricians and Gynecologists Committee on Health Care for Underserved Women reaffirmed its committee opinion in 2015: “Patients often need reassurance that prevention, diagnosis, and treatment of oral conditions, including dental X-rays (with shielding of the abdomen and thyroid) … [is] safe during pregnancy.13″

 

Don’t know if you are at an increased risk for decay? Your Dental Hygienist can help you complete a risk assessment.