This is a hot topic! Literally! Some of the most frequent questions I get asked in the office are about radiographs (x-rays). Do my kids really need them? Is it safe? So I thought I’d share some of the basics when it comes to dental radiography and some of my favorite resources.
Why do children and adults require dental x-rays? X-rays help us check for cavities on surfaces we cannot see or feel with dental instruments (between teeth). They
are also vital to check for things such as extra or missing teeth, pathology, and help us monitor a child’s growth and development.
When people are talking about radiation and dosages, they are referring to micro-Sieverts or Sv. Cavity-detecting x-rays that check for decay between teeth are called “bitewings.” On children less than 6 years old, we often only take two bitewing x-rays (one on each side). Once permanent teeth come in, four bitewing x-rays are needed (two on each side). Four bitewing radiographs deliver a total of 5 Sv of radiation.
To put this in perspective, I’ll share a few other interesting facts.
The average person receives a dose of 10 Sv on the average day from background radiation like sunlight.
400 Sv is the yearly dose an average person gets from eating food! Bananas are radioactive at 0.1 Sv.
The EPA put a yearly limit on radiation dosage to members of the public at 1,000 Sv.
The risk of harm is dependent on both the dose and the dose rate, or in other words, the time that the body is exposed to that dose. So a large dosage over a greater period of time is less concerning than that same dosage in a very short period of time. Digital radiography significantly reduces the amount of radiation that patients are exposed to. One of the more sensitive organs to radiation is the thyroid gland. This is why we always use a thyroid shield, and we lower the dosage to a “child-size” exposure time. In this way, I limit X-ray exposure to only that which is needed.
I follow the guidelines from the American Academy of Pediatric Dentistry when prescribing dental radiographs. These guidelines were adopted from the ADA and the FDA. The table in the above link is very useful!
If you want to learn more about x-rays, go to this site by the ADA.
And of course, feel free to ask me any questions! We hope your new year is off to a great start!