I think it is very important for patients to understand the risk vs benefit and indications for dental radiographs or x-rays. Patients often express concern about the amount of radiation exposure that they will receive from a dental radiograph. This is a very valid concern, and with cumulative effects, radiation exposure can be harmful. As humans on earth we are exposed to low levels of radiation from the atmosphere daily. The good news is that radiation exposure associated with dentistry only makes up a minor contribution compared to total exposure from all other sources. Let’s look at the numbers for a better comparison.
Radiation exposure is compared in a common scaled called effective dose that is measured in Microseverts (µSv)
Average daily Atmospheric background radiation (per person in the US)- ~8µSv
4 Bitewing radiographs- ~5µSv
1 Panoramic Radiograph- ~16µSv
2 Hour Commercial Flight (example Dallas to Chicago) ~5µSv
The need for radiographs is crucial in order for the best diagnosis to be made. We are trained to use the principal of ALARA (As Low As Reasonably Achievable) in order to make a diagnosis. There is a balance that must be achieved between limiting radiation exposure and being able to make accurate diagnosis. When completing a visual exam of a patient's mouth, there are generally 2 out of 5 surfaces per tooth or 40% of the tooth that cannot be seen clinically. These are the spaces between teeth, where floss passes, and these are highly susceptible areas for decay. This is the reason that we recommend bitewing radiographs on a regular basis to allow us to monitor these surfaces. Bitewing radiographs also allow us to monitor the bone levels around teeth and ensure that bone loss is not occurring. The panoramic radiograph is generally recommended once every 5 years and this allows us to see your entire jaw, sinuses and all teeth in one image- this is a great tool to monitor for any pathology or irregularities that cannot be seen below the surfaces of the tissue.
In our office, we use only digital radiographs- these allow for the lowest level of radiation exposure to the patient (when compared to conventional film x-rays). With each patient, it is our goal to provide the most accurate diagnosis; which in many cases requires adjunctive tools such as radiographs. Hopefully this entry has given some insight to the importance of dental x-rays and the amount of relative radiation risk that they pose.
For more information visit the American Dental Association Website below: