Answer to Question #9954 Submitted to "Ask the Experts"

Category: Medical and Dental Equipment/Shielding — Shielding

The following question was answered by an expert in the appropriate field:

I'm a dental assistant and I recently got hired at a new practice. I'm loving it there, however there are a few things that are concerning me.
  1. The wall that I go behind to take the x ray does not have lead barrier. It is a glass wall.
  2. The cabinets that separate the operatory also do not have lead.
  3. We take panoral x rays in another room and I go behind a wall to push the button. I don't think that machine is six feet apart from the button.
Am I safe? Am I being exposed to radiation?
In a summary answer to all of your questions, it is very common for dental installations (intraoral and panoral units) to utilize only common construction materials for shielding. This means that many dental facilities of this type are adequately shielding with standard drywall or similar materials.

Intraoral units usually have the x-ray exposure switch outside the room on a wall, with the standard construction wall (drywall) between the operator and the x-ray unit and patient. In your case, you have indicated a glass wall. It is likely that a glass wall has been determined sufficient or it could be made of lead-impregnated glass offering additional shielding protection.

Some facilities install cabinets or other types of ‘walls’ between operatory areas. If planned appropriately, this can be acceptable as well and is very common. Sometimes these cabinets may even have an intraoral x-ray unit inside that can be used for two adjacent operatories.

Typical panoral installations have a control switch mounted on a wall next to or near the x-ray unit. It is not uncommon for that switch to be within a few feet of the unit and separated from that unit with standard drywall construction.

X-ray use is regulated by the state that your facility is located in. They have a process for registration of facilities and the x-ray units they use. There are also requirements regarding shielding for various types of x-ray installations and “what is acceptable” can vary greatly depending on many factors such as type of x-ray unit, distance from the unit, number of x rays taken, what occupies an adjacent area, etc. If your facility is properly registered and in compliance with state regulations (as determined by routine state inspections), then the scenarios you describe are acceptable for that particular situation and you should be adequately protected from radiation dose within state dose limit requirements.

Kennith “Duke” Lovins, CHP
Health Physicist
Answer posted on 9 November 2011. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.