Answer to Question #8232 Submitted to "Ask the Experts"

Category: Medical and Dental Equipment/Shielding — Equipment

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


I found a dentist covered by my insurance. He has an older Marksman I dental x-ray machine that he said "became digital" and has something placed in the column to reduce x rays. The machine is large, old-fashioned looking, and grey and has a needle knob that he states he can turn down to "even a 5 or 6." He states people come in to check it routinely to check for leaks and "they were glad he went digital" with this machine.

My previous dentist had a new-looking digital x-ray machine that was not as large, although he used the "D" speed film. How much of a range of exposure difference could there be and what other questions should I ask about the new dentist's equipment? He does have a lead apron and collar and does my records in front of me on a liquid crystal display-type screen that includes demonstrations on different procedures which he does in his office. The only old-looking things are the cabinets and this machine.


X-ray equipment is regulated by the state that you are in. Assuming that your dentist has his x-ray equipment registered with the state, he is required to follow state regulations regarding radiation safety of x-ray equipment. This includes equipment function and the operation of that equipment by qualified personnel (i.e., a dentist or a dental hygienist) in a manner to obtain the optimal diagnostic image while keeping radiation dose low. In addition, states inspect x-ray facilities on a regular basis (length of time varies by state) to assure compliance with the regulations. If all of the above is happening, then the age of the equipment should not matter significantly in regard to your safety from excess radiation exposure.

Ken "Duke" Lovins, CHP

Answer posted on 6 April 2009. 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.