Answer to Question #10721 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
My son was in the dentist's office having his six-month checkup. The x-ray machine was right outside the room where he was having his checkup and the girl was pressing the button a few times even though no one was standing in front of the machine receiving an x ray. Do you know why she would press the button on the x-ray machine when no one was having an x ray?
The most probable answer is that the office was evaluating the technical settings for a direct digital sensor. Today's sensors are extremely sensitive to radiation and are measured not in tenths of seconds of radiation exposure, but in hundredths of seconds; for example, in my dental school clinic, our "standard" setting is 0.08 seconds, that is, eight hundredths of a second. And, of course, we change this for smaller patients and larger patients accordingly as needed. As a result, it does not take very much for the settings for these machines to get out of adjustment. So the technical settings for the machine could have been changed somehow and the staff member was readjusting the machine while imaging a small radiopaque object to make sure the settings were properly adjusted. Another consideration is that the office may have recently purchased a new digital sensor and was in the process of adjusting settings to determine the optimal technical settings for the machine so that the best exposures could be obtained clinically.
I hope this answer is helpful with your question!!
Jeffery B. Price, DDS, MS