Creation of a dental X-ray unit with a contactless exposure control switch.

OBJECTIVE: A new dental radiographic unit (DXRU) with a contactless switch for adjusting exposure conditions and a foot-pedal exposure switch was developed to prevent bacterial or viral contamination from patients and was compared with a conventional DXRU with a panel push-button switch with respect to user friendliness. METHODS: 45 fourth-year dental school students carried out intraoral radiography using both types of DXRU. Errors regarding dose shortages of X-rays were compared and a questionnaire completed. RESULTS: 22 (49%) of the 45 students failed to provide the correct radiographic exposure and the number of errors was 32 for the conventional DXRU, and 4 (9%) students failed to provide the correct radiographic exposure and the number of errors was 4 for our new DXRU, at the first stage (p < 0.001). At the second stage, the number of students who failed to provide the correct radiographic exposure and the number of errors decreased to 12 and 16, respectively, for the conventional DXRU (p < 0.05). 37 (82%) of the 45 students preferred our DXRU because of its contactless switch and the push-pedal exposure switch. CONCLUSIONS: These data suggested that our new contactless mechanism should be used for other DXRUs for contamination control.