Background: Although radiographs are an indispensable diagnostic tool, the increased
effective doses of dental imaging are high enough to warrant reconsideration of means to
reduce patients' exposure.1 Fluoroscopy uses low mA settings as well as image intensification for dose reduction and dynamic imaging acquisition.2
Objective: This investigation proposed to prove the concept of radiation exposure reduction
and dental fluoroscopy feasibility without compromising image quality by testing a low-dose x-ray imaging (LDXI) prototype comprising a 0.2 mA x-ray source and a high quantum efficiency (HQE) intraoral/extraoral sensor and comparing it to standard of care.
Materials & Methods: The Environmental Health and Radiation Safety Institutional Department approved this study. Groups 1 and 2 were exposed to the LDXI static and dynamic modes, respectively. Group 3 was exposed to medical fluoroscopy (MF), group 4 to digital/film-based intraoral radiography (DFIR) and group 5 to CBCT scan. Image resolution was measured (lp/mm).
Preliminary Results: LDXI at 0.2 seconds would reduce 93.45% dosage as compared to DFIR at 0.2 seconds and allowed 15 seconds dynamic imaging for a conventional root canal. The Mann-Whitney test showed no statistical significance (α =0.01) in radiation exposure (mR) between groups 1 and 3 & 1 and 4 and timing exposure (seconds) between groups 1 and 5 & 2 and 3. Dosimeters for the LDXI operator simulated distance and controls did not register significant dose equivalent (mrem). Resolution test showed LDXI1 > DFIR > LDXI2 > MF > CBCT scan.
Future Directions: Lower mA at the x-ray source and HQE image intensification at the sensor level permitted reducing radiation dosage considerably for digital radiography while allowing dynamic fluoroscopy. These principles could be applied to all dental imaging modalities in the near future.
Conflict of interest/acknowledgements: Dr. Yang Consultant and Dr. Uzbelger equity interest in Real Time Imaging Technologies, LLC.
1 Ludlow JB, Davies-Ludlow LE, White SC. Patient risk related to common dental radiographic
examinations: the impact of 2007 International Commission on Radiological Protection
recommendations regarding dose calculation. J Am Dent Assoc. 2008 Sep;139(9):1237-43.
2 Uzbelger Feldman D, Yang J, Susin C. A Systematic Review for the Uses of Fluoroscopy in Dentistry. Chin J Dent Res. 2010 Jun;13(1):23-29.