Evaluation of stray radiation to the operator for five hand-held dental X-ray devices.
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ABSTRACT: OBJECTIVES:Evaluate stray radiation to the operator, as represented by a plane within the significant zone of occupancy (SZO), produced by five models of hand-held intraoral dental X-ray devices (HIDXDs). METHODS:The stray radiation for five models of HIDXDs was measured, using an anthropomorphic tissue-equivalent head phantom as a scattering object. An ionization chamber was used to measure the air kerma (?Gy) at 63 positions in a 160 cm high by 60 cm wide plane that was 10 cm behind the X-ray device, identified as being within the SZO. RESULTS:Based on the measured air kerma from stray radiation of five different HIDXDs, the estimated annual air kerma at all measured spatial positions was calculated. When calculated using a median air kerma of 0.8 mGy at the distal end of the cone, as typically required for digital image receptors, 1 the ranges for estimated annual air kerma in the SZO across the devices were 0.14-0.77 mGy for the median, 0.41-1.01 mGy for the mean, and 1.32-2.55 mGy for the maximum. Similarly, when calculated using a median air kerma of 1.6 mGy as typically required for D-speed film, 2 the ranges for estimated annual air kerma across the devices were 0.28-1.54 mGy for the median, 0.83-2.03 mGy for the mean, and 2.64-5.10 mGy for the maximum. CONCLUSIONS:From measured air kerma values of stray radiation in the SZO, estimated annual exposures to the operator for HIDXDs are expected to be greater than from conventional wall-mounted or portable devices activated from a protected area (at a distance or behind shielding). HIDXDs should therefore only be used when patient accessibility makes their use necessary and the use of a portable device on a stand or a wall-mounted device is not reasonably feasible. This approach would keep occupational radiation exposures of dental workers as low as reasonably achievable.
SUBMITTER: Smith R
PROVIDER: S-EPMC6747421 | biostudies-literature | 2019 Jul
REPOSITORIES: biostudies-literature
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