# Comparison of the Operator and Surrounding Dose When Using Portable Intraoral X-ray Devices
###### Abstract  
This study aimed to investigate the scattered radiation dose using three portable dental radiographic units: iRay D3, EZRay Air, and Epix. The absorbed dose was measured at 0.5 and 1 m distances, every 15\({}^{\circ}\) in the horizontal plane, using an ionization chamber. The maximum number of radiographs per day using the portable units was calculated considering a dose limit of 50 mSv/year and 20 mSv/year. The doses were higher in the Epix unit compared to the other two devices. Anterior exposure was generally higher than the sides or posterior exposure. With a dose limit of 50 mSv/year, considering a distance of 0.5 m between the operator and the X-ray unit, a maximum of 961, 565, and 38 radiographs are permitted daily using iRay D3, EZRay Air, and Epix, respectively. Considering a dose limit of 20 mSv/year, with a distance of 0.5 m between the operator and the radiographic device, a maximum of 384, 226, and 15 radiographs are permitted daily using iRay D3, EZRay Air, and Epix portable units, respectively. It is highly unlikely that an operator would reach occupational dose limits when using iRay D3 and EZRay Air. The Epix radiographic device allows for fewer daily radiographs and should be avoided for daily use. radiation; radiation protection; radiation dosage; dental radiography +
Footnote †: journal: Medical  
from the body parallel to the floor. Nevertheless, concerns exist regarding the operator's dose during exposure with handheld dental X-ray devices [8]. In addition, these portable radiographic units can also be equipped with a remote exposure button, allowing the operator to place the portable device on a stationary tripod and stand farther away from the X-ray source. However, the principal difference between portable and conventional wall-mounted units is the fact that the operator often touches the X-ray generator during the action of taking radiographs [9]. Several studies have evaluated radiation safety and dosage of portable X-ray devices [7; 10]. [PERSON] et al. conducted a study to measure the radiation dose received by operators using the Nomad portable device and reported that the whole-body annual dose amounted to 0.047 mSv, which corresponds to only 0.09% of the annual dose limit of 50 mSv [11]. In another investigation, [PERSON] et al. utilized the Rextar X handheld dental radiography unit. They reported absorbed doses resulting from a single adult maxillary molar radiography: 0.69 \(\upmu\)Gy at the left hand, 0.78 \(\upmu\)Gy at the right hand, and 0.47 \(\upmu\)Gy at the operator's eyes [12]. Additionally, [PERSON] et al. studied operator doses while using a portable radiographic device in various positions. Notably, the received dose was higher when the operator's arm was bent [8]. Lastly, [PERSON] et al. employed a Geiger Muller counter and found that the radiation dose near the Port-XII portable device remained below the annual dose limit [13]. However, there are some concerns regarding various aspects of radiation safety, especially in newly developed radiographic units. Several organizations in different parts of the world have set public and occupational dose limits per annum. The International Commission on Radiation Protection (ICRP) has suggested an annual occupational dose limit of 20 mSv (averaged over 5 consecutive years). In the United States, however, the National Council on Radiation Protection and Measurements (NCRP) enforces an annual dose limit of 50 mSv for radiology personnel, a limit higher than ICRP recommendations [13; 14]. These occupational dose limits are established to ensure that operators do not encounter any deterministic effects, while also minimizing the risk of stochastic effects. Therefore, the exposure specifications claimed by manufacturers of different radiographic devices must be tested in experimental settings to ensure their safety. This study aimed to measure the absorbed radiation dose using three different portable dental radiographic units.