# Comparison of the Operator and Surrounding Dose When Using Portable Intraoral X-ray Devices
## 4 Discussion  
Based on the findings of this study, the doses were generally higher in the Epix portable dental radiographic unit compared to the other two dental radiographic devices. In all of the portable radiographic units, anterior exposure was higher than side or posterior exposure. Considering a distance of 0.5 m between the operator and the X-ray unit, a maximum of 961, 565, and 38 radiographs per day are permitted using iRay D3, EZRay Air, and Epix portable dental devices, respectively, to reach the NCRP dose limit of 50 mSv. To reach the dose limit of 20 mSv set by ICRP, with a distance of 0.5 m between the operator and the radiographic device, a maximum of 384, 226, and 15 radiographs per day are permitted using iRay D3, EZRay Air, and Epix portable units, respectively. It must be pointed out that due to the settings and specifications of the three portable dental radiographic units, the EZRay Air radiographic device was operated at 2.5 mA, while the iRay D3 and EZRay Air radiographic devices used 2 mA tube currents. [PERSON] et al. measured the dose received by the operator while using a Nomad portable device. According to their findings, whole-body annual dose was 0.047 mSv, 0.09% of the annual dose limit of 50 mSv [11]. In another study, [PERSON] et al. used the Revatz X camera style handheld dental radiography unit. They reported that absorbed doses from a single adult maxillary molar radiography were 0.69, 0.78, and 0.47 uGy at the left hand, right hand, and eyes of the operator, respectively [12]. [PERSON] et al. reported their findings on operator dose while using portable radiographic devices in three different positions. The received dose of the operator's thyroid, eyes, and feet were higher in the bent arm position [8]. In another study, [PERSON] et al. used a Geiger Muller counter and stated that the radiation dose in proximity to the Port-XII portable radiographic device was less than the annual dose limit [13]. In a study conducted by [PERSON] et al., it was observed that when acquiring more than 100 images per day using portable X-ray units, the use of 0.25 mm lead protective clothing or screens was necessary to avoid reaching the 20 mSv dose limit set by ICRP. These protective measures have been reported to reduce scattered rays from 60 kV X-rays by 99% [16]. In another study, [PERSON] et al. compared radiation doses of Nomad Pro 2, Revatz X, and Diox 602 handheld dental radiographic units using calibrated thermoluminescent dosimeters. Their results showed that, for most organs, the Nomad dental X-ray unit led to higher equivalent doses, while for the right hand and left hand, the Revatz X and Diox portable radiographic units had the highest equivalent dose, respectively. Peak measurements without protection were as follows: gonad, 24.4 uGy; thyroid, 30.5 uGy; right eye, 31.9 uGy; left eye, 27.9 uGy; right hand, 111.6 uGy; left hand, 71.7 uGy [17]. While \begin{table}
\begin{tabular}{c c c} \hline \hline
**Radiographic Unit** & **0.5 m** & **1 m** \\ \hline iRay D3 & 961 & - \\ EZRay Air & 565 & 801 \\ Epix & 38 & 190 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Maximum number of radiographs per day using portable dental radiographic devices considering the National Council on Radiation Protection and Measurements (NCRP) dose limits (50 mSv). \begin{table}
\begin{tabular}{c c c} \hline \hline
**Radiographic Unit** & **0.5 m** & **1 m** \\ \hline iRay D3 & 384 & - \\ EZRay Air & 226 & 320 \\ Epix & 15 & 76 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Maximum number of radiographs per day using portable dental radiographic devices considering the International Commission on Radiation Protection (ICRP) dose limits (20 mSv). setting up a controlled area is not imperative for imaging a small number of subjects during visiting care, protective actions--such as wearing appropriate clothing and maintaining a 2 m distance--can mitigate the risk of exposure exceeding the dose limit.