# Evaluation of Operator and Patient Doses after Irradiation with Handheld X-ray Devices
## 2 Methods and Materials
The energy of the dosimeters was discharged by heating them again at 225 \({}^{\circ}\)C for 10 min. The irradiation process of the dosimeters with an X-ray source whose radiation amount is known was repeated to find the element correction coefficients (ECC). The calibration process was completed by reading  
Figure 1: Mannequin with protective equipment. Figure 2: Phantom head and handheld device with TLDs on during exposures. the dosimeters again in the appropriate set-up in the WinREMS software program on the TLD-reader device. After each irradiation, the dosimeters were read in the TLD reader after 12 h. The dosimeters, whose readings were made, were heated at 225 \({}^{\circ}\)C for 10 min and their absorbed energy was discharged. For the next irradiation, the dosimeters were placed on the phantom head and the devices in locked bags. Organs and tissues that were selected for the determination of radiation dose within the scope of this study were:  
On the patient's/phantom's head;  
Thyroid (skin dose (SD));  
Right--left eyes;  
Right--left parotid glands (SD);  
Right--left submandibular glands (SD);  
Sublingual gland (SD). On personnel/mannquin;  
Gonads (SD);  
Thyroid (SD);  
Right--left eyes;  
Right--left hands. TLDs were placed on the phantom head, mannequin, and devices in locked bags for irradiation, three in each area and four on the cone (Figure 2). Unlike the other two devices, since the NOMAD Pro 2 TM device has a protective disc, TLDs were placed in front of and behind the protective disc, and irradiations were made. All irradiations were made by placing the same dosimeters in the same area during the experiments. In the experiments, irradiations were made for the following series of radiographs with each handheld X-ray device:  
- Conventional (Kodak Dental Carestream E-speed, Rochester, NY, USA) intraoral whole-mouth radiograph series (2 right and left bitewing, 7 maxillary periapical radiographs, 7 mandibular periapical radiographs; a total of 16 irradiations);  
- Phosphor plate (GXPS-500 PSP, Hatfield, PA, USA) intraoral whole mouth radiograph series;  
- RVG (CMOS) system (GENDEX GXS-700\({}^{\mathrm{TM}}\), Hatfield, PA, USA) intraoral whole mouth radiograph series. While the irradiations were performed, the NOMAD Pro 2\({}^{\mathrm{TM}}\) device; 60 kVp, 2.5 mA, Rextar X device; 70 kVp, 2 mA, Diox 602 device; and 60 kVp, 2 mA were used within those parameters, and times specified in Table 1 (recommended by the manufacturers). \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Interation Times (s) for Conventional Systems** & & \\ \hline  & **Anterior** & **Posterior** & **Bitewing** \\ \hline NOMAD Pro 2\({}^{\mathrm{TM}}\) & 0.30 & 0.38 & 0.40 \\ Rextar X & 0.30 & 0.38 & 0.40 \\ Diox 602 & 0.30 & 0.38 & 0.40 \\ \hline \multicolumn{4}{c}{**Irradiation Times (s) for Photo Stimulable Phosphor Plate Systems**} \\ \hline  & **Anterior** & **Posterior** & **Bitewing** \\ \hline NOMAD Pro 2\({}^{\mathrm{TM}}\) & 0.16 & 0.19 & 0.20 \\ Rextar X & 0.16 & 0.20 & 0.20 \\ Diox 602 & 0.16 & 0.19 & 0.20 \\ \hline \multicolumn{4}{c}{**Irradiation Times (s) for RVG Systems**} \\ \hline  & **Anterior** & **Posterior** & **Bitewing** \\ \hline NOMAD Pro 2\({}^{\mathrm{TM}}\) & 0.12 & 0.16 & 0.17 \\ Rextar X & 0.12 & 0.16 & 0.18 \\ Diox 602 & 0.12 & 0.16 & 0.17 \\ \hline \end{tabular}
\end{table} 
Table 1: Exposure times recommended by the manufacturers. With each device, images were obtained by irradiating at the recommended times in conventional (C), photo-stimulable phosphor plate (P), and RVG (R) systems. Image quality was not evaluated in our study. It was determined how the image would look when irradiated at the times recommended by the manufacturers (Figure 3). Irradiations were performed on the personnel in the designated areas without protective measures and with protective measures. For TLDs to give more accurate measurements, all irradiations were made three times (16 \(\times\) 3), and the average of the values obtained was taken.