# Comparison of the Operator and Surrounding Dose When Using Portable Intraoral X-ray Devices
## 4 Discussion
However, in scenarios involving the imaging of mass disasters which may entail multiple radiographic exposures by a single operator, both radiation protection and a controlled area become crucial safety considerations. Additionally, it is worth mentioning that patients often require several radiographs, and the number of permitted daily radiographs must not be mistaken for the number of patients. Therefore, the Epix portable dental radiographic system is not suitable for obtaining radiographs on a daily basis, particularly with shorter distances between the operator and the portable dental radiographic unit. Portable dental radiographic units are an indispensable tool in dentistry and forensics, allowing for access to radiographic evaluation of the dentition and surrounding structures in underprivileged zones, nursing homes, hospitals, and disaster scenes. Studies have shown that radiographic images obtained by these units have comparable quality with that of wall-mounted ones. [PERSON] et al. have shown that the percentage average error value of the tube voltage is lower than the standard. Therefore, they concluded that images of appropriate quality can be taken with a portable unit, offering acceptable diagnostic value [18]. In another study, [PERSON] et al. examined the subjective quality of bitewing radiographs obtained by handheld and stationary dental radiographic units. They reported that subjectively assessed diagnostic image quality in bitewing radiographs acquired by handheld and stationary X-ray devices did not differ significantly [19]. Another study by [PERSON] et al. revealed that while no significant difference existed between the wall-mounted and portable dental radiographic devices in sharpness, contrast, and error in vertical regulation, there is a significant difference between the two groups in cone-cutting and error in horizontal angulation of intraoral radiographs. The images taken with portable devices showed better image quality, as judged by five observers, compared to the stationary device [20]. Concerns over the safety of portable dental radiographic units, as well as the difficulty to ensure the correct geometry of the source, intraoral detector, and patient can be considered as the main pitfalls of these handheld dental X-ray units. Therefore, a general suggestion is that handheld intraoral dental radiographic units should supplement but not replace conventional radiographic equipment for daily practice [9]. As mentioned, there are currently two sets of occupational dose limits. The NCRP enforces a dose limit of 50 mSv per year, while the ICRP recommends a more conservative annual dose limit of 20 mSv averaged over 5 consecutive years. The ICRP was established in 1928 following the initiative of the first International Congress of Radiology held in 1925. This organization has made general recommendations on limits of exposure for radiation workers and public. The NCRP was established in the United States in 1929 as the national counterpart to the ICRP. Initially conceived as an advisory committee for the United States members of these international bodies, the NCRP quickly gained independence and began making recommendations for use within the United States, starting in 1931. Over time, it evolved into a formal Council with a charter from the United States Congress in 1964 [21]. The NCRP also offers dose limit recommendations which closely resemble those set by the ICRP. However, there are occasional variations. The key differences between recent limits lie in the greater flexibility that the NCRP allows when formulating recommendations. The dose limits recommended by both organizations have generally decreased in each recommendation, since their establishment [21; 22]. The shift in radiation protection guidelines has been driven by the recognition that deterministic effects--those directly causing tissue damage and cell death--are not the primary limiting factor.