Background and Objective: Given the widespread use of periapical radiography in dentistry, the level of eye exposure to this type of radiography is considerable. However, studies in this area are scarce. Therefore, this study aimed to compare the absorbed dose to the eye lens between the bisecting angle and parallel techniques for maxillary teeth.
Methods: In this cross-sectional study, 16 periapical (PA) radiographs were taken using the parallel technique (PA-Tech) and 16 using the bisecting angle technique (BI-Tech) from the right and left regions of the central and lateral incisors, canine, premolar, and molar teeth (four regions) of the maxilla. Thermoluminescent dosimeters (TLDs) were placed at the lens position of two dental radiographic phantoms. The TLDs were then read and the results were compared.
Findings: The mean absorbed dose to the eye lens on the exposed (dosimetry) side was higher in the parallel technique (0.560±0.324 mGy) than in the bisecting angle technique (0.434±0.386 mGy). Additionally, the mean absorbed dose to the eye lens on the non-exposed side was higher in the parallel technique (0.038±0.022 mGy) than in the bisecting angle technique (0.031±0.011 mGy). No statistically significant difference was observed between the parallel and bisecting angle techniques on either the exposed or non-exposed side. Comparison of the absorbed dose to the eye lens between the exposed and non-exposed sides for both techniques showed that the absorbed dose on the exposed side was significantly higher than on the non-exposed side (p<0.001).
Conclusion: The results of the study suggest that the bisecting angle technique should be used for radiographic imaging of the central incisor and canine regions in order to reduce the radiation dose received by the patient's eyes.