Investigation of the effect of thyroid collar, radiation safety glasses and lead apron on radiation dose in cone beam computed tomography.

Objectives: Due to the increasing use of cone-beam computed tomography (CBCT) in dentistry and considering the effects of radiation on radiosensitive organs, the aim of this study was to investigate the effect of shielding on absorbed dose of eyes, thyroid and breasts in scans conducted with different parameters using two different fields of view (FOV).

Methods: Dose measurements were calculated on a tissue-equivalent female phantom by repeating each scanning parameter three times and placing at least two thermoluminescent dosimeters (TLD) on each organ, with the averages then taken. The same CBCT scans were performed in two different FOV with shielding including thyroid collar, radiation safety glasses and lead apron and without shielding. The differences between them were analyzed statistically. Descriptive statistics and the Wilcoxon test were used for data analysis.

Results: The difference between measurements with and without shielding was statistically significant for all scans (p < 0.001). The dose reduction associated with the use of shielding ranged from 26.81% to 52.95%. The dose related to the FOV has shown a significant increase, ranging from 8.30% to 623.54%, due to both the variation in the area affected by the primary beam on the organs and changes in the amount of radiation.

Conclusion: There are significant differences in the absorbed dose depending on shielding and FOV usage. Therefore, the CBCT imaging protocol should be optimized by the operator, and special attention should be paid to the use of thyroid collars and radiation safety glasses, considering their effects on image quality.