Dose Assessment in Eye Lens and Larynx for Periapical and Opg Imaging Using a Bismuth Based Thyroid Collar and Rando Phantom Publisher



Malekie S ; Shahbazi L ; Kashian S ; Sardari D ; Saadi M K ; Rezaeian P ; Moslehi A ; Hajiloo N ; Adeli R ; Aghdam S R H ; Akbari M ; Ziaie F
Source: Journal of Radioanalytical and Nuclear Chemistry Published:2026

Abstract

This study evaluates the efficacy of a bismuth oxide/silicone rubber (Bi2O3/SR) composite thyroid collar in reducing radiation doses to the eye lens and larynx during periapical (PA) and orthopantomogram (OPG) dental imaging. Using a head-neck section of an adult male Rando phantom equipped with GR-200 thermoluminescent dosimeters (TLDs), measurements were conducted at standard exposure settings (PA: 60 kV/7 mA/0.32 s; OPG: 75 kV/13 mA/14.1 s). Results demonstrated that the composite shield significantly reduced larynx doses by 23.5% (PA) and 97% (OPG) compared to unshielded conditions, outperforming a commercial lead shield (0.5 mm Pb equivalent) in OPG procedures. For the eye lens, the composite shield achieved a 57.6% dose reduction in OPG imaging, though it showed no significant protection in PA radiography, possibly due to scattering effects. The findings highlight the superior shielding performance of Bi2O3/SR composite thyroid collar in OPG, offering a promising lead-free alternative for minimizing radiation exposure to sensitive tissues in dental radiology. © Akademiai Kiado Zrt 2026.