Portable vs. Fixed X-Ray Devices: An Analytical Cross-Sectional Study on the Dentist’s Thyroid Gland Radiation Exposure

Introduction: Occupational exposure from preapical X‑rays may elevate thyroid radiation dose in dentists. This study compared thyroid gland exposure resulting from portable vs. fixed intra‑oral X‑ray devices. Methods: A cross‑sectional field study measured thyroid dose by thermoluminescent dosimeters placed on the anterior neck (thyroid level) using portable and fixed oral X‑ray units during routine preapical imaging. Results: We found a statistically significant difference regarding mean thyroid dose (mGy) between the fixed devices group (n=30, mean = 0.00219 ± 3.84e − 4) and portable devices group ( n  = 30, mean = 0.00536 ± 9.58e − 4) ( P < 0.001). Linear regression model (overall model test: P < 0.001) showed the device type and radiographic technique were significant predictors for thyroid dose ( P < 0.05), while collimation technique and usage of thyroid collar were not significant predictors ( P > 0.05). Conclusions: Portable units pose a higher thyroid exposure risk to dentists.