Occupational dose assessment for dental assistants using wall-mounted intraoral X-ray units: A prospective study

Background The increasing use of dental radiography may increase occupational radiation exposure. Although dental radiographs support clinical decision-making, minimizing exposure to patients and staff remains essential for radiation protection and the ALARA principle. Objective This prospective observational study aims to assess dental assistants’ personal dose equivalent, Hp(10), during routine dental radiography, encourage regular monitoring among dental workers, and raise awareness of radiation protection practices. Methods 14 dental assistants involved in radiographic duties were enrolled. Each participant wore a chest-level Optically Stimulated Luminescence (OSL) badge reporting Hp(10), using Aluminum Oxide doped with Carbon (Al2O3:C). Readings were obtained after three-month monitoring period. The measured quarterly values were multiplied by four to estimate annualized doses, assuming the monitoring period represented annual practice. The number of radiographic exposures, repeated images, and exposure parameters were documented. Results The measured three-month Hp(10) values ranged from 0.16 to 0.26 mSv. Annualized Hp(10) estimates ranged from 0.64 to 1.04 mSv/year, with a mean of 0.77 ± 0.12 mSv/year and a median of 0.76 mSv/year. The highest estimate was recorded for an assistant working in an endodontic clinic. Overall, 874 radiographic exposures and 85 repeated images were recorded, giving a repeat proportion of 9.7%. Individual repeat rates ranged from 0% to 31.8%. Because assistants with the highest workloads did not consistently record the highest doses, workload alone did not fully explain the observed variation. Conclusion The measured occupational Hp(10) values among the participating dental assistants were low. All annualized Hp(10) estimates were substantially below the numerical value of the occupational effective-dose limit. Nevertheless, one annualized Hp(10) estimate slightly exceeded 1 mSv/year, supporting risk-based personal monitoring for assistants who regularly perform or assist with dental radiography. Radiation-protection training, avoidance of manually holding image receptors or X-ray equipment during exposure, workload review, and adherence to the ALARA principle should be reinforced.