Quality control and diagnostic reference levels in intraoral dental radiographic facilities

OBJECTIVES: A quality control program in intraoral radiographic equipment was conducted aiming to verify compliance with the latest legal requirements and to measure radiation dose in order to contribute to the establishment of appropriate diagnostic reference levels. METHODS: This study was performed in 191 intraoral radiographic facilities in Northern Greece. The quality control program included visual inspection of the unit, registration of its characteristics, measurement and calculation of several radiological parameters, including entrance surface dose, and overall compliance with legislation requirements. RESULTS: Most units (61.8%) were found to perform within their corresponding specifications. Exposure timer accuracy was the parameter that the dental units showed the poorest performance. Inadequate beam filtration was found in almost half of the older 50 kVp units. Entrance surface dose showed significant discrepancies, varying from 0.30 mGy to 16.09 mGy with a third quartile value of 3.37 mGy. CONCLUSIONS: A diagnostic reference level of 3.5 mGy is considered to be a realistic value for all intraoral equipment currently operating in Greece. However, for newly installed units, a value of 2.8 mGy is considered to be more appropriate.