This study provides a comprehensive overview of Diagnostic Reference Levels (DRLs) for dental Cone Beam Computed Tomography (CBCT), addressing the current variability and challenges associated with their implementation. Data were collected through a survey conducted among members of the Dental Imaging Special Interest Group of the European Federation of Organizations for Medical Physics, encompassing 33 countries, not limited to Europe. The focus was on official DRL documentation issued by regulatory or authorized bodies and peer-reviewed publications based on data from more than ten CBCT units.

Official DRLs were identified in Finland, Germany, Ireland, Italy, Greece, the United Kingdom, Sweden, Japan, Switzerland, and Estonia. DRLs were analyzed using two primary classification schemes: by field of view (FOV) dimensions and by clinical application or indication. The application of differing methodologies across countries was a key finding. In the clinical application-based group DRLs ranged from 200 mGy·cm² for imaging a single jaw quadrant in Sweden to 1150 mGy·cm² for paranasal sinus imaging in Finland. The United Kingdom was the only country to establish pediatric-specific DRLs. For FOV-based DRLs, values ranged from 500 mGy·cm² for FOVs ≤ 25 cm², in Germany, to 1960 mGy·cm² for a > 100 cm² FOVs, in Japan. The variability in exposure parameters and data reporting practices complicates cross-country comparisons.

To improve radiation safety, the harmonization of DRLs is essential. Increased international collaboration, the standardization of dose metrics, and enhanced training for dental professionals are critical steps toward the implementation of evidence-based DRLs and the optimization of CBCT practices worldwide.