National dose survey and discussion on establishing diagnostic reference levels for dental imaging in Korea

This study aimed to establish updated diagnostic reference levels (DRLs) for dental imaging modalities in South Korea.

In cooperation with the Korea Disease Control and Prevention Agency, various types of institutions (dental clinics, dental hospitals, and dental university hospitals) were selected to investigate the status of diagnostic radiation equipment use. Subsequently, over 300 units were randomly selected for each imaging device type (intraoral, panoramic, and cone-beam CT [CBCT]) as measurement samples. DRLs were defined as the 75th percentile of the dose area product distribution. The differences in dose were analysed based on the type of institution, age of use, country of manufacture, and presence of a multifunction device.

The national DRLs for dental imaging established in this survey were as follows: intraoral imaging at 48 mGy·cm2 for adults and 31 mGy·cm2 for children; panoramic imaging at 354 mGy·cm2 for adults and 224 mGy·cm2 for children; and CBCT at 1856 mGy·cm2 for adults and 1350 mGy·cm2 for children. Private dental clinics and hospitals recorded approximately twice the dose levels of university dental hospitals. CBCT devices in dental hospitals and those that have been in used for 5-10 years showed significantly high radiation doses.

The DRLs established through this study were found to be significantly increased, especially in adult and paediatric panoramic radiographs and paediatric CBCT images, compared with those in previous surveys; moreover, they were higher than those in other countries. The findings of this study can serve as a basis for national dose reduction efforts.