title: Diagnostic reference levels in intraoral dental radiography in Korea.
abstract: OBJECTIVE
  The objectives of this study were to survey the radiographic exposure parameters, to measure the patient doses for intraoral dental radiography nationwide, and thus to establish the diagnostic reference levels (DRLs) in intraoral dental X-ray examination in Korea.
  
  
  METHODS
  One hundred two intraoral dental radiographic machines from all regions of South Korea were selected for this study. Radiographic exposure parameters, size of hospital, type of image receptor system, installation duration of machine, and type of dental X-ray machine were documented. Patient entrance doses (PED) and dose-area products (DAP) were measured three times at the end of the exit cone of the X-ray unit with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for adult mandibular molar intraoral dental radiography, and corrections were made for room temperature and pressure. Measured PED and DAP were averaged and compared according to the size of hospital, type of image receptor system, installation duration, and type of dental X-ray machine.
  
  
  RESULTS
  The mean exposure parameters were 62.6 kVp, 7.9 mA, and 0.5 second for adult mandibular molar intraoral dental radiography. The mean patient dose was 2.11 mGy (PED) and 59.4 mGycm(2) (DAP) and the third quartile one 3.07 mGy (PED) and 87.4 mGycm(2) (DAP). Doses at university dental hospitals were lower than those at dental clinics (p<0.05). Doses of digital radiography (DR) type were lower than those of film-based type (p<0.05).
  
  
  CONCLUSIONS
  We recommend 3.1 mGy (PED), 87.4 mGycm(2) (DAP) as the DRLs in adult mandibular molar intraoral dental radiography in Korea.
authors.affiliation: Department of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan, Korea.
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Won-Jeong
authors.initials: WJ
authors.lastname: Han
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Choi
authors.forename: Yun-Hoa
authors.initials: YH
authors.lastname: Jung
authors.forename: Suk-Ja
authors.initials: SJ
authors.lastname: Yoon
authors.forename: Jae-Seo
authors.initials: JS
authors.lastname: Lee
keywords: Radiation Dosage; Radiation Protection; Radiography, Dental