title: Comparison of radiation levels from computed tomography and conventional dental radiographs.
abstract: BACKGROUND
  With the increasing use of computed tomography (CT) in oral diagnosis and treatment planning, concern has been expressed about the high levels of radiation used, and the associated risks.
  
  
  OBJECTIVE
  The purpose of this study was to compare the radiation doses of facial CT scans with the radiation doses taking a lateral cephalometric radiograph, a panoramic radiograph (OPG), an occlusal film, and an intra-oral periapical radiograph.
  
  
  METHODS
  An Alderson-Rando anthropomorphic phantom head was used for the analysis. Thirty-six lithium fluoride thermoluminescent dosimeters were placed in the phantom head in locations representing radiosensitive sites. Standard facial CT scans and conventional radiographs (lateral cephalometric, OPG, maxillary occlusal, intra-oral periapical) were then taken of the phantom head.
  
  
  RESULTS
  The following radiation doses were measured: maxillo-mandibular CT scan, 2.1 mSv; maxillary CT scan, 1.40 mSv; mandibular CT scan, 1.32 mSv; lateral cephalometric radiograph, 0.005 mSv; OPG, 0.010 mSv; maxillary occlusal, 0.007 mSv; intra-oral periapical radiograph, 0.005 mSv.
  
  
  CONCLUSIONS
  CT scans produce significantly more ionising radiation than conventional radiographs. This factor should be taken into account when considering a CT scan as an alternative to a survey with conventional radiographs. While CT scans offer many advantages over conventional radiography the high radiation dose to patients, and the cost of this procedure should be considered.
authors.affiliation: Discipline of Orthodontics, The University of Sydney, Surry Hills, NSW, Australia.
authors.forename: Daniel C S
authors.initials: DC
authors.lastname: Ngan
authors.forename: Om P
authors.initials: OP
authors.lastname: Kharbanda
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Geenty
authors.forename: M Ali
authors.initials: MA
authors.lastname: Darendeliler
mesh_terms: D001921:Brain / Q000528:radiation effects; D002508:Cephalometry; D005459:Fluorides; D006801:Humans; D007908:Lens, Crystalline / Q000528:radiation effects; D018020:Lithium Compounds; D008334:Mandible / Q000528:radiation effects; D008437:Maxilla / Q000528:radiation effects; D010306:Parotid Gland / Q000528:radiation effects; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011861:Radiography, Dental / Q000145:classification; D011862:Radiography, Panoramic; D012867:Skin / Q000528:radiation effects; D013819:Thermoluminescent Dosimetry; D013961:Thyroid Gland / Q000528:radiation effects; D014057:Tomography, X-Ray Computed
chemical_list: D018020:Lithium Compounds; C027651:lithium fluoride; D005459:Fluorides