Applications of xeroradiography in dentistry-a review

Xeroradiography is the technique in which electrostatically charged plates sensitive to X-rays are used in diagnostic radiology in place of conventional film. There has however been anxiety that radiation dosage for xeroradiography may be at unacceptably high levels. James et al., however, in 1973 showed that by increasing the kilovoltage to at least 120 the exposure could be reduced by 60 per cent. Using higher kV lateral oblique jaw and lateral and anteroposterior skull xeroradiographs have been produced with lower radiation exposure than conventional film. Bony detail is much more sharply delineated on xeroradiographs and soft tissues are visible on the same picture without use of a grid or wedge filter. These features are of obvious advantage in cephalometrics and orthognathic surgery. Panoramic techniques are potentially the most useful way of applying xeroradiography. The combination of full jaw coverage with the sharp definition only possible at present with intra-oral radiographs would provide more information for the dentist, save time for the radiographer and reduce the dose to the patient. Excellent results have been obtained with autopsy specimens on machines which develop 90kVp, but optimal exposure for a normal adult requires a panoramic X-ray machine development 120 kVp. Xeroradiography has the advantage, therefore, of providing more detail of diagnostic value with lower radiation exposure to the patient. The process requires no silver, which is in increasingly short supply.