[Radiologic exposure of the dental patient: comparison of the doses delivered by different techniques]

This paper evaluates the doses delivered to the patient during several radiological procedures in dentistry: intraoral, panoramic and cephalometric radiography. Different digital techniques now available are compared to the AgBr film and film-screen technique. Absorbed doses at different organs are derived from measurements on dental radiological phantoms. The largest dose reductions are observed for intraoral radiography (31-84%). Significant dose reductions are also found for panoramic and cephalometric radiography (25-70% and 30-60%, respectively). By optimizing the exposure parameters and according to the ALARA principle, the smallest doses should be delivered to the patient that are needed to achieve the required quality of the images. Independently on the technique, the beam size should match as closely as possible the size of the detector. Collimation is particularly important for intraoral radiography. The dose at the thyroid should be kept as low as possible especially for children. For some beam incidences, a thyroid shield is especially efficient. The development of digital radiography and the related advantages should not lead to increasing the number of radiographs. The prescribed and performed types of examinations, and their number, should always be selected based on the clinical situation and on sound clinical judgment and experience in order to solve the raised medical problem.