title: Artefacts due to static electricity in a dental school.
abstract: The diagnostic usefulness of radiographs is diminished by errors of film handling, and retakes mean increased radiation doses. Avoiding artefacts due to static electricity is part of a quality assurance programme. The number of types of artefacts originating from static electricity in the Department of Radiology, School of Dentistry, Copenhagen, were recorded over a five-week period with low temperatures and low air humidity. During the period 3137 intra-oral and 638 extra-oral films were processed by seven assistants and a number of trainees. A total of 48 artefacts on 47 extra-oral films was observed. The artefacts were classified into four types. Only one case of classical 'lightning' was found, while nine were of a hitherto undescribed type ('animals' or 'cactus flowers'). The most common type appeared as dots arranged in straight lines; their origin was obscure, but it was suspected that they were caused by the processing machine. The one typical 'lightning' case occurred on a Status-X film, consistent with the theory that friction may be a causative factor. Although individual frequencies varied, all the radiography assistants and trainees were associated with the artefacts recorded.
authors.affiliation: Department of Radiology, School of Dentistry, Faculty of Health Science, University of Copenhagen, Denmark.
authors.forename: I P
authors.initials: IP
authors.lastname: Sewerin
mesh_terms: D016477:Artifacts; D011861:Radiography, Dental; D015203:Reproducibility of Results; D012575:Schools, Dental; D055672:Static Electricity; D014962:X-Ray Film