Int Poster J Dent Oral Med 5 (2003), No. 2 15. June 2003
Int Poster J Dent Oral Med 5 (2003), No. 2 (15.06.2003)
Poster 171, Language: German
Einfluss digitaler Filter auf die Messung der Tiefe approximaler Karies
Koob, Andreas/Sanden, Etje/Staehle, Hans Jörg/Haßfeld, Stefan/Eickholz, Peter
Objectives: The aim of this study was to assess of the effects of different image processing modes (filters) on the reproducibility and accuracy of the assessment of proximal carious lesions viewed in direct digital radiographs. Variables studied were exposure time and tissue scatter radiation. Methods: Standardized direct digital radiographs of 50 extracted teeth were obtained and 44 areas of proximal caries were detected histologically. Four radiographs were obtained of each tooth using a charge coupled device sensor. Two radiographs were obtained with and 2 without tissue scatter radiation equivalent (TSRE) each of them at normal exposure time (0.06 s) and underexposed (0.01 s). On each of the 200 radiographs, the central depth (CD) of each carious lesion was measured at 21fold magnification both on the unchanged image and af-ter use of 2 different filters (median, median plus inversion). All measurements were re-peated after one week to estimate reproducibility. Histometric CD assessments provided a gold standard for compari-son with the radiographic measurements (accuracy). Results: Whereas reproducibility was not influenced significantly by any of the investigated parameters, defect type and exposure time influenced the overall accuracy of CD measurements. Conclusions: In this study, basic digital filtering of radiographic images failed to result in statis-tically significant improvement of the accuracy of CD measurements.
Applied to caries monitoring direct digital radiographs using the investigated CCD sensor are equivalent to E speed conventional films. Basic digital filtering fails to adjust for further reduction of exposure time.
Keywords: direktes digitales Röntgen, Diagnostik der Approximalkaries, digitale Filter
Jahrestagung der Deutschen Gesellschaft für Zahn-, Mund- und Kieferheilkunde