Detection of approximal caries with a storage phosphor system. A comparison of enhanced digital images with dental X-ray film

Objectives. To compare the accuracy of approximal caries detection using enhanced and unenhanced storage phosphor images and dental X-ray film. Methods. Fifty premolar/molar teeth were exposed simultaneously under standardized conditions on storage phosphor (SP) image plates (Digora(R)) and Ektaspeed film, The image files were transferred to a different platform for image processing. Using a five-paint confidence scale, ten observers rated 95 approximal surfaces for caries in enamel and dentin with three image modalities: enhanced and unenhanced SP images and film. The observations were validated microscopically. Diagnostic accuracy was measured as the area beneath the ROC curve (A(z)). Results. Enhanced SP images had significantly higher A(z) values in both enamel (A(z) = 0.819) and dentin (A(z) = 0.845) than unenhanced images and film. No significant differences were found in either enamel or dentin between unenhanced SP images (A(z) = 0.780 and A(z) = 0.789) and film (A(z) = 0.688 and A(z) = 0.793). Conclusion. Enhancement of storage phosphor images improved detection of approximal caries in this in vitro study compared with unenhanced images and Ektaspeed film. Copyright (C) 1996 Elsevier Science Ltd for the IADMFR.