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

Abstract

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) and Ektaspeed film. The image files were transferred to a different platform for image processing. Using a five-point 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 (Az).

Results: Enhanced SP images had significantly higher Az values in both enamel (Az = 0.819) and dentin (Az = 0.845) than unenhanced images and film. No significant differences were found in either enamel or dentin between unenhanced SP images (Az = 0.780 and Az = 0.789) and film (Az = 0.688 and Az = 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.