Diagnostic accuracy of intraoral film and direct digital images for detection of simulated recurrent decay

This study compared the diagnostic accuracy of bitewing images for detection of simulated recurrent caries using the following imaging modalities: Ektaspeed Plus film and different digital imaging system technologies comprised of a charge-coupled device (CCD) based digital imaging unit, a photo-stimulable phosphor (PSP) based unit and contrast-and brightness-enhanced PSP images. Study Design: Twenty-four extracted posterior teeth with MOD inlay preparations were secured in models simulating a natural arrangement of teeth. Lesions were created in proximal boxes using dental burs of varying sizes. Defects were filled with wax and plaster and preparations were restored with composite or amalgam. Results: Averages of receiver operating curve areas (A(2)) revealed diagnostic performances of Az=0.74 for film, Az=0.80 for CCD, Az=0.73 for unenhanced PSP and Az=0.64 for enhanced PSP. The differences between these means were significant (MANOVA p <0.0001). Unenhanced PSP produced significantly poorer performance than other modalities. CCD performance was not significantly better than enhanced PSP. Lesions under radiopaque composite restorations were easier to detect, followed by those under amalgam and radiolucent composites across imaging modalities and lesion locations. Based on lesion location, those located at the buccal point angle were easiest to detect, followed by those at midgingival floor and lingual-point angle sites. Conclusions: Contrast and brightness-enhanced digital images enabled better signal detection and a comparable performance with film for detection of artificially induced recurrent caries.