Objectives: To examine the effects of the luminance and bit depth of digital image on observer performance for determination of endodontic file positioning.
Study design: Using extracted premolar teeth, no. 08 K-file was placed into the canal and positioned so that the tip was either flush or 1 mm short of the radiologic root apex. The samples were imaged with both conventional and digital radiographs at 8 and 12 bits. Eleven observers read the images under dark and bright condition, and receiver operating characteristics analysis was performed. Additionally, the interpreting time was measured.
Results: The 12-bit images showed similar observer performance compared with conventional images, and better than the 8-bit images. The interpretation time for bright condition and 8-bit images was longer than for dark condition and 12-bit images.
Conclusion: Twelve-bit digital images were preferred to 8-bit for accurate determination of endodontic file position.