Does the radiographic image format influence the detection of fractured endodontic instruments in gutta-percha-filled canals?

OBJECTIVE: To evaluate the influence of different image file formats on the accuracy of detecting fractured endodontic instruments in gutta-percha-filled root canals. METHODS: Thirty-two mandibular molars were instrumented and divided into two groups: case (n = 15), which received a 2 mm fragment of a #35 K-file inside the mesial canal, and control (n = 17), without the fragment. Subsequently, all canals received gutta-percha, and each tooth was placed into a dry human mandible for acquiring radiographs. The radiographs were exported in TIFF, JPEG, BMP, PNG, and DICOM formats, resulting in 160 images (32 radiographs × 5 formats). Six radiologists evaluated the radiographs using a 5-point scale to determine the presence or absence of the fractured instrument. Area under the ROC curve, sensitivity, and specificity were calculated for each evaluator, along with a one-way ANOVA to compare the formats, adopting a 5% significance level. RESULTS: The image file format did not significantly influence the accuracy (p = 767), sensitivity (0.307), or specificity (0.999) in detecting fractured endodontic instruments in filled canals. CONCLUSIONS: The study showed similar performance across the image file formats tested for detecting fractured instruments. These results suggest that commonly used and compatible formats can be used without compromising diagnostic accuracy. ADVANCES IN KNOWLEDGE: Instrument fracture is one of the most challenging complications in endodontic treatments, and digital periapical radiographs are widely used in diagnosing this occurrence. The detection and localization of the fragment inside the canal are essential for a favorable prognosis.