Influence of Enhancement Filter Application in Panoramic Radiographs in the Detection of External Root Resorption in Mandibular Second Molars Caused by Impacted Third Molars.

To evaluate the influence of enhancement filters on panoramic radiographs for the detection of external root resorption (ERR) in lower second molars caused by impacted third molars. One hundred and twenty-four panoramic radiographs with 182 lower third molars were selected. The corresponding cone-beam computed tomography scans were assessed to create the reference standard. The panoramic radiographs were then exported with and without four enhancement filters (Sharpness, Invert, Invert + Sharpness, and Equalized + Magnification) and independently evaluated by five examiners using a five-point scale for ERR presence. The area under the ROC curve (AUC), sensitivity, and specificity were calculated, and differences between filters were analyzed using ANOVA and Tukey's test. Intra- and inter-examiner agreements were assessed using weighted Kappa index. Diagnostic values were similar across filters for AUC (0.56 to 0.61; p = 0.359), but sensitivity was lower (0.25 to 0.50; p = 0.004) and specificity higher (p = 0.002) for the Invert and Invert + Sharpness filters than for the other situations. Intra-examiner agreement was moderate, while inter-examiner agreement was fair. The diagnostic accuracy of ERR in mandibular second molars on panoramic radiographs is unaffected by filters, but sensitivity decreases with Invert and Invert + Sharpness filters.