Digital imaging filters and their effect on detecting apical root resorption

Abstract

<h3>Objective</h3> To assess differences in the detection of apical root resorption using different imaging software filters in digital radiographs. <h3>Study Design</h3> In total, 29 teeth were evaluated for this study using CMOS digital x-ray images. The radiographs consisted of teeth with and without root resorption, verified through cone beam CT imaging. A common dental imaging software was used to create four different images using the following built-in filters: invert, edge enhance, dentin-to-enamel junction (D to E), and endo (E), plus the original unfiltered image. Three dental students individually scored the 145 images for the presence or absence of root resorption with a 5-point grading scale: 1) absent, 2) probably absent, 3) uncertain, 4) probably present, and 5) present. Intra- and interobserver agreement was calculated by using the weighted kappa test. Receiver operating characteristic (ROC) analysis was performed, and diagnostic accuracy was represented by the area under the curve (AUC) with 95% confidence intervals (CI). Diagnosis values were compared by a two-way ANOVA, with post-hoc Tukey test. The level of significance was established at P<0.05. The Institutional Review Board approved this project (IRB #5180360). <h3>Results</h3> The greatest accuracy was achieved with the ‘Endo' filter (AUC=.950; 95%CI: .869 - .1.0). The ‘D to E' filter yielded the least accurate ROC value (AUC =.758; 95%CI: .551 - .965)<b>.</b> <h3>Conclusions</h3> Imaging filters can affect diagnosis of root resorption depending on which type of filter is applied. With this in mind, judicious usage is suggested to achieve optimum outcomes and advanced imaging may be warranted in certain circumstances. <b>Statement of Ethical Review</b> Human/Animal subjects were used and this study was approved by an institutional ethics panel