Radiographic evaluation is a simple and reliable way to assess the technical quality of root canal treatment. This study investigates the extent to which undergraduate dental students’ use of periapical radiographs to evaluate root canal filling quality conforms with a gold standard of evaluation established by expert endodontists; it also assesses their perceived confidence and self-reported estimated disagreement ranges (sEDR). A total of 107 students evaluated 60 periapical radiographs using four predefined criteria for root canal filling quality: length, density, taper and procedural errors. The evaluations of four experienced endodontists established a “gold standard” that was used as the reference for assessing the extent to which students’ evaluations of each periapical radiograph agreed with predefined criteria. Perceived confidence and sEDR were also recorded. Students’ agreement with the gold standard was assessed using Cohen’s kappa (κ); diagnostic performance was assessed using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The significance level was set at p 0.05). For length, density and taper, fifth-year students showed higher sensitivity, PPV and NPV; whereas specificity was higher in fourth-year students. Dental students demonstrated limited proficiency in radiographic evaluation of root canal filling quality, and their performance was independent of academic year, perceived confidence and sEDR. Clinical experience appears to improve recognition of non-ideal root canal fillings, whereas earlier training appears to improve recognition of ideal ones. Notably, perceived confidence and sEDR varied by academic year.
Tezer et al. (2026) studied this question.