Comparison of preparation errors among dental students in different study years in the endodontic department of dentistry faculty of Birjand, Iran, during 2014-2017

Traumas to the teeth can damage the pulp that may require root canal treatment. In addition, the evaluation of trauma errors is very important in every educational system. Therefore, the aim of the present study was to investigate technical errors during root canal therapy and compare these errors among the students who were in their 4th, 5th, and 6th years of their education in Dental Faculty of Birjand, Iran. Methods: A total of 428 documents of root canal therapy performed by dental students who were in the 4th, 5th, and 6th years of their education were randomly selected during 2014-2017. For each tooth, four radiographs, including the periapical images of the initial radiograph, master apical file, master cone, and final obturation radiographs, were reviewed under the supervision of an endodontist. Technical errors investigated included transport, ledge, perforation, underfilling, overfilling, and presence of void and broken instrument. The data were entered into a relevant form and analyzed. The normality was investigated using the Shapiro-Wilk test in the SPSS commercial software (version 22). In the present analysis, because the normality of the data was not confirmed, the Kruskal-Wallis and Mann-Whitney U tests were used, and the Chi-Square test was also utilized at the α-level of 0.05 to compare the ratio. Results: Technical errors were observed in 149 out of 428 documents (34.8%). Numbers of the documents containing technical errors were 60 (30.6%), 78 (40.6%), and 11 (27.5%) associated with the students of the 4th, 5th, and 6th years, respectively. Only one perforation error was observed by the students of the 5th year. In addition, there was no transport error by the students of the 4th year. Number of the ledge and overfilling errors presented significant differences by the students of various years (Pledge=0.01 and Poverfill=0.002). Conclusions: Results of this study showed that 65.2% of the students had acceptable performance; however, procedural errors were a fairly common finding among the students. Moreover, there were significant differences between students in different years. Pre-evaluation of radiographs and more accurate case selection could promote the quality of root canal therapy among students.