radiographic evaluation of root canal fillings accomplished by undergraduate dental students

introduction: the purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at tabriz faculty of dentistry between 2006 and 2012. methods and materials: a total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. for each tooth, preoperative, working and postoperative radiographs were checked. the pearson’s chi-square test was used for statistical evaluation of the data. inter-examiner agreement was measured by cohen’s kappa (k) values. the level of significance was set at 0.05. results: total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. there were significant differences between frequencies of over- and under-fillings ( p <0.05). unacceptable quality, under- and over-fillings were detected in 27.9% of 1183 evaluated canals. conclusion: the technical quality of root canal therapies performed by undergraduate dental students using step-back preparation and lateral compaction techniques was unacceptable in almost one-fourth of the cases.