technical quality of root canal therapies performed by novice dental students in preclinical practice

background: for improving the quality of endodontic performance of practitioners in clinical practice, their basic, preclinical performance and knowledge must be taken into consideration. this study aimed to radiographically evaluate the technical quality of preclinical molar root canal treatments (rcts) performed by undergraduate dental students at a dental school in iran. further, the effect of using gates-glidden (gg) drills on the fi nal quality of rcts was evaluated. materials and methods: in this retrospective cross-sectional study, 315 roots of 105 endodontically treated teeth in preclinical practice were evaluated radiographically. the analyzed quality parameters included length, taper and density of fi llings, which were scored as s2 (adequate standard), the s1 (slight deviation), or s0 (considerable deviation). for all the parameters, acceptable, moderate and poor fi llings received total scores of 6, 3-5 and 0-2, respectively. there were two groups of students: one group had used only k-fi les, and the other had used k-fi les along with gg drills. the quality of rcts between these groups was evaluated using the aforementioned scoring protocol. the results were analyzed using chi-square, mann–whitney and fisher’s exact tests (α = 0.05). results: under-fi llings (p = 0.001) and under-shapings (p = 0.007) occurred mostly in mandibular root fi llings. a lower density was found in maxillary fi llings (p < 0.001). no relationship was observed between the technique used (irrespective of gg drills usage) and length (p = 0.499) and taper of fillings (p = 0.238). the roots instrumented with gg drills had a higher fi lling density (p = 0.004). the quality mean score of rcts was improved when gg drills were used (p = 0.008). conclusion: the technical quality of preclinical molar rcts performed by undergraduate dental students was considered acceptable in 35.6% of the cases. when gg drills were used along with k-fi les, the technical quality of rcts was enhanced. key words: dental, dental student, education, endodontics, root canal therapy