(PO121) Micro–Computed Tomographic Evaluation of Shaping Ability by Novice Dental Students with 3 Reciprocating File Systems; WaveOne Gold, ESR and EdgeOne Fire

Abstract: A previous study by our group reported that novice dental students preferred the reciprocating system over the rotation system, which showed less canal transportation and better centering ability. This study aimed to examine the shaping ability of novice dental students with three reciprocation file systems and their preference after use. Mesial canals of 42 3D-printed mandibular first molars (TrueTooth, PlanBDental) were instrumented with WaveOne Gold (WOG), ESR, and EdgeOne Fire (EOF) by 14 sophomore dental students. Micro-computed tomography was used to scan teeth before and after instrumentation to compare canal transportation and centering ratio at the apical, middle, and coronal levels. Total instrumentation time was also recorded. A questionnaire was completed regarding students’ perception with a 5-point Likert scale: ease of use, flexibility, cutting efficiency, screwing effect, and overall impression. Their preference was also asked. Statistical analysis was completed using one-way repeated measures ANOVA with the Bonferroni test (p < .05). ESR showed significantly more canal transportation and worse centering ratio than WOG and EOF at the apical thirds of the mesio-buccal canal. EOF showed a better centering ratio than WOG and ESR at the coronal thirds of the mesio-buccal canal. EOF also showed less canal transportation than WOG and ESR, and a better centering ratio than WOG at the middle thirds of the mesio-lingual canal (p < .05). While instrumentation times were not significantly different, 9 out of 14 students (64.2%) preferred EOF, which had significantly higher scores for “ease of use” and “flexibility.” EOF produced better centering ratios and less canal transportation than other reciprocating systems and was preferred by novice dental students.