In previous decades, root canal shaping was primarily achieved with manual stainless steel files. The development of nickel–titanium (NiTi) mechanical instruments has since offered the potential for more efficient and predictable canal preparation. Despite these advancements, the use of NiTi systems in undergraduate training remains limited. This study aimed to compare three root canal preparation approaches—manual instrumentation using stainless steel hand files, continuous rotary motion with ProTaper Gold (PTG) files, and reciprocating motion with WaveOne Gold (WOG) files—on endodontic resin blocks, evaluating both preparation quality and instrumentation time. Thirty-six third-year dental students with no prior endodontic experience were randomly assigned to six groups to prepare 108 resin blocks, each student working on three. Standardized photographs were obtained at preoperative, intraoperative, and postoperative stages to analyze resin removal, apical transportation, and mid-cervical wear. Additionally, questionnaires were distributed to assess students’ satisfaction and subjective experiences. Data were analyzed using the Friedman test, Wilcoxon test with Bonferroni correction, and Kruskal–Wallis test followed by the Mann–Whitney U test, with statistical significance set at p < 0.05.
The PTG group demonstrated significantly less apical deviation (0.073 ± 0.003) than both the WOG and manual groups (p < 0.001). A significant difference in mid-cervical wear was noted only between PTG and manual techniques. Manual instrumentation showed greater inconsistency and required approximately five times longer to complete. Overall, 90% of students preferred mechanical over manual instrumentation. Mechanical systems, especially the PTG, were markedly faster and produced superior canal shaping quality. These findings support the integration of mechanical instrumentation into undergraduate dental curricula.
