in vitro transportation of curved canals following glide path preparation by path file and scout race rotary systems versus manual instrumentation using cone-beam computed tomography

Objectives: this study aimed to assess root canal transportation of curved canals following glide path preparation by pathfile and scout race rotary systems compared with manual instrumentation with stainless steel (ss) hand files using cone-beam computed tomography (cbct). materials and methods: this in-vitro experimental study was conducted on extracted human mandibular first and second molars (n=51) with 25-45° canal curvature in their mesiobuccal root. all teeth underwent cbct and were randomly divided into three groups (n=17). in group 1, a glide path in the mesiobuccal canal was created using ss hand files to the working length. in groups 2 and 3, after canal negotiation with a #8 ss hand file, a glide path was created with pathfile and scout race systems, respectively. the teeth underwent cbct. pre- and postoperative cbct scans were compared to calculate the magnitude of canal transportation at 3, 6, and 9 mm from the apex. the results were analyzed using the kruskal-wallis and freedman tests (p<0.05). results: manual instrumentation caused significantly higher canal transportation at 3 and 9 mm from the apex compared with rotary systems (p<0.05). pathfile and scout race were not significantly different at 3 (p=0.39) or 9 mm (p=0.99). no significant difference was noted in canal transportation among the three groups at 6 mm (p=0.15). conclusion: scout race and pathfile cause less canal transportation than manual instrumentation with ss files when used for glide path preparation in curved canals, especially in the apical third.