Abstract
BACKGROUND: Endodontic success relies heavily on the accurate shaping and cleaning of root canals, especially in curved canals where procedural errors like canal transportation can occur. Instrument design, alloy flexibility, and taper significantly influence canal shaping outcomes. MATERIALS AND METHODS: A total of 102 extracted mandibular molars with uncalcified, noncarious mesiobuccal canals were selected. Teeth were divided into three groups: Group I (K-file), Group II (NeoEndo S rotary), and Group III (GenEndo rotary). After access cavity preparation and initial glide path formation, root canals were prepared to size 25/02 (manual) and 25/04 (rotary). Cone beam computed tomography scans were performed pre- and postinstrumentation at 2, 4, and 6 mm from the apex to assess canal transportation and centering ability using standard formulas. RESULTS: Group I (K-files) showed minimal mesiobuccal (MB) transportation at 2 mm (0.01 ± 0.22 mm) and the highest centering ratio at 2 mm (0.62 ± 0.85). Group II (NeoEndo S) had the highest transportation at 2 mm (MB: [0.10 ± 0.35 mm], DL: [0.51 ± 1.30 mm]) and the lowest centering ability (0.13 ± 1.75). At 4 mm, NeoEndo S again showed maximum transportation ([0.06 ± 0.35] MB, [0.53 ± 0.93] DL) compared to GenEndo and K-files. At 6 mm, Group III (GenEndo) showed greater MB transportation (0.31 ± 0.54 mm) and the lowest centering ability (0.01 ± 0.83). ANOVA revealed no significant differences for MB and DL transportation (P > 0.05 across groups), but centering ability differed significantly in Group III (P = 0.023), particularly between 2 and 4 mm distances. CONCLUSION: All tested instruments caused some degree of canal transportation. GenEndo files demonstrated better centering ability and less canal deviation compared to NeoEndo S and K-files, attributed to their design and alloy properties.