Method and Material: A total of 40 mesiobuccal root canals of human mandibular first molars with an angle of curvature of 25-35 degrees and radius curvature of 5 millimeters were randomly divided into two groups of 20 canals each. Group A was prepared with Pro Taper Gold and Group B with V Taper Blue. Pre- and post-instrument CBCT scans were recorded. Images were reconstructed and cross-sections were detected corresponding to distances 3, 6, and 9 mm from the anatomic apex using Gambill’s method. Statistical analysis was performed with T-test and repeated measure ANOVA. P-value was set at 0.05.

Results: No significant difference was observed among Pro Taper Gold and V Taper Blue in terms of centering ability from mesiodistal (P=0.304) and buccolingual (0.632) directions. Also, there was no statistical difference across two different instruments in considering to canal transportation from mesiodistal (P=0.581) and buccolingual (P=0.259) directions. However, in centering ability evaluation, each of the two groups showed significant differences in various levels of coronal, middle, and apical root level (P=0.000).

Conclusion: The two instruments were similar in terms of centering ability and canal transportation in mandibular curved canal preparation.