ABSTRACT
Objective:To evaluate the shaping effects of multi-taper ProTaper combined with nickel-titanium(Ni-Ti) K file in simulated S-shaped canals. Methods:Thirty simulated S-shaped resinous canals were randomly divided into three groups and prepared with hand ProTaper, hand Ni-Ti K file, hand ProTaper combined with Ni-Ti K file respectively. The shaping effects were assessed by the amount of material removed from the inner and outer wall of canal as well as the width of canal after instrumentation. Results: The shaping files of ProTaper removed the least material in amount of materials from the same apical dimension. The finishing files of ProTaper removed the most amount of material at the inner side of curvature and outer side of apex. ProTaper combined with Ni-Ti K file removed the least material at the above parts and the widths of canals prepared were gradually decreased from the orifice to the apex. Conclusion:ProTaper combined with Ni-Ti K file exhibited good shaping effects in simulated S-shaped canals.