[Shaping ability of two nickel-titanium rotary systems in simulated S-shaped canals].
OBJECTIVE
To evaluate the shaping ability of two nickel-titanium rotary systems (ProTaper and Hero642) in simulated S-shaped canals.


METHODS
Thirty simulated S-shaped canals were randomly divided into three groups and prepared by ProTaper, Hero642, ProTaper combined with Hero642 respectively. All the canals were scanned before and after instrumentation, and the amount of material removed in the inner and outer wall and the canal width after instrumentation were measured with a computer image analysis program.


RESULTS
There was significant difference in the amount of material removed at the inner side of apical curvature and outer side of apex between ProTaper combined with Hero642 and ProTaper files (P < 0.05) at the same tip size. The inner and outer wall of the canals were evenly prepared by ProTaper combined with Hero642, and the taper of canals were better than those prepared by Hero642.


CONCLUSIONS
ProTaper combined with Hero 642 had better shaping ability to maintain the original shape and could create good taper canals in the simulated S-shaped canal model.
Luo
Hong-xia
HX
Department of Cariology and Endodontology, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
Huang
Ding-ming
DM
Zhang
Fu-hua
FH
Tan
Hong
H
Zhou
Xue-dong
XD
D003722:Dental Alloys; D003762:Dental Instruments; D003786:Dental Pulp Cavity; D004868:Equipment Failure; D003765:Models, Dental; D009532:Nickel; D016382:Orthodontic Appliance Design; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D014025:Titanium
D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium