Laboratory comparison of the mechanical properties of TRUShape with several nickel-titanium rotary instruments.
OBJECTIVE
To assess and compare the mechanical properties of TRUShape (TRS) with several nickel-titanium rotary instruments.


METHODS
Cyclic fatigue, torsional resistance, flexibility and surface microhardness of TRS (size 25, 0.06v taper), ProTaper Next X2 (PTN X2, size 25, 0.06 taper), ProTaper Gold (PTG F2; size 25, 0.08 taper) and ProTaper Universal (PTU F2; size 25, 0.08 taper) instruments were evaluated. The topographical structures of the fracture surfaces of instruments were assessed using a scanning electron microscope. The cyclic fatigue resistance, torsional resistance and microhardness data were analysed using one-way analysis of variance (anova) and Tukey's post hoc tests. The fragment length and bending resistance data were analysed statistically with the Kruskal-Wallis H-test and Mann-Whitney U-tests. The statistical significance level was set at P < 0.05.


RESULTS
PTN and PTG instruments revealed significantly higher resistance to cyclic fatigue than TRS and PTU instruments (P < 0.001). PTN instruments revealed significantly higher torsional resistance compared with the other instruments (P < 0.001). PTG instrument had significantly higher flexibility than the other tested brands (P < 0.05). However, for microhardness, the PTU had significantly higher surface microhardness values compared with other tested brands (P < 0.05).


CONCLUSIONS
TRS instruments had lower resistance to cyclic fatigue and lower flexibility compared with PTG and PTN instruments. TRS, PTG and PTU instruments had lower resistance to torsional stress than PTN instruments. TRS and PTG instruments had comparable surface microhardness.
Department of Endodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
A M
AM
Elnaghy
Department of Dental Biomaterials, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
S E
http://orcid.org/0000-0002-7525-1379
SE
Elsaka
D003722:Dental Alloys; D006801:Humans; D008422:Materials Testing; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium; D054159:Torsion, Mechanical
D003722:Dental Alloys; D009532:Nickel; D014025:Titanium
ProTaper Gold; ProTaper Next; ProTaper Universal; TRUShape; mechanical properties