The influence of heat treatment on the mechanical properties of Ni-Ti file materials.
The purpose of this study was to investigate the influence of heat treatment on the mechanical properties of Ni-Ti file materials. Ni-Ti wire (1.00 mm ø) was processed into a conical shape with 0.30-mm diameter tip and 0.06 taper. Specimens were heated for 30 min at 300, 400, 450, 500 or 600°C. Non-heated specimens were used as controls. DSC, a cantilever-bending test and cyclic fatigue test were performed. Ms and Af for groups 400 and 450 were higher than those for others (p<0.05). The load/deflection ratios of groups 400, 450 and 500 were lower than that of group 600 (p<0.05). The bending load values at 2.0-mm deflection of groups 400, 450 and 500 were lower than those of group 300 and the control group (p<0.05). The NCFs of groups 400, 450 and 500 exceeded that of group 600(p<0.05). Changes in flexibility with heat treatment could improve the cyclic fatigue properties of Ni-Ti instruments.
Pulp Biology and Endodontics, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.
Kana
K
Miyara
Yoshio
Y
Yahata
Yohsuke
Y
Hayashi
Yusuke
Y
Tsutsumi
Arata
A
Ebihara
Takao
T
Hanawa
Hideaki
H
Suda
D002152:Calorimetry, Differential Scanning; D003799:Dental Stress Analysis / Q000379:methods*; D004548:Elasticity; D006358:Hot Temperature; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry*; D018583:Pliability; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium / Q000737:chemistry*
C040654:titanium nickelide; D009532:Nickel; D014025:Titanium