Phase transformation behaviors and mechanical properties of NiTi endodontic files after gold heat treatment and blue heat treatment

J Oral Sci. 2020 Dec 23;63(1):8-13. doi: 10.2334/josnusd.19-0331. Epub 2020 Dec 7.

Abstract

WaveOne Gold, ProTaper Gold, Reciproc Blue, ProTaper Next, WaveOne and ProTaper files were selected to compare the phase transformation behaviors and mechanical properties of nickel-titanium (NiTi) rotary files after gold heat and blue heat treatments. The reverse transformation finishing point temperatures of WaveOne Gold, ProTaper Gold, ProTaper Next and WaveOne were higher than those of the other two instruments investigated. At a deflection of 0.5 mm, the loads were significantly varied except for ProTaper Next and ProTaper Gold. At a deflection of 3.0 mm, the loads of Reciproc Blue and WaveOne Gold were significantly varied compared to WaveOne and ProTaper. Cycles to failure were reduced in the order of WaveOne Gold, Reciproc Blue, ProTaper Gold, ProTaper Next, WaveOne and ProTaper. NiTi instruments after gold heat and blue heat treatments exhibited significantly higher bending properties and cyclic fatigue resistances, representing an improved performance over traditional and M-wire instruments.

Keywords: blue heat treatment; gold heat treatment; nickel-titanium; phase transformation; rotary instrument.

MeSH terms

  • Dental Instruments
  • Equipment Design
  • Gold
  • Hot Temperature
  • Materials Testing
  • Nickel*
  • Root Canal Preparation
  • Titanium*

Substances

  • Gold
  • Nickel
  • Titanium