Characterization of Phase Transformations and Chemical Composition in Rotary and Reciprocating Nickel-Titanium Endodontic Instruments

Abstract

Background: The mechanical stresses to which the files are subjected differ depending on the type of movement. Therefore, the flexibility and resistance of the instruments must vary according to clinical needs. Which depends on the chemical composition and thermal treatment of the material, which gives it the atomic arrangement.

Objectives: Analyze the physical, chemical and thermal properties of rotary and reciprocating instruments.

Methods: The reciprocating and rotary instrumentation systems: WaveOne Gold, Reciproc Blue, Vortex Blue and V-Taper were evaluated under SEM, as well as their chemical composition by ICP-OES analysis, the phase transitions through DSC, and structurally by X-ray diffraction.

Results: Chemical analysis determined that the NiTi alloys, corresponding to Vortex Blue and V-Taper 2H, have an almost 1:1 Ni:Ti atomic ratio, but with a significant variation in the Ni content. Likewise, a low Au content was detected in the alternative WaveOne Gold system. Regarding the thermal analysis, the alternative V-taper 2H system showed a double exothermic transition associated with an intermediate rhombohedral phase known as R phase. The diffraction patterns show the transition of the austenitic phase.

Conclusions: Thermochemical analysis, Rotary Instruments, Reciproc Blue, Vortex Blue, V-Taper 2H, and WaveOne Gold.

Keywords:

Nutrition, Therapy, Cancer management, Oncology

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