Defects in EndoSequence new Instruments : A SEM Study (Pilot Study)

Nickel-titanium rotary (NTR) instruments have gained widespread acceptance in root canal therapy in the past decade, but require frequent replacement. EndoSequence is a recently developed NTR (ENTR) file. The objective: of this study was to evaluate the chemical composition of the new instruments and the presence of microfractures by scanning electron microscopy (SEM).

Methods: This study was conducted using a set of 4 ENTR files 21-mm, .06 taper as follows: 40/.06, 35/.06, 30/.06, 25/.06. All instruments were cleaned in ultrasonic dish in order to completely eliminate any residue that may have remained attached in ultrasonic dish in order to cpletely eliminate any residue that may have remained attached to the surface of the blades. The instruments were evalued in D0, D1, D2 and D3 by SEM as to energy-dispersive x-ray spectrometer (EDS). The mean and standard deviations were determined.

Results: SEM examination of new files showing the next results: Microfractures presents in all instruments, disruption of cutting edge in all samples, craters in 75% and blunt edge in 25% of the sample. Pitting was observed in instruments 30/.06, 35/.06 in all millimeters (2000X). SD 2.4023 (Ni), SD 0.1173 (Ti).

Conclusions: Under the conditions of this study, electropolishing did not inhibit the development of microfractures in ENTR files.