Noncontact three-dimensional evaluation of surface alterations and wear in NiTi endodontic instruments

Abstract

The aim of this study was to undertake a qualitative and quantitative assessment of nanoscale alterations and wear on the surfaces of nickel-titanium (NiTi) endodontic instruments, before and after use, through a high-resolution, noncontact, three-dimensional optical profiler, and to verify the accuracy of the evaluation method. Cutting blade surfaces of two different brands of NiTi endodontic instruments, Reciproc R25 (n = 5) and WaveOne Primary (n = 5), were examined and compared before and after two uses in simulated root canals made in clear resin blocks. The analyses were performed on three-dimensional images which were obtained from surface areas measuring 211 × 211 µm, located 3 mm from their tips. The quantitative evaluation of the samples was conducted before and after the first and second usage, by the recordings of three amplitude parameters. The data were subjected to statistical analysis at a 5% level of significance. The results revealed statistically significant increases in the surface wear of both instruments groups after the second use. The presence of irregularities was found on the surface topography of all the instruments, before and after use. Regardless of the evaluation stage, most of the defects were observed in the WaveOne instruments. The three-dimensional technique was suitable and effective for the accurate investigation of the same surfaces of the instruments in different periods of time.

Centering ability, canal transportation and surface modifications of ProTaper F2 and F3 used in continuous rotation and reciprocating motion in curved root canals

“…Regarding instrument distortions, surface wear and fracture, no statistical differences were found between PT F2 and F3 instruments after 1, 3 and 6 uses, regardless the protocol used. Nevertheless, for some instruments, the number of uses increased spiral distortion and surface wear, agreeing with other studies that investigated the occurrence of defects on NiTi rotary instruments after use 10,34,35,36,37,38 .…”

Defect propagation in NiTi rotary instruments: a noncontact optical profilometry analysis

“…It provides an extended scan range to measure profile heights from <1 nm up to 20 000 μm, with high vertical ( z ‐axis) optical resolution (0.01 nm), 0.4–0.6 μm lateral resolution ( x ‐ and y ‐axes) and a repeatability of 0.02 nm (Z‐scanning) that enables reliable analyses to be made at different time‐points (Ferreira et al . 2017a).…”

“…The method The P-values in bold are significant (P < 0.05). has been considered to provide suitable and accurate nanoscale analysis of NiTi instrument surfaces under various conditions (Lopes et al 2016, Ferreira et al 2017a,b, Uslu et al 2018. It provides an extended scan range to measure profile heights from <1 nm up to 20 000 lm, with high vertical (z-axis) optical resolution (0.01 nm), 0.4-0.6 lm lateral resolution (x-and y-axes) and a repeatability of 0.02 nm (Z-scanning) that enables reliable analyses to be made at different time-points (Ferreira et al 2017a).…”

“…Recently, a three‐dimensional, high‐resolution image analysis of the cutting blades of WaveOne and Reciproc instruments revealed the presence of surface defects, such as deformations, debris, grooves, cracks, steps and microcavities, both before and after use (Ferreira et al . 2017a). The technique is reported to provide accurate reproduction of constructed images over 1900 million data points, permitting full characterization and quantification of surface topographical features such as roughness and wear on the same surface areas at different time periods (Ferreira et al .…”

A Radiographic Comparison of Two Methods of Hand and Automated Instrumentation for Preparations of Simulated Curved Root Canals

“…However, during instrumentation of the root canals we may have undesirable intercurrences such as deviation of the original channel path, tread formation, zips and perforation. In order to reduce the undesirable effects produced during root canal instrumentation, the endodontic instruments have undergone alterations such as modification in their cross section, penetration guide, taper, increase of diameter and material used for their preparation with the introduction of nickel alloy (Sydney et al, 2001;Amaral et al, 2003;Ferreira et al, 2017).…”