Department of Endodontics, Fluminense Federal University (UFF), Niteroi, RJ, Brazil.
ZYGO Corporation, Middlefield, CT, USA.
Int Endod J. 2018 Nov;51(11):1271-1278. doi: 10.1111/iej.12936. Epub 2018 May 4.
To evaluate the presence and propagation of defects and their effects on surfaces of nickel-titanium (NiTi) instruments using noncontact, three-dimensional optical profilometry, and to assess the accuracy of this method of investigation.
The flute surface areas of instruments from two commercial instrumentation systems, namely Reciproc R25 (n = 5) and WaveOne Primary (n = 5), were assessed and compared before and after performing two instrumentation cycles in simulated root canals in clear resin blocks. All the analyses were conducted on areas measuring 211 × 211 μm, located 3 mm from the tips of the instruments. A quantitative analysis was conducted before and after the first and second instrumentation cycles, using the Sa (average roughness over the measurement field), Sq (root mean square roughness) and Sz (average height over the measurement field) amplitude parameters. All the data were submitted to statistical analysis at a 5% level of significance.
There was a significant increase (P = 0.007) in wear in both groups, especially between baseline and the second instrumentation cycle, with significantly higher wear values being observed on WaveOne instruments (Sz median values = 33.68 and 2.89 μm, respectively, for WO and RP groups). A significant increase in surface roughness (P = 0.016 and P = 0.008, respectively, for Sa and Sq) was observed in both groups from the first to the second instrumentation cycle, mostly in WaveOne specimens. Qualitative analysis revealed a greater number of defects on the flute topography of all the instruments after use.
More defects were identified in WaveOne Primary instruments compared to Reciproc R25, irrespective of the evaluation stage. The investigation method provided an accurate, repeatable and reproducible assessment of NiTi instruments at different time-points.
使用非接触式三维光学轮廓仪评估镍钛（NiTi）器械表面缺陷的存在和传播情况及其对表面的影响，并评估该研究方法的准确性。
在模拟根管中，使用两种商业器械系统（Reciproc R25，n=5；WaveOne Primary，n=5），在器械进行两个预备循环前后，评估并比较器械的管腔表面区域，并将其与透明树脂块中进行比较。所有分析均在距器械尖端 3mm 处的 211×211μm 测量区域进行。在第一个和第二个预备循环前后，使用 Sa（测量区域的平均粗糙度）、Sq（均方根粗糙度）和 Sz（测量区域的平均高度）幅度参数进行定量分析。所有数据均在 5%的显著性水平下进行统计分析。
两组器械的磨损均显著增加（P=0.007），尤其是在基线和第二个预备循环之间，WaveOne 器械的磨损值显著更高（Sz 中位数值分别为 33.68 和 2.89μm，分别为 WO 和 RP 组）。两组器械的表面粗糙度从第一个预备循环到第二个预备循环均显著增加（Sa 和 Sq 分别为 P=0.016 和 P=0.008），尤其是 WaveOne 器械。定性分析显示，所有器械使用后的管腔形貌均有更多缺陷。
与 Reciproc R25 相比，WaveOne Primary 器械无论在哪个评估阶段，均检测到更多缺陷。该研究方法可在不同时间点对 NiTi 器械进行准确、可重复和重现性的评估。
