Department of Endodontics, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal.
Unidade de Investigação em Ciências Orais e Biomédicas (UICOB), Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal.
Int Endod J. 2021 Sep;54(9):1623-1637. doi: 10.1111/iej.13529. Epub 2021 May 5.
To compare six reciprocating instruments regarding their geometric design, metallurgical characteristics, mechanical behaviour and ability to prepare root canals.
A total of 246 new 25-mm NiTi instruments (41 per group) from six reciprocating systems (Reciproc, Reciproc Blue, One Files, One Files Blue, Reverso Silver, and WaveOne Gold) were evaluated throughout a multimethod approach regarding their design using stereomicroscopy (number of blades and helix angle) and scanning electron microscopy (blades symmetry, cross section and surface finishing), nickel-titanium composition, phase transformation temperatures, mechanical performance (cyclic fatigue, torsional and bending resistance) and unprepared canal surface area on anatomically matched mandibular molars assessed by micro-CT. One-way ANOVA and post hoc Tukey's or Mood's median tests were selected depending on sample distribution with significance level set at 5%.
The instruments had similarities regarding their metal composition and unprepared canal area, whilst differences in phase transformation temperatures and geometric design (number of blades, surface finishing and tip geometry) were observed. Overall, no difference was observed regarding the maximum torque values (P > 0.05), whilst One Files (72 s) and One Files Blue (414 s) had the shortest and longest times to fracture, respectively (P < 0.05). Similar angles of rotation were observed in Reciproc (310°), One Files (285°) and Reverso Silver (318°) instruments (P > 0.05), which were significantly lower than Reciproc Blue (492°), One Files Blue (456°) and WaveOne Gold (492°; P < 0.05). Maximum bending load demonstrated that Reciproc Blue (201.3 gf) was significantly more flexible that the other instruments (P < 0.05).
Although there were similarities in metal composition and percentage of unprepared canal surface, the instruments had differences in the overall geometric design, phase transformation temperatures and in the four mechanical resistance parameters (time to fracture, maximum torque, angle of rotation and maximum bending load).
比较 6 种往复式器械在几何设计、冶金特性、机械性能和根管预备能力方面的差异。
通过立体显微镜（叶片数量和螺旋角）和扫描电子显微镜（叶片对称性、横截面和表面光洁度）评估来自 6 种往复式器械（Reciproc、Reciproc Blue、One Files、One Files Blue、Reverso Silver 和 WaveOne Gold）的 246 个全新 25-mm NiTi 器械（每组 41 个）的设计，使用多方法评估其镍钛成分、相变温度、机械性能（循环疲劳、扭转和弯曲阻力）和使用微 CT 评估解剖匹配下颌磨牙的未预备根管表面面积。根据样本分布选择单因素方差分析和事后 Tukey 或 Mood 中位数检验，显著性水平设为 5%。
这些器械在金属成分和未预备根管面积方面具有相似性，而在相变温度和几何设计（叶片数量、表面光洁度和尖端几何形状）方面存在差异。总体而言，最大扭矩值没有差异（P＞0.05），而 One Files（72s）和 One Files Blue（414s）的断裂时间最短和最长（P＜0.05）。在 Reciproc（310°）、One Files（285°）和 Reverso Silver（318°）器械中观察到相似的旋转角度（P＞0.05），明显低于 Reciproc Blue（492°）、One Files Blue（456°）和 WaveOne Gold（492°；P＜0.05）。最大弯曲负载表明 Reciproc Blue（201.3 gf）比其他器械更灵活（P＜0.05）。
尽管金属成分和未预备根管表面百分比存在相似性，但这些器械在整体几何设计、相变温度以及四个机械阻力参数（断裂时间、最大扭矩、旋转角度和最大弯曲负载）方面存在差异。
