Abu-Tahun Ibrahim H, Kwak Sang Won, Ha Jung-Hong, Sigurdsson Asgeir, Kayahan Mehmet Baybora, Kim Hyeon-Cheol
Department of Conservative Dentistry, School of Dentistry, The University of Jordan, Amman 11942, Jordan.
Department of Conservative Dentistry, School of Dentistry, Pusan National University, Dental Research Institute, Yangsan 50612, Korea.
Materials (Basel). 2019 Feb 5;12(3):493. doi: 10.3390/ma12030493.
This study compared the torque generation during canal shaping with a nickel-titanium endodontic instrument according to the extent of glide-path establishment. Seventy-five simulated S-shaped canal blocks were divided into five groups (n = 15) according to the number of repetitive insertions to the working length using a One G glide-path instrument: groups with 5, 10, 15, and 20 insertions as well as group Z without glide-path establishment. When the tip of the One G file reached the working length, the file was moved back and forth repetitively at the working length for the designated number of times for each group. The instrumentation procedure with HyFlex EDM had 15 pecking strokes. During instrumentation, the generated torque was transmitted to a customized data acquisition module and collected using customized software. Data were computed to determine the maximum torque and total stress. The maximum screw-in forces were statistically analyzed using one-way analysis of variance and Tukey's post hoc comparison test with a significance level of 95%. While the maximum stress did not have significant differences among the five groups ( > 0.05), groups with more than 10 repetitive insertions generated lower total stress during instrumentation than did the group with 5 insertions and group Z ( < 0.05). Under the limitations of this study, repetitive insertions of glide-path establishment files at the working length reduced stress generation during the shaping using nickel-titanium instruments.
本研究根据滑行通道建立的程度，比较了使用镍钛根管器械进行根管预备时的扭矩产生情况。将75个模拟S形根管块根据使用One G滑行通道器械向工作长度重复插入的次数分为五组（n = 15）：分别为插入5次、10次、15次和20次的组，以及未建立滑行通道的Z组。当One G锉的尖端到达工作长度时，将锉在工作长度上来回重复移动指定的次数。使用HyFlex EDM进行预备操作时有15次啄击行程。在预备过程中，产生的扭矩被传输到定制的数据采集模块，并使用定制软件进行收集。计算数据以确定最大扭矩和总应力。使用单因素方差分析和Tukey事后比较检验对最大旋入力进行统计学分析，显著性水平为95%。虽然五组之间的最大应力没有显著差异（> 0.05），但重复插入次数超过10次的组在预备过程中产生的总应力低于插入5次的组和Z组（< 0.05）。在本研究的局限性下，在工作长度上重复插入滑行通道建立锉可减少使用镍钛器械进行预备时的应力产生。
