Krajczár Károly, Varga Enikő, Marada Gyula, Jeges Sára, Tóth Vilmos
DMD. Clinical Consultant. Dental School, Faculty of Medicine, University of Pécs, Hungary.
DMD. Private practice, Budapest, Hungary.
J Clin Exp Dent. 2016 Apr 1;8(2):e136-40. doi: 10.4317/jced.52561. eCollection 2016 Apr.
The purpose of this study was to investigate the consistency of working length control between hand instrumentation in comparison to engine driven Mtwo nickel-titanium rotary files.
Forty extracted maxillary molars were selected and divided onto two parallel groups. The working lengths of the mesiobuccal root canals were estimated. The teeth were fixed in a phantom head. The root canal preparation was carried out group 1 (n=20) with hand K-files, (VDW, Munich, Germany) and group 2 (n=20) with Mtwo instruments (VDW, Munich, Germany). Vestibulo-oral and mesio-distal directional x-ray images were taken before the preparation with #10 K-file, inserted into the mesiobuccal root canal to the working length, and after preparation with #25, #30 and #40 files. Working lenght changes were detected with measurements between the radiological apex and the instrument tips.
In the Mtwo group a difference in the working competency (p<0.05) could be noticed only in the vestibulo-oral direction from #10 to #40 file. The hand instrument group showed a significant difference in working length competency for each larger file size (p<0.05) (ANOVA). Regression analysis in the hand instrumentation group indicated a working length decrease with a mean of 0,2 mm after each consecutive file size (p<0.01).
The outcome of our trial indicated a high consistency in working length control for root canal preparation under simulated clinical condition using Mtwo rotary files. Mtwo NiTi rotary file did therefore proved to be more accurate in comparison to the conventional hand instrumentation.
Working length, Mtwo, nickel-titanium, hand preparation, engine driven preparation.
本研究旨在调查与机用Mtwo镍钛旋转锉相比，手动器械在工作长度控制方面的一致性。
选取40颗拔除的上颌磨牙并分为两个平行组。估计近中颊根管的工作长度。将牙齿固定在仿头模中。第1组（n = 20）使用手动K锉（德国慕尼黑VDW公司）进行根管预备，第2组（n = 20）使用Mtwo器械（德国慕尼黑VDW公司）进行根管预备。在使用#10 K锉插入近中颊根管至工作长度进行预备前，以及使用#25、#30和#40锉预备后，拍摄前庭-口腔和近中-远中方向的X线图像。通过测量放射学根尖与器械尖端之间的距离来检测工作长度的变化。
在Mtwo组中，仅在从#10到#40锉的前庭-口腔方向上可注意到工作能力的差异（p < 0.05）。手动器械组在每个更大的锉尺寸下工作长度能力均显示出显著差异（p < 0.05）（方差分析）。手动器械组的回归分析表明，每连续增大一个锉尺寸后工作长度平均减少0.2 mm（p < 0.01）。
我们试验的结果表明，在模拟临床条件下使用Mtwo旋转锉进行根管预备时，工作长度控制具有高度一致性。因此，与传统手动器械相比，Mtwo镍钛旋转锉被证明更准确。
工作长度；Mtwo；镍钛；手动预备；机用预备
