Aggarwal Arunima, Nawal Ruchika Roongta, Yadav Seema, Talwar Sangeeta, Kunnoth Sriram, Mahajan Puneet
Department of Conservative Dentistry and Endodontics, Maulana Azad Institute of Dental Sciences, New Delhi, India.
Department of Conservative Dentistry and Endodontics, Maulana Azad Institute of Dental Sciences, New Delhi, India.
J Endod. 2021 Aug;47(8):1314-1320. doi: 10.1016/j.joen.2021.05.004. Epub 2021 May 21.
This study aimed to compare root dentinal microcrack formation after root canal shaping using rotary, reciprocating, and adaptive instruments at different working lengths using micro-computed tomographic imaging.
One hundred eighty extracted mature mandibular molar mesial roots with 2 separate canals were selected. The mesial roots were resected at the cementoenamel junction and randomly divided into 4 groups (n = 45) based on the nickel-titanium file system used: ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Gold (Dentsply Maillefer), Twisted File Adaptive (SybronEndo, Orange, CA), and Reciproc Blue (VDW, Munich, Germany). Each of the 4 groups were then subdivided into 3 groups (n = 15) depending on the working length used for root canal preparation (ie, instrumentation 1 mm short, flush, and 1 mm beyond the major apical foramen). The roots were imaged with micro-computed tomographic scanning before and after root canal preparation. The cross-sectional images generated were screened to detect the presence of new microcracks.
The ProTaper Universal system significantly increased the number of postinstrumentation microcracks at all working lengths (P ≤ .05). No significant increase (P > .05) in postinstrumentation microcracks was observed in the ProTaper Gold, Twisted File Adaptive, or Reciproc Blue groups.
Rotary instrumentation induced a higher number of dentinal microcracks compared with reciprocating and adaptive instruments. Instrumentation at different working lengths did not significantly influence the formation of dentinal microcracks.
本研究旨在使用显微计算机断层扫描成像技术，比较在不同工作长度下，使用旋转、往复和自适应器械进行根管预备后牙根牙本质微裂纹的形成情况。
选取180颗拔除的成熟下颌磨牙近中根，每颗牙根有2个独立根管。在牙骨质釉质界处切除近中根，并根据所使用的镍钛锉系统随机分为4组（n = 45）：ProTaper Universal（登士柏迈徕特，瑞士拜莱格）、ProTaper Gold（登士柏迈徕特）、Twisted File Adaptive（赛柏蓝，加利福尼亚州奥兰治）和Reciproc Blue（VDW，德国慕尼黑）。然后，根据根管预备所使用的工作长度，将这4组中的每组再细分为3组（n = 15）（即器械操作比主要根尖孔短1 mm、平齐、超出主要根尖孔1 mm）。在根管预备前后，对牙根进行显微计算机断层扫描成像。对生成的横断面图像进行筛查，以检测新微裂纹的存在。
ProTaper Universal系统在所有工作长度下均显著增加了器械操作后微裂纹的数量（P≤0.05）。在ProTaper Gold、Twisted File Adaptive或Reciproc Blue组中，未观察到器械操作后微裂纹有显著增加（P>0.05）。
与往复式和自适应器械相比，旋转器械操作导致更多的牙本质微裂纹。在不同工作长度下进行器械操作对牙本质微裂纹的形成没有显著影响。
