Zanesco Caroline, Só Marcus Vinicius Reis, Schmidt Sabrina, Fontanella Vania Regina Camargo, Grazziotin-Soares Renata, Barletta Fernando Branco
Department of Restorative Dentistry, Universidade Luterana do Brasil, Canoas, Rio Grande do Sul, Brazil.
Department of Conservative Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
J Endod. 2017 Mar;43(3):486-490. doi: 10.1016/j.joen.2016.11.006.
This study aimed to evaluate apical transportation (AT), centering ratio (CR), and volume increase (VI) produced after instrumentation of mesiobuccal canals of maxillary molars with hand files, rotary, and reciprocating instruments using micro-computed tomographic (micro-CT) imaging and to demonstrate the ability of digital subtraction radiography (DSR) to evaluate AT.
Forty-five canals were randomly assigned to either group K, manual K-files; PTN, ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland); or Rec, Reciproc (n = 15 for each group) for preparation. Master apical files were #25, X2 (#25/06), and R25 (#25/08), respectively. Micro-CT imaging was used to measure AT (mm) and CR (mm) at 3 different locations (1, 4, and 7 mm from the apex). VI (mm) was measured for each root third and for the whole canal. DSR (mesiodistal and buccolingual projections) was used to measure AT at 1 mm from the apex.
AT and CR values were statistically similar across the groups at 1, 4, and 7 mm. AT results obtained for the different locations were similar within each group; CR, in turn, showed statistically lower values at 1 mm. VI was statistically similar in all groups. Both DSR and micro-CT imaging showed that AT always occurred on the outside of canal curvature. The highest mean value obtained for AT was 0.215 mm.
AT, CR, and VI were similar for the K, PTN, and Rec groups. AT results were clinically irrelevant. DSR was as effective as micro-CT imaging in AT analysis and could be considered as an alternative method for assessing this outcome.
本研究旨在使用微型计算机断层扫描（micro-CT）成像技术评估使用手动锉、旋转器械和往复式器械对上颌磨牙近中颊根管进行预备后产生的根尖偏移（AT）、定心率（CR）和体积增加（VI），并展示数字减影放射成像（DSR）评估AT的能力。
将45个根管随机分为K组（手动K锉）、PTN组（ProTaper Next，登士柏迈尔牙科，瑞士巴拉格）或Rec组（Reciproc，每组n = 15）进行预备。主尖锉分别为#25、X2（#25/06）和R25（#25/08）。使用micro-CT成像在距根尖3个不同位置（1、4和7 mm）测量AT（mm）和CR（mm）。测量每个根段和整个根管的VI（mm）。使用DSR（近远中向和颊舌向投影）在距根尖1 mm处测量AT。
在1、4和7 mm处，各组间的AT和CR值在统计学上相似。每组内不同位置的AT结果相似；而CR在1 mm处显示出统计学上较低的值。所有组的VI在统计学上相似。DSR和micro-CT成像均显示AT总是发生在根管弯曲外侧。获得的AT最高平均值为0.215 mm。
K组、PTN组和Rec组的AT、CR和VI相似。AT结果在临床上不相关。在AT分析中，DSR与micro-CT成像一样有效，可被视为评估该结果的替代方法。
