Department of Endodontics, Future University, Cairo, Egypt.
J Endod. 2012 Jul;38(7):996-1000. doi: 10.1016/j.joen.2012.03.018. Epub 2012 May 11.
A great number of nickel-titanium (NiTi) rotary systems with noncutting tips, different cross-sections, superior resistance to torsional fracture, varying tapers, and manufacturing method have been introduced to the market. The purpose of this study was to evaluate and compare the effect of 4 rotary NiTi preparation systems, Revo-S (RS; Micro-Mega, Besancon Cedex, France), Twisted file (TF; SybronEndo, Amersfoort, The Netherlands), ProFile GT Series X (GTX; Dentsply, Tulsa Dental Specialties, Tulsa, OK), and ProTaper (PT; Dentsply Maillefer, Ballaigues, Switzerland), on volumetric changes and transportation of curved root canals.
Forty mesiobuccal canals of mandibular molars with an angle of curvature ranging from 25° to 40° were divided according to the instrument used in canal preparation into 4 groups of 10 samples each: group RS, group TF, group GTX, and group PT. Canals were scanned using an i-CAT CBCT scanner (Imaging Science International, Hatfield, PA) before and after preparation to evaluate the volumetric changes. Root canal transportation and centering ratio were evaluated at 1.3, 2.6, 5.2, and 7.8 mm from the apex. The significance level was set at P ≤ .05.
The PT system removed a significantly higher amount of dentin than the other systems (P = .025). At the 1.3-mm level, there was no significant difference in canal transportation and centering ratio among the groups. However, at the other levels, TF maintained the original canal curvature recording significantly the least degree of canal transportation as well as the highest mean centering ratio.
The TF system showed superior shaping ability in curved canals. Revo-S and GTX were better than ProTaper regarding both canal transportation and centering ability.
市场上推出了大量带有非切割尖端、不同横截面、抗扭转断裂性能更高、锥度不同以及制造方法各异的镍钛（NiTi）旋转系统。本研究旨在评估和比较 4 种旋转镍钛预备系统，即 Revo-S（RS；Micro-Mega，Besancon Cedex，法国）、Twisted file（TF；SybronEndo，Amersfoort，荷兰）、ProFile GT Series X（GTX；Dentsply，Tulsa Dental Specialties，Tulsa，OK）和 ProTaper（PT；Dentsply Maillefer，Ballaigues，瑞士）对弯曲根管的体积变化和偏移的影响。
根据根管预备中使用的器械，将 40 个下颌磨牙近颊根管分为 4 组，每组 10 个样本：RS 组、TF 组、GTX 组和 PT 组。预备前后使用 i-CAT CBCT 扫描仪（Imaging Science International，Hatfield，PA）对根管进行扫描，以评估体积变化。在距根尖 1.3、2.6、5.2 和 7.8 mm 处评估根管偏移和中心定位比。显著性水平设为 P≤0.05。
PT 系统去除的牙本质量明显高于其他系统（P=0.025）。在 1.3 mm 水平，各组间根管偏移和中心定位比无显著差异。然而，在其他水平，TF 保持原始根管曲率的记录最小程度的根管偏移和最高的平均中心定位比。
TF 系统在弯曲根管中具有优越的成形能力。Revo-S 和 GTX 在根管偏移和中心定位能力方面优于 ProTaper。
