Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy.
J Endod. 2023 Oct;49(10):1344-1351. doi: 10.1016/j.joen.2023.07.019. Epub 2023 Jul 28.
This laboratory study aimed to evaluate the accumulated hard tissue debris (AHTD) and shaping performance following root canal instrumentation with a novel stainless steel rotary system (Gentlefile; MedicNRG, Kibbutz Afikim, Israel) compared with two single-file nickel-titanium instruments of different kinematics through micro-computed tomography (micro-CT) analysis.
Thirty isthmus-containing mesial roots of human mandibular molars with a curvature of 15°-35° were scanned with micro-CT at an isotropic resolution of 12 μm and randomly assigned to three groups (n = 10) according to the instruments used for canal preparation: Gentlefile (GF; #23/.04), One Curve (OC; #25/.06; Micro-Mega, Besancon, France), and Reciproc Blue R25 (RB; #25/.08; VDW, Munich, Germany). The AHTD, unprepared canal surface area, volume changes, surface area changes, and transportation were evaluated by comparing preoperative and postoperative micro-CT images. In addition, the time required for canal preparation was recorded. Data were statistically analyzed using the one-way analysis of variance (ANOVA) test or the Kruskal-Wallis test at a significance level of 5%.
No significant differences were observed in the percentage of AHTD or in the unprepared canal surface area between the three groups (P > .05). The RB group demonstrated a significantly greater percentage increase in volume and surface area than the GF group (P < .05). The GF and OC groups showed significantly less transportation at 3 mm from the apex than the RB group (P < .001). The OC group required significantly less time for instrumentation than the RB and GF groups (P < .05).
Instrumentation with GF (#23/.04), OC, and RB yielded similar levels of AHTD and unprepared surface area in isthmus-containing curved canals. GF achieved this with less dentin removal and apical transportation, at the expense of a longer preparation time.
本实验室研究旨在通过微计算机断层扫描（micro-CT）分析，评估新型不锈钢旋转系统（Gentlefile；MedicNRG，以色列 Afikim 基布兹）与两种不同运动学单文件镍钛器械根管预备后的累积硬组织碎屑（AHTD）和成形性能。
对 30 颗具有 15°-35°弯曲度的下颌磨牙近中颊根峡部进行 micro-CT 扫描，各向同性分辨率为 12μm，根据使用的器械随机分为 3 组（n=10）进行根管预备：Gentlefile（GF；#23/.04）、One Curve（OC；#25/.06；Micro-Mega，Besancon，法国）和 Reciproc Blue R25（RB；#25/.08；VDW，慕尼黑，德国）。通过比较术前和术后 micro-CT 图像，评估 AHTD、未预备根管表面积、体积变化、表面积变化和运输情况。此外，还记录了根管预备所需的时间。使用单向方差分析（ANOVA）检验或 Kruskal-Wallis 检验在 5%的显著水平下对数据进行统计学分析。
三组间 AHTD 百分比或未预备根管表面积无显著差异（P>.05）。与 GF 组相比，RB 组的体积和表面积增加百分比显著更大（P<.05）。距根尖 3mm 处，GF 和 OC 组的运输量明显小于 RB 组（P<.001）。与 RB 和 GF 组相比，OC 组的器械操作时间明显更短（P<.05）。
在含有峡部的弯曲根管中，GF（#23/.04）、OC 和 RB 的器械操作产生的 AHTD 和未预备表面面积相似。GF 以较少的牙本质去除和根尖运输为代价，达到了这一效果，但其预备时间较长。
