Abstract：
This study aims to compare the shaping ability of three systems using micro-computed tomography (micro-CT). Moderately-curved mesial canals of 36 mandibular molars were assigned to three groups (n = 24); Protaper Next (PTN, 0.25, 0.06), WaveOne Gold (WOG, 0.25, 0.07), TruNatomy (TRN, 0.25, 0.04), and instrumentation was performed. Pre- and post-micro-CT scans were obtained. Canal volume and surface, structure model index (SMI), centroid shift, canal transportation, and untouched canal were analyzed. One-way ANOVA and Student\'s t-test were used for statistics. There was no difference in SMI, centroid shift, and centering ability between the study groups (p > .05). Removed dentin and canal surface changes were lower in TRN, while untouched dentin walls were higher (p < .05). Cross-sections became more rounded (p < .05), but not significant between groups (p > .05). Considering the removed dentin by TRN, it can be used in critical dentin thickness, such as the danger zone (DZ). PTN, WOG, and WOG kept the original canal course similarly. Untouched dentin by TRN (41%) was wider than PTN and WOG, consequently, meticulous irrigation is recommended. TRN, which provides a controlled increase in canal volume, can be used in thin dentin such as the DZ, however, its use should be supported by copious irrigation and brushing considering the rate of untouched dentin walls. RESEARCH HIGHLIGHTS: TRN presented a higher untouched dentin wall compared to PTN and WOG. Canal volume and surface changes were the lowest in the TRN group. The centering abilities were similar in PTN, WOG, and TRN.
摘要：
本研究旨在比较使用微型计算机断层扫描（micro-CT）的三种系统的成形能力。36个下颌磨牙的中度弯曲的近中管被分配到三组（n=24）；ProtaperNext（PTN，0.25,0.06),WaveOneGold(WOG,0.25,0.07),TruNatomy(TRN,0.25,0.04),并进行了仪器操作。获得前和后微CT扫描。运河体积和表面，结构模型指数(SMI)，质心偏移,运河运输,并对未触及的运河进行了分析。采用单因素方差分析和学生t检验进行统计。SMI没有区别，质心偏移,和研究组之间的中心能力（p>0.05）。在TRN中，去除的牙本质和根管表面变化较低，而未触及的牙本质壁较高（p<0.05）。横截面变得更圆（p<0.05），但组间不显著(p>.05)。考虑到TRN去除的牙本质，它可以用于临界牙本质厚度，例如危险区域(DZ)。PTN,WOG,和WOG保持原来的运河路线类似。TRN未触及的牙本质（41％）比PTN和WOG宽，因此,建议精心灌溉。TRN,这提供了运河容积的受控增加，可用于薄牙本质，如DZ，然而,考虑到未触及的牙本质壁的比率，应通过大量的灌溉和刷牙来支持其使用。研究重点：与PTN和WOG相比，TRN表现出更高的未触及牙本质壁。TRN组的运河体积和表面变化最低。PTN的居中能力相似，WOG,和TRN。
