Department of Endodontics, Faculty of Dentistry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey.
Clin Oral Investig. 2021 Mar;25(3):1077-1084. doi: 10.1007/s00784-020-03404-3. Epub 2020 Jun 19.
The separated root canal instruments may affect the quality of root canal filling, hence the success of endodontic treatment. The aim of this study was to evaluate the effects of separated file fragments of nickel-titanium rotary systems with different cross-section, taper and motion characteristics on the apical sealer penetration in oval-shaped root canals via confocal laser scanning microscope (CLSM).
Distal roots of 60 mandibular molars with oval-shaped root canals were randomly divided into 4 groups as follows: group 1, FlexMaster Nickel Titanium Rotary File System (NTRFS) (separated instrument: 30/.06); group 2, ProTaper Next NTRFS (X3); group 3, ProTaper Universal NTRFS (F3); group 4, Revo-S NTRFS (AS30/.06). Root canals were filled with gutta-percha and AH plus labelled with 0.1% rhodamine B using a warm vertical compaction technique. Each specimen was horizontally sectioned at 1st, 3rd and 5th mm from apical foramen. Amount of maximum and average penetration depths, penetration percentage and sealer penetrated area were measured and analysed with one-way repeated measures of ANOVA and the Bonferroni post hoc tests. p < 0.05 was considered significant.
The penetration depth, percentage and penetrated area of the sealer increased from apical to coronal in all systems. The maximum and average penetration depths and penetration areas were higher in FlexMaster and Revo-S groups at the 3rd mm (p < 0.05). At the 5th mm, the Revo-S group had a higher penetration percentage, when compared with ProTaper Next and ProTaper Universal groups (p < 0.05).
In the 1st mm, separated fragments of any system did not allow the penetration of the sealer, while it was observed that the files with constant taper showed more positive results in terms of sealer penetration at apical 3rd and 5th mm.
In the presence of a separated file, the taper of the file might significantly affect the amount of penetrated sealer into the dentinal tubules as compared with the cross-section and motion characteristics of the file.
分离的根管器械可能会影响根管充填质量，从而影响根管治疗的效果。本研究的目的是通过共聚焦激光扫描显微镜（CLSM）评估不同横截面、锥度和运动特性的镍钛旋转器械分离片段对椭圆形根管根尖封闭剂渗透性的影响。
将 60 颗下颌磨牙的远中根随机分为 4 组：组 1，FlexMaster 镍钛旋转锉系统（NTRFS）（分离器械：30/.06）；组 2，ProTaper Next NTRFS（X3）；组 3，ProTaper Universal NTRFS（F3）；组 4，Revo-S NTRFS（AS30/.06）。根管采用热垂直加压技术用牙胶和 AH 加标记 0.1%罗丹明 B。每个样本在距根尖孔 1、3 和 5mm 处水平切片。用单向重复测量方差分析和 Bonferroni 事后检验测量和分析最大和平均渗透深度、渗透百分比和密封剂渗透面积。p<0.05 被认为具有统计学意义。
所有系统中，从根尖到冠方，渗透深度、百分比和渗透面积均增加。在 FlexMaster 和 Revo-S 组中，在第 3mm 时最大和平均渗透深度和渗透面积更高（p<0.05）。在第 5mm 时，Revo-S 组的渗透百分比高于 ProTaper Next 和 ProTaper Universal 组（p<0.05）。
在第 1mm 时，任何系统的分离片段都不允许密封剂渗透，而在根尖第 3 和第 5mm 处，具有恒定锥度的锉刀在密封剂渗透方面显示出更积极的结果。
在存在分离锉的情况下，与锉的横截面和运动特性相比，锉的锥度可能会显著影响进入牙本质小管的渗透密封剂的量。
