Keskin Cangül, Pirimoğlu Burcu, Çiftçioğlu Elif, Dinger Esma, Kömeç Onur, Keleş Ali
Department of Endodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey.
Department of Endodontics, Faculty of Dentistry, Okan University, Istanbul, Turkey.
Clin Oral Investig. 2023 Dec;27(12):7337-7344. doi: 10.1007/s00784-023-05324-4. Epub 2023 Oct 20.
This study assessed the outcome of shaping the mesial roots of mandibular first molars containing band-shaped isthmuses with an isthmus floor located at the apical third with Reciproc Blue and Rotate instruments in terms of canal transportation, canal aberrations and unprepared apical canals.
Pair-matched mesial roots of mandibular first molars according to their isthmus location (distance from apical foramina) and size were constructed based on quantitative measurements (length, major and minor diameter at isthmus roof and floor) on preoperative micro-CT scanning (n = 10). The pair-matched specimens were prepared either using Reciproc Blue R25 (25.08v) or Rotate (15.04, 20.05, 25.06) instruments and then subjected to a second micro-CT scanning. Micro-CT scans were analysed to evaluate the canal transportation at the apical foramen and isthmus floor levels and the frequency of procedural errors (separated instruments, artificial canal preparation, cross shaping and unprepared apical canals). Canal transportation values were compared using Mann-Whitney U, and the distribution of procedural errors was compared with chi-square tests with a 5% significance threshold.
Greater transportation values were detected in the apical foramen level compared to the isthmus floor in both groups. No significant difference was detected between Rotate and Reciproc Blue groups in terms of absolute transportation values and the incidence of procedural errors (p > .05).
Preparation of mesial root canals containing a band-shaped isthmus at the apical portion with Reciproc Blue and Rotate instruments caused transportation of the original canal position at the isthmus floor and the apical foramen levels and resulted in procedural errors.
This ex vivo micro-CT study using controlled pair-matched specimens showed that presence of a band-shaped isthmus complicates canal preparation procedure irrespective of the preparation systems.
本研究评估了使用Reciproc Blue和Rotate器械对下颌第一磨牙近中根进行根管预备的效果，这些近中根含有位于根尖三分之一处的带状峡部，评估指标包括根管偏移、根管形态异常以及未预备的根尖根管情况。
根据术前微型计算机断层扫描（micro-CT）（n = 10）的定量测量结果（长度、峡部顶部和底部的长径和短径），构建下颌第一磨牙近中根对，这些近中根对根据峡部位置（距根尖孔的距离）和大小进行配对。配对的标本分别使用Reciproc Blue R25（25.08v）或Rotate（15.04、20.05、25.06）器械进行预备，然后进行第二次微型计算机断层扫描。对微型计算机断层扫描图像进行分析，以评估根尖孔和峡部底部水平的根管偏移情况以及操作失误的频率（器械分离、人为根管预备、交叉预备和未预备的根尖根管）。使用Mann-Whitney U检验比较根管偏移值，并使用显著性阈值为5%的卡方检验比较操作失误的分布情况。
两组中，根尖孔水平的根管偏移值均高于峡部底部。在绝对根管偏移值和操作失误发生率方面，Rotate组和Reciproc Blue组之间未检测到显著差异（p > 0.05）。
使用Reciproc Blue和Rotate器械对根尖部含有带状峡部的下颌第一磨牙近中根管进行预备时，会导致峡部底部和根尖孔水平的原始根管位置发生偏移，并导致操作失误。
这项使用对照配对标本的体外微型计算机断层扫描研究表明，无论使用何种预备系统，带状峡部的存在都会使根管预备过程变得复杂。
