Department of Operative Dentistry and Endodontology, University Medical Center, Giessen and Marburg, Germany.
Int Endod J. 2010 Mar;43(3):200-9. doi: 10.1111/j.1365-2591.2009.01659.x.
To assess the efficacy of removing Activ GP or GuttaFlow from canals using NiTi instruments.
Root canals in 55 extracted pre-molars were prepared to apical size 40, 0.04 taper. The teeth were imaged with micro-CT, and 30 teeth selected that had consistent apical size and taper of the shaped canals. They were randomly assigned to root filling with either the glass-ionomer-based ActivGP system (n = 15) or the polyvinylsiloxane-based GuttaFlow system (n = 15). After 2 weeks, canals were retreated stepwise with size 40-50 EndoSequence 0.04 taper instruments. Micro-CT scans (8 mum) were taken after use of each instrument to detect root filling residue in the coronal, middle and apical segment, and the retreatment time recorded. Residue, expressed as percentage of canal surface area, was compared between groups with t-tests, and within groups with repeated measures anova and Bonferroni-adjusted pairwise comparisons. Retreatment time was analysed with one-way anova.
The percentage of sealer residue-coated canal surface was consistently highest (P < 0.001) in the apical third of canals, and it did not differ significantly between the two root filling groups. Stepwise enlargement from size 40 to 50 significantly decreased the amount of sealer residue in both groups (P < 0.001). Retreatment time did not differ significantly between groups.
Both root fillings with ActivGP and GuttaFlow were removed with nickel-titanium rotary instruments. Enlargement of canals up to two sizes beyond the pre-retreatment size was necessary to minimize the amount of sealer remaining.
评估使用镍钛器械清除 Activ GP 或 GuttaFlow 从根管中的效果。
对 55 颗前磨牙进行根管预备，根尖尺寸为 40 ， 0.04 锥度。用微 CT 对牙齿进行成像，选择 30 颗具有一致的根尖尺寸和成形根管锥度的牙齿。将它们随机分配到使用玻璃离子基 ActivGP 系统（n = 15）或聚硅氧烷基 GuttaFlow 系统（n = 15）进行根管充填。2 周后，使用尺寸为 40-50 的 EndoSequence 0.04 锥度器械逐步对根管进行再处理。使用每种器械后，均进行微 CT 扫描（8 微米），以检测冠、中、根尖段根管充填残余物，并记录再处理时间。用 t 检验比较两组之间的残余物（以根管表面积的百分比表示），用重复测量方差分析和 Bonferroni 调整的两两比较比较组内差异。用单向方差分析分析再处理时间。
在根管的根尖三分之一处，密封剂残余物覆盖的根管表面百分比始终最高（P < 0.001），且在两个根管充填组之间无显著差异。从 40 号尺寸到 50 号尺寸的逐步扩大显著减少了两组中的密封剂残余物量（P < 0.001）。两组之间的再处理时间无显著差异。
Activ GP 和 GuttaFlow 两种根管充填物均可用镍钛旋转器械清除。在尽可能减少剩余密封剂的情况下，需要将根管扩大到比预处理尺寸大两个尺寸。
