Division of Endodontology, Department of Preventive Dentistry, Periodontology, and Cariology, University of Zürich Center for Dental Medicine, Zürich, Switzerland.
Int Endod J. 2011 Feb;44(2):148-53. doi: 10.1111/j.1365-2591.2010.01823.x. Epub 2010 Nov 17.
To investigate the impact of sequential irrigation procedures on accumulated hard tissue debris (AHTD) levels in canal systems in mesial roots of human mandibular molars after instrumentation.
Based on pre-scans in a micro-computed tomography (μCT) system, 20 extracted human mandibular molars with joining mesial root canals and an isthmus between these were selected. Canals were instrumented using the ProTaper rotary system until the F3 instrument reached working length. A 1% NaOCl solution was applied during instrumentation, followed by a final 5-mL flush to working length. Subsequently, canals were irrigated with 5 mL of 17% EDTA. Thereafter, passive ultrasonic irrigation (PUI) was performed using 1% NaOCl on three occasions each for 20 s. Percent values of total canal system volume filled with AHTD were calculated based on high-resolution scans after each irrigation step. Data was compared using repeated measure anova followed by paired t-test for individual comparisons. Bonferroni's correction was applied for multiple testing; the alpha-type error was set at 1%.
Instrumentation of the root canals in conjunction with 1% NaOCl irrigation left 6.9 ± 4.2 vol.% of the total canal system volume filled with AHTD. This value was significantly (P < 0.01) reduced to 4.9 ± 3.6 vol.% after EDTA irrigation. Subsequent PUI resulted in a further significant (P < 0.01) reduction to 3.7 ± 2.8 vol.%.
In this quantitative study on AHTD reduction, a significant effect of EDTA and PUI was shown. However, approximately half of the debris that accumulated during instrumentation remained in the canal system.
研究在器械预备后，顺次冲洗程序对下颌磨牙近中根管系统中累积的硬性组织碎屑（AHTD）水平的影响。
基于微计算机断层扫描（μCT）系统的预扫描，选择了 20 颗具有连接近中根管和这些根管之间的峡部的下颌磨牙。使用 ProTaper 旋转系统对根管进行器械预备，直至 F3 器械达到工作长度。在器械预备过程中使用 1% NaOCl 溶液，随后用最后 5 毫升冲洗至工作长度。随后，用 5 毫升 17% EDTA 冲洗根管。之后，使用 1% NaOCl 对 PUI 进行三次各 20 秒的处理。根据每次冲洗步骤后的高分辨率扫描计算总根管系统体积中填充的 AHTD 的百分比值。使用重复测量方差分析比较数据，然后进行个体比较的配对 t 检验。对于多次测试应用 Bonferroni 校正；α型错误设置为 1%。
根管的器械预备与 1% NaOCl 冲洗相结合，使总根管系统体积的 6.9 ± 4.2%充满了 AHTD。这一数值在用 EDTA 冲洗后显著（P < 0.01）减少至 4.9 ± 3.6%。随后的 PUI 导致进一步显著（P < 0.01）减少至 3.7 ± 2.8%。
在这项关于 AHTD 减少的定量研究中，EDTA 和 PUI 显示出显著的效果。然而，在器械预备过程中积累的碎屑中，约有一半仍留在根管系统中。
