Faculdade São Leopoldo Mandic, Instituto de Pesquisas São Leopoldo Mandic, Endodontia, Campinas, São Paulo, Brazil.
Department of Endodontics, City University of São Paulo, São Paulo, São Paulo, Brazil.
J Endod. 2020 Aug;46(8):1120-1124. doi: 10.1016/j.joen.2020.05.007. Epub 2020 Jun 1.
This study aimed to assess whether ultrasonic activation (UA) or the EasyClean (EC; BassiEndo, Belo Horizonte, BH, Brazil) or EDDY (ED; VDW, Munich, Germany) systems used to promote agitation of the irrigating solutions during the final irrigation step can lead to smear layer formation in the apical third of the root canal.
Thirteen premolars were instrumented with the Reciproc R40 file (VDW) and embedded in silicone, forming a closed irrigation/aspiration system. The teeth were cleaved, and 4 indentations were made on the inner buccal wall of the canal to standardize the observation sites. All the specimens were cleaned in an ultrasonic bath and evaluated under environmental scanning electron microscopy, thus constituting the control group. The same specimens were reassembled, submitted to final irrigation using UA or the ED or EC systems, and classified using a 4-level scoring system. The data were analyzed using the kappa, Pearson, and Kruskal-Wallis tests (P < .05).
Smear layer formation occurred in all of the experimental groups and at all apical levels. At 3 and 4 mm, all of the experimental groups had significantly higher levels of smear layer formation than the control group. At 2 mm, the level of smear layer formation in the UA group was significantly higher than that of the control group, and there were no significant differences among the EC, ED, and control groups. At 1 mm, there were no significant differences between the ED and control groups, and the levels of smear layer formation in the EC and UA groups were significantly higher than that of the control group. There were no significant differences between the ED and EC groups at any of the apical levels.
The smear layer formation occurred in all of the specimens submitted to final irrigation, irrespective of the technique used.
本研究旨在评估在最终冲洗步骤中使用超声激活（UA）或 EasyClean（EC；BassiEndo，贝洛奥里藏特，巴西）或 EDDY（ED；VDW，慕尼黑，德国）系统促进冲洗液搅拌是否会导致根管根尖三分之一处形成玷污层。
13 颗前磨牙用 Reciproc R40 锉（VDW）进行器械预备并嵌入硅橡胶中，形成一个封闭的冲洗/抽吸系统。牙齿被劈开，在根管内壁的颊侧内表面上制作 4 个凹陷，以标准化观察部位。所有标本均在超声浴中清洗，并在环境扫描电子显微镜下进行评估，构成对照组。相同的标本重新组装，使用 UA 或 ED 或 EC 系统进行最终冲洗，并使用 4 级评分系统进行分类。使用卡帕、皮尔逊和克鲁斯卡尔-沃利斯检验（P <.05）分析数据。
所有实验组和所有根尖水平均出现玷污层形成。在 3 和 4 mm 处，所有实验组的玷污层形成水平均显著高于对照组。在 2 mm 处，UA 组的玷污层形成水平显著高于对照组，而 EC、ED 和对照组之间无显著差异。在 1 mm 处，ED 组与对照组之间无显著差异，而 EC 和 UA 组的玷污层形成水平显著高于对照组。在任何根尖水平，ED 和 EC 组之间均无显著差异。
所有接受最终冲洗的标本均出现玷污层形成，无论使用何种技术。
