Grando Caroline Pietroski, Martinez Elizabeth Ferreira, Fontana Carlos Eduardo, Pedro Rocha Daniel Guimarães, Pessoa Stringheta Carolina, da Silveira Bueno Carlos Eduardo
Department of Endodontics, São Leopoldo Mandic Dental Research Center, Campinas, SP, Brazil.
Department of Endodontics, Pontifícia Universidade Católica de Campinas, Campinas, SP, Brazil.
Iran Endod J. 2019 Winter;14(1):56-62. doi: 10.22037/iej.v14i1.22190.
The aim of this study was to evaluate the effectiveness of 2.5% sodium hypochlorite associated with 17% Ethylenediaminetetraacetic acid (NaOCl-EDTA), that of 1% peracetic acid (PA), in removing the smear layer, as assessed by scanning electron microscopy (SEM), and in exerting bactericidal action against ( as assessed by the real-time polymerase chain reaction (real-time PCR).
Fifty-five extracted mandibular single-rooted premolars were selected, and divided into two experimental groups (NaOCl-EDTA and PA; =25) and one control group (0.9% saline; =5). Pre- and post-instrumentation samples were collected and assessed for the presence of using real-time PCR. The teeth were instrumented using hand files and the ProTaper Universal system (hybrid technique) for a standardized time of 7 min. A total of 20 mL of NaOCl followed by 5 mL of EDTA were applied during instrumentation in the NaOCl-EDTA group, whereas 20 mL of PA and 20 mL of saline were applied in the PA and control groups, respectively. An additional 5 mL of saline was applied in all the groups to neutralize the environment. A scoring system was used to conduct the SEM assessment. The results were submitted to the Kruskal-Wallis test, complemented by Dunn's test (SEM analysis) (<0.05).
A significant microbial reduction was observed in both the PA and the NaOCl-EDTA groups (<0.05). In the PA group, the presence of a smear layer in the apical third was significantly greater than in the cervical third (<0.05); no significant differences were observed between the middle and cervical thirds, or between the middle and apical thirds (>0.05). In the NaOCl-EDTA group, the smear layer scores were significantly higher in the apical third than in the cervical and middle thirds (<0.05).
This study showed that there was no significant difference between PA and NaOCl-EDTA irrigation regimens regarding either antimicrobial action against or removal of the smear layer, except for greater removal in the middle third by the NaOCl-EDTA group.
本研究旨在通过扫描电子显微镜（SEM）评估2.5%次氯酸钠与17%乙二胺四乙酸（NaOCl-EDTA）、1%过氧乙酸（PA）去除玷污层的效果，并通过实时聚合酶链反应（实时PCR）评估其对[具体细菌名称未给出]的杀菌作用。
选取55颗拔除的下颌单根前磨牙，分为两个实验组（NaOCl-EDTA组和PA组；每组25颗）和一个对照组（0.9%生理盐水组；5颗）。在器械操作前后采集样本，使用实时PCR检测[具体细菌名称未给出]的存在情况。使用手用锉和ProTaper Universal系统（混合技术）对牙齿进行器械操作，标准化时间为7分钟。在NaOCl-EDTA组器械操作过程中，共应用20 mL NaOCl，随后应用5 mL EDTA，而在PA组和对照组分别应用20 mL PA和20 mL生理盐水。所有组均额外应用5 mL生理盐水以中和环境。使用评分系统进行SEM评估。结果采用Kruskal-Wallis检验，并辅以Dunn检验（SEM分析）（P<0.05）。
PA组和NaOCl-EDTA组均观察到显著的微生物减少（P<0.05）。在PA组中，根尖三分之一处玷污层的存在显著多于颈三分之一处（P<0.05）；在中三分之一与颈三分之一之间，以及中三分之一与根尖三分之一之间未观察到显著差异（P>0.05）。在NaOCl-EDTA组中，根尖三分之一处的玷污层评分显著高于颈三分之一和中三分之一处（P<0.05）。
本研究表明，PA和NaOCl-EDTA冲洗方案在对[具体细菌名称未给出]的抗菌作用或玷污层去除方面没有显著差异，除了NaOCl-EDTA组在中三分之一处的去除效果更好。
