Discipline of Endodontic, Department of Dentistry, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil.
Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
Int Endod J. 2018 Jan;51 Suppl 1:e12-e22. doi: 10.1111/iej.12783. Epub 2017 May 23.
This randomized clinical trial aimed to compare the effectiveness of ultrasonic activation with that of nonactivated irrigation on the removal of bacteria and endotoxin from root canals.
Fifty patients with necrotic pulps and asymptomatic apical periodontitis were randomly allocated into two groups according to the final irrigation protocol after root canal preparation: Group UI - ultrasonic irrigation (n = 25) and Group NI - needle irrigation (n = 25). The root canals were medicated with calcium hydroxide for 14 days. Microbiological sampling was performed before (S1) and after the root canal preparation (S2), after the irrigation protocols (S3) and after the removal of the intracanal medication (S4). Total bacteria counts were determined by qPCR and the endotoxin levels by the limulus amebocyte lysate assay. Intragroup analyses were performed using the Wilcoxon test for related samples, whereas intergroup analyses were performed using the Mann-Whitney U-test (P < 0.05).
All S1 samples were positive for bacteria, with median numbers of 1.49 × 10 and 8.55 × 10 bacterial cells for the UI and NI groups, respectively. This number significantly decreased in S2 samples (UI: 1.41 × 10 ; NI: 3.53 × 10 ; both with P < 0.001). After final irrigation protocols, there was a significant decrease in bacterial load from S2 to S3 samples in both groups (UI: 4.29 × 10 ; NI: 1.08 × 10 ; P < 0.01). Intergroup analysis revealed a significant difference between irrigation methods regarding bacterial counts in S3 samples (P < 0.05). In contrast, no significant differences were observed between groups for endotoxin levels (P > 0.05).
Ultrasonic activation was more effective than nonactivated irrigation for reducing the number of bacteria but not the endotoxin levels in root canals of teeth with apical periodontitis.
本随机临床试验旨在比较超声激活与非激活冲洗在清除根管内细菌和内毒素方面的效果。
50 例患有坏死性牙髓和无症状根尖周炎的患者，根据根管预备后的最终冲洗方案，随机分为两组：超声冲洗组（UI 组，n=25）和针式冲洗组（NI 组，n=25）。根管用氢氧化钙封药 14 天。在根管预备前（S1）、根管预备后（S2）、冲洗后（S3）和根管内药物清除后（S4）进行微生物采样。通过 qPCR 测定总细菌计数，通过鲎试验测定内毒素水平。采用 Wilcoxon 相关样本检验进行组内分析，采用 Mann-Whitney U 检验进行组间分析（P<0.05）。
所有 S1 样本均为细菌阳性，UI 组和 NI 组的细菌中位数分别为 1.49×10 和 8.55×10 细菌细胞。S2 样本数量显著减少（UI：1.41×10；NI：3.53×10；均 P<0.001）。在最终冲洗方案后，两组 S3 样本的细菌负荷均从 S2 样本显著下降（UI：4.29×10；NI：1.08×10；P<0.01）。组间分析显示，两组 S3 样本的细菌计数存在显著差异（P<0.05）。然而，两组之间内毒素水平无显著差异（P>0.05）。
与非激活冲洗相比，超声激活更有效地减少根尖周炎牙齿根管内的细菌数量，但对内毒素水平无影响。
