Kesim Bertan, Tezcan Ülger Seda, Aslan Gönül, Üstün Yakup, Avcı Ayşe Tuğba, Küçük Mustafa Öner
Department of Endodontics, Faculty of Dentistry, Nuh Naci Yazgan University, Kayseri 38170, Turkey.
Department of Medical Microbiology, Faculty of Medicine, Mersin University, Mersin 33343, Turkey.
Life (Basel). 2024 Dec 21;14(12):1696. doi: 10.3390/life14121696.
Effective management of primary apical periodontitis depends on understanding the dynamic interactions within the root canal microbiome. This study aimed to investigate the effect of sequential antimicrobial phases on the root canal microbiome during a two-visit treatment approach, with a focus on calcium hydroxide medication.
Samples were collected from three teeth across four treatment phases: initial infection (S1), after chemomechanical preparation (S2), after intracanal medication (S3), and after a final flush (S4). DNA was extracted, and the V3-V4 regions of the 16S rRNA gene were sequenced using Illumina MiSeq. Sequencing data were analyzed with QIIME 2, and differentially abundant taxa were identified using linear discriminant analysis effect size (LEfSe).
While microbial community composition did not differ significantly between phases, the / ratio decreased after the antimicrobial stages. LEfSe analysis revealed higher abundances of , , and in the untreated (CMP) group. was relatively more abundant in the intracanal medication (ICM) phase, and was more abundant in the final-flush (FF) phase.
Although calcium hydroxide treatment did not induce statistically significant changes in overall root canal microbial composition, trends such as a reduction in the / ratio and a relative increase in numbers suggest potential ecological shifts. The observed relative increase in numbers may represent a hypothesis-driven observation reflecting indirect ecological effects rather than direct pH modulation. While visual patterns (e.g., PCA clustering) were observed, they lacked statistical support. Further studies with larger sample sizes are needed to validate these observations and assess the potential role of beneficial bacteria in root canal treatments.
原发性根尖周炎的有效管理取决于对根管微生物群内动态相互作用的理解。本研究旨在探讨在两阶段治疗方法中，序贯抗菌阶段对根管微生物群的影响，重点关注氢氧化钙药物治疗。
在四个治疗阶段从三颗牙齿采集样本：初始感染阶段（S1）、化学机械预备后（S2）、根管内用药后（S3）和最终冲洗后（S4）。提取DNA，并使用Illumina MiSeq对16S rRNA基因的V3-V4区域进行测序。使用QIIME 2分析测序数据，并使用线性判别分析效应大小（LEfSe）识别差异丰富的分类群。
虽然各阶段之间的微生物群落组成没有显著差异，但抗菌阶段后/比值降低。LEfSe分析显示，未治疗（CMP）组中、和的丰度较高。在根管内用药（ICM）阶段相对更丰富，在最终冲洗（FF）阶段更丰富。
尽管氢氧化钙治疗未引起根管总体微生物组成的统计学显著变化，但/比值降低和数量相对增加等趋势表明可能存在生态变化。观察到的数量相对增加可能代表一种假设驱动的观察结果，反映了间接生态效应而非直接pH调节。虽然观察到了视觉模式（如主成分分析聚类），但缺乏统计学支持。需要进一步进行更大样本量的研究来验证这些观察结果，并评估有益细菌在根管治疗中的潜在作用。
