Influence of root canal irrigants on the antimicrobial efficacy and bacterial communities of oral mixed biofilms under dynamic oxygen conditions
10.12016/j.issn.2096-1456.202660150
- Author:
SHI Baojiang
1
;
YANG Zi
2
;
SU Zheng
2
Author Information
1. Department of Operative Dentistry and Endodontics, Beijing Stomatological Hospital, Capital Medical University
2. International Medical Services and Healthcare Center, Beijing Stomatological Hospital, Capital Medical University
- Publication Type:Journal Article
- Keywords:
root canal;
microbial biofilm;
root canal irrigating solution;
anaerobic culture;
aerobic culture;
antimicrobial efficacy;
high-throughput sequencing;
bacterial communities
- From:
Journal of Prevention and Treatment for Stomatological Diseases
2026;34(9):886-894
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the bactericidal efficacy and impact on oral mixed biofilm microbial structure of commonly used clinical root canal irrigants under dynamic oxygen conditions, and to provide experimental evidence for clinical root canal irrigant selection.
Methods:This study has been reviewed and approved by the Medical Ethics Committee, and written informed consent has been obtained from all of the participants. Two healthy oral volunteers from Beijing Stomatological Hospital, Capital Medical University were selected, and subgingival and supragingival plaque from their mandibular premolars and molars were extracted to construct an oral mixed microbial biofilm model. The plaque was cultivated on hydroxyapatite slices for 1 week (anaerobic conditions for 3 days + aerobic conditions for 4 days) to construct a young oral mixed bacterial biofilm model, and cultivated for 3 weeks (anaerobic conditions for 3 days + aerobic conditions for 18 days) to construct a mature oral mixed bacterial biofilm model. Three root canal irrigating solutions were used: sterile water (control), 2% chlorhexidine (CHX), and 1% sodium hypochlorite (NaOCl). The bacterial biofilms were treated for 1 week and 3 weeks, respectively, and the overall bactericidal rate was assessed using live/dead bacterial staining and laser confocal microscopy. Concurrently, high-throughput 16S rRNA sequencing was performed to analyze the microbial community structure and to evaluate the antibacterial effects of irrigation solution, on common dominant pathogens
Results:The proportion of dead bacteria in the biofilm treated with three types of root canal irrigation drugs at 1 week and 3 weeks, from high to low, were as follows: 1% NaOCl >2% CHX >control group (P < 0.001). The bactericidal rate of 1% NaOCl on mature biofilms at 3 weeks was significantly lower than that of light biofilms at 1 year (P < 0.001). High-throughput sequencing revealed minimal effects of 2% CHX and 1% NaOCl on biofilm community structure but demonstrated poor bactericidal activity against dominant root canal pathogens, such as Streptococcus and Fusobacterium.
Conclusion:Under the initial anaerobic and subsequent aerobic culture conditions, 1% NaOCl exhibits potent bactericidal effects on young bacterial biofilms, but demonstrates limited efficacy against mature biofilms and certain root canal dominant bacteria (Streptococcus and Fusobacterium).
- Full text:2026091115244416893根管冲洗药物对动态氧条件下口腔混合菌群生物膜的杀菌效果及菌群结构的影响.pdf
