Department of Microbiology, School of Dentistry, University of Granada, Granada, Spain.
J Endod. 2010 Jan;36(1):87-90. doi: 10.1016/j.joen.2009.10.013.
Enterococcus faecalis is the most commonly isolated bacteria from root canals of teeth with persistent periapical periodontitis. Its ability to grow as a biofilm impedes the elimination of E. faecalis by using irrigating solutions. The purpose of this study was to assess the efficacy of cetrimide and chlorhexidine (CHX), alone and in association, in combined and alternating form, in eradicating biofilms of E. faecalis.
Biofilms grown in the MBEC-high-throughput device for 24 hours were exposed to irrigating solutions for 30 seconds and 1 and 2 minutes. Eradication was defined as 100% kill of biofilm bacteria. The Student t test was used to compare the efficacy of the associations of the 2 irrigants.
Cetrimide eradicated E. faecalis biofilms at concentrations of 0.5%, 0.0312%, and 0.0078% at 30 seconds and 1 and 2 minutes of contact time, respectively. CHX did not eradicate the biofilms at any of the concentrations (4% initial concentration) or times assayed. The association of 0.1% and 0.05% cetrimide with any concentration of CHX, whether in combined or alternating application, effectively eradicated E. faecalis biofilms at all the contact times tested. Eradication was also achieved with 0.02% and 0.01% cetrimide at 2 minutes. Statistical analysis revealed significantly better results with alternating rather than combined use of cetrimide and CHX (P < .05).
The associated use of cetrimide and CHX provided better results than their applications as single agents against E. faecalis biofilms, and the alternating application was significantly more effective than the combined mode of application.
粪肠球菌是导致有持续性根尖周炎的牙髓腔中最常分离出的细菌。其形成生物膜的能力会阻碍使用冲洗液来清除粪肠球菌。本研究旨在评估单独使用西曲溴铵和洗必泰（CHX），以及联合使用这两种药物以联合和交替的形式，在消除粪肠球菌生物膜方面的效果。
在 MBEC 高通量装置中培养 24 小时的生物膜，然后用冲洗液处理 30 秒和 1 分钟、2 分钟。将消除定义为生物膜细菌 100%被杀死。使用学生 t 检验比较两种冲洗剂联合的效果。
西曲溴铵在 30 秒和 1 分钟、2 分钟接触时间时，浓度为 0.5%、0.0312%和 0.0078%时可消灭粪肠球菌生物膜。在任何浓度（初始浓度 4%）或测试时间下，CHX 都不能消灭生物膜。0.1%和 0.05%的西曲溴铵与任何浓度的 CHX 联合应用，无论是联合应用还是交替应用，在所有测试的接触时间内都能有效消灭粪肠球菌生物膜。0.02%和 0.01%的西曲溴铵在 2 分钟时也能达到消灭效果。统计分析显示，交替使用西曲溴铵和 CHX 比联合使用这两种药物的效果更好（P<.05）。
与单独使用西曲溴铵或 CHX 相比，联合使用西曲溴铵和 CHX 对粪肠球菌生物膜的效果更好，而交替应用的效果明显优于联合应用。
