新型纳米银对感染根管内粪肠球菌生物膜的杀灭效应

Anti-biofilm efficacy of SilverSol/H2O2 against in-situ Enterococcus faecalis biofilms in root canals

目的:研究新型纳米银SilverSol/H2O2在感染根管内的抗生物膜效应。方法:收集离体上颌中切牙41颗,根管预备、灭菌,接种粪肠球菌后厌氧培养6周。利用扫描电镜(scanning electronic microscopy,SEM)观察细菌生物膜的结构。将样本随机分为5组,分别采用0.9%NaCl,2.5、5和10 ppm SilverSol/H2O2,及6%NaClO冲洗根管2 min,利用激光共聚焦显微镜(confocal laser scanning microscopy,CLSM)对生物膜进行序列扫描,计算死菌百分比,并测量生物膜厚度。结果:SEM观察结果显示根管表面覆盖着具有三维立体结构的粪肠球菌生物膜。CLSM观察结果显示,SilverSol/H2O2可不同程度地杀灭生物膜细菌并瓦解其立体结构,浓度越高,杀灭能力越强(P<0.05),但均弱于6%NaClO(P<0.01)。除6%NaClO外,各组生物膜厚度均在14.58~15.86μm之间,无统计学差异(P>0.05)。结论:SilverSol/H2O2能一定程度上瓦解根管生物膜结构并杀灭细菌,可作为一种有效的根管辅助冲洗液。

Objective:To investigate the anti-biofilm efficacy of SilverSol/H2O2 in root canals ex vivo.Methods:Forty-one single-rooted central incisors were instrumented,autoclaved and inoculated with Enterococcus faecalis(E.faecalis)for 6 weeks.One specimen was split for scanning electronic microscopy(SEM)to confirm the presence and maturation of biofilms.The remaining specimens were randomly divided to five groups,including 0.9%NaCl,2.5 ppm SilverSol/H2O2,5 ppm SilverSol/H2O2,10 ppm SilverSol/H2O2 and 6%NaClO.Percentages of dead bacteria and biofilm thickness were evaluated by confocal laser scanning microscopy(CLSM).Results:The ubiquity of E.faecalis biofilms on dentine surfaces of the root canals was confirmed by SEM.The percentages of dead bacteria were significantly affected by the"irrigant"(P<0.01).Only 6%NaClO eliminated biofilms and significantly reduced their thickness.Conclusion:SilverSol/H2O2 were less adept than 6%NaClO at killing biofilm bacteria and disrupting biofilm structure in root canals.