两种根管冲洗方法联合不同冲洗液对粪肠球菌作用的体外研究

目的比较两种根管冲洗方法联合不同的冲洗液对抑制粪肠球菌的效果。方法将58颗单根管离体正畸牙根管预备后消毒,随机选取2颗检查灭菌效果,剩余56颗根管预备后接种粪肠球菌21d,按照冲洗方法不同随机分为超声根管冲洗组以及人工注射器冲洗组,每种冲洗方法中按照冲洗液的不同分为17%EDTA＋1%NaClO（A组）、17%EDTA＋2.5%NaClO（B组）、5.25%NaClO（C组）、0.9%NaCl（D组阳性对照组）,每组7个标本,分别于根管冲洗前、后进行细菌取样培养计数,并做统计学分析。结果无论在超声根管冲洗组或是人工注射器冲洗组,冲洗后各组根管内粪肠球菌量均显著下降（P〈0.05）,其中A、B、C三组冲洗液与D组相比较,差异均有显著性（P〈0.05）,A、B、C三组间两两对比,B组与A、C组差异具有显著性（P〈0.05）,A组与C组间差异无显著性（P〉0.05）;将超声根管冲洗法与人工注射器冲洗法相比较,发现在A组与C组中,两种方法有显著差异（P〈0.05）,B组中差异无显著性（P〉0.05）。结论 17%＋2.5%NaClO可有效清除根管内的粪肠球菌,其效果优于17%EDTA＋1%NaClO与5.25%NaClO,后两者间无显著差异;超声根管冲洗去除粪肠球菌的能力优于人工注射器冲洗。

Antimicrobial efficacy of two methods of irrigation and different endodontic irrigants using in vitro model infected by enterococcus faecalis

Objective The objective of this study was to evaluate the antibacterial efficacy of two root irrigating methods and different endodontic irrigants to disinfect human root canals that had been contaminated with Enterococcus faecalis.Methods The root canals of fifty-eight extracted premolar teeth were instrumented and autoclaved,two of them were transferred to sterile broth to serve as negative controls.Enterococcus faecalis was used to contaminate the root canals of the rest of the samples for 21 d,the teeth were randomly divided into two groups：ultrasonic irrigation group and syringe irrigation group,each group randomly and equally divided into four groups with different root canal irrigations.17% EDTA ＋ 1% NaClO was used for group A,while 17% EDTA ＋ 2.5% NaClO for group B,5.25% NaClO for group C,0.9% NaCl for group D（Positive control group）,The bacteria samples were collected with sterile paper points before and after irrigation.The CFU was counted and analyzed.Results The number of E.faecalis in root canals in each of groups was effectively reduced（P〈0.05） after irrigation,whether in the ultrasonic irrigation group or in the syringe irrigation group.The groups A、 B and C were significantlymore effective than group D（P〈0.05） .Group B was significantly more effective than group A and group C（P〈0.05）,while there was no significant difference between group A and group C（P〈0.05）;Group A and group C were significant difference（A：P〈0.05,C：P〈0.01） when we compared the ultrasonic irrigation group with the syringe irrigation group,while there was no significant difference in group B（P〈0.05） .Conclusion 17% EDTA ＋ 2.5% NaOCl irrigation has potential antibactericial effect on E.faecalis within root canals,the antibacterial efficacy of this irrigation was better than 17% EDTA ＋ 1% NaClO irrigation and 5.25% NaClO irrigation,while the other irrigations have no significant difference.The method of the ultrasonic irrigation was better than the method of syringe irrigation.