次氯酸钠对根管内粪肠球菌杀菌效果的体外实验

目的评价次氯酸钠对根管内粪肠球菌的杀菌效果。方法将45个离体前磨牙的感染根管标本分为6组，1、2组用5．25％及2．5％次氯酸钠冲洗，3组用0．9％NaCl冲洗，4、5组在根管预备时辅以5．25％及2．5％次氯酸钠冲洗，6组在根管预备时辅以0．9％Nacl冲洗。冲洗前、冲洗后即刻及冲洗后72h分别取样培养。结果6组根管内的细菌量均显著下降。1、2组差异无统计学意义（P〉0．05），但均好于3组（P〈0．05）。4、5和6组差异均有统计学意义（P〈0．05）。根管冲洗后培养72h均有细菌生长。结论2．5％次氯酸钠基本可达到更高浓度的灭菌效果，但是经过机械预备和次氯酸钠化学消毒后的根管内仍有细菌残留。     

五种冲洗液对根管内粪肠球菌抗菌效果的体外实验

目的评价五种冲洗液对根管内粪肠球菌的杀菌效果。方法建立粪肠球菌根管内感染模型,将40个感染根管标本随机分为5组,每组8颗牙。器械预备时分别采用5.25%NaClO（A组）、2.5%NaClO（B组）、1%NaClO（C组）、17%EDTA（D组）、17%EDTA＋1%NaClO（E组）冲洗根管。冲洗前、冲洗后即刻及冲洗后72h分别取样,37℃下CO2孵育箱中培养,48h后计数菌落数（CFU/ml）。结果冲洗后5组根管内的粪肠球菌量均显著下降（P〈0.05）,其中A组与其余各组间差异均有显著性（P〈0.01）;B组与C组、D组间差异有显著性（P〈0.05）,与E组间差异无显著性（P〉0.05）;C组与D组、E组间差异有显著性（P〈0.05）;D组与E组间差异有显著性（P〈0.05）。根管冲洗后培养72h均有细菌生长。结论5.25%NaClO抗菌效果最强;17%EDTA＋1%NaClO的抗菌效果优于1%NaClO,与2.5%NaClO抗菌效果相近似。     

四种冲洗剂对根管内粪肠球菌清除效果的体外实验

目的比较常用的根管冲洗剂对根管内粪肠球菌感染的清除效果。方法建立粪肠球菌根管内感染模型，实验组用4种常用的化学冲洗剂、对照组用0．9％NaCl溶液冲洗根管。冲洗前、后计数根管内的细菌量，检测残余细菌并观察72h细菌复苏情况。结果化学冲洗剂的杀菌效果明显好于0．9％NaCl溶液（P〈0．05），2．5％次氯酸钠及2％氯己定明显好于3％H2O2（P〈0．05）。结论2％氯己定、2％氯胺-T的杀菌效果与2．5％次氯酸钠相似，3％H2O2杀菌效果较弱。     

次氯酸钠对粪肠球菌杀菌效果的体外研究

目的体外评价次氯酸钠(NaOCl)对粪肠球菌的杀菌效果及浓度依赖关系。方法采用纸片扩散法药敏实验观察NaOCl对粪肠球菌的抑菌环大小(mm),直接接触法观察NaOCl对粪肠球菌的灭活时间。结果5.25%NaOCl的抑菌环直径最大,4.00%与2.50%、1.00%与0.50%差异无显著性。5.25%NaOCl在30s内可杀死全部粪肠球菌,2.50%NaOCl杀死粪肠球菌需要15min,随浓度的下降,杀死细菌所需要的时间延长。结论高浓度NaOCl的效果优于低浓度NaOCl,2.50%NaOCl基本可满足临床要求。     

几种根管冲洗液组合对粪肠球菌感染根管体外抗菌研究

目的：比较本实验室研制的根管润滑剂与不同浓度次氯酸钠组合用于粪肠球菌感染根管预备冲洗的抗菌效果。方法：将145颗单根管人离体牙消毒,随机选取5颗置于无菌培养基中培养作为阴性对照,其余140颗接种粪肠球菌4周,按照不同的冲洗组合随机分为14组,使用ProTaper器械按照冠根向深入法进行机械预备,分别在预备冲洗前、预备冲洗中和预备冲洗后进行细菌取样培养计数,并进行统计学分析。结果：与双氧水联合生理盐水组以及蒸馏水对照组相比,各处理组在冲洗过程中与冲洗结束后,均不同程度的降低了根管中的细菌的数量,其中含5.25%次氯酸钠的四种组合处理后菌数减少最为明显,较其它各组差异显著。结论：本实验室研制的根管润滑剂与5.25%次氯酸钠组合抗菌效果最佳,与G lyde凝胶配合次氯酸钠组没有显著差异。     

不同类型激光对根管内粪肠球菌消毒作用的研究进展

近年来，越来越多的新技术被用于牙科治疗中，其中激光的应用更是获得广泛关注。在根管消毒方面，已有许多研究证实，不同类型激光器在运用于根管消毒时，对粪肠球菌均有一定杀菌作用，可考虑作为辅助技术协助完成根管治疗。现今，常应用于根管消毒的激光器包括Nd：YAG、Er：YAG、Er，Cr：YSGG激光及KTP激光和半导体激光等，这些激光器的工作原理相互之间都略有不同，其作用效果也存在一定差异。本文就不同类型激光对根管内粪肠球菌消毒作用的研究进展作一综述。     

再感染根管内粪肠球菌生物膜的研究进展

粪肠球菌是顽固性和继发性根管感染中最易分离到的细菌,其主要致病机制之一是形成生物膜.笔者下面就再感染根管内粪肠球菌的分离与鉴定、影响粪肠球菌生物膜形成的相关因素等作一综述.     

不同根管冲洗液和冲洗方法对粪肠球菌清除作用的体外研究

目的 比较不同冲洗液和冲洗方法对根管内粪肠球菌的清除效果。方法 建立120颗人完整单根管前磨牙粪肠球菌感染根管模型,随机分组,分别采用不同冲洗液(0.9% NaCl,0.5% NaClO,3% NaClO)及冲洗方法(注射针头冲洗,超声荡洗,RinsEndo系统处理,超声荡洗协同RinsEndo系统联用)进行根管清理。无菌吸潮纸尖取样,平板菌落计数法计算CFU值,计算细菌清除率,运用SPSS 22.0软件进行统计分析,P<0.05时差异具有统计学意义。结果 使用0.9% NaCl及0.5% NaClO冲洗液时,注射针头冲洗组细菌清除率明显低于超声荡洗及RinsEndo系统处理组(P<0.001);使用3% NaClO冲洗液的各组不同的冲洗方法,细菌清除率的差异无统计学意义(P=0.556)。而无论采用哪种冲洗方法,3% NaClO溶液的细菌清除效果均优于0.5% NaClO溶液和0.9% NaCl溶液(P<0.001)。结论 不同根管冲洗液在一定程度上会影响根管冲洗方法对根管内粪肠球菌的清除效果。     

不同根管冲洗方式对粪肠球菌生物膜清除效果评价

目的 比较不同根管冲洗方式对粪肠球菌感染根管预备、冲洗的清除效果,评价不同根管冲洗液残余药量的抗菌效果,为临床上选择根管冲洗方法提供参考。方法 将32颗离体牙（前磨牙、单根管）消毒,接种粪肠球菌60 d,随机分为4组（第1组：生理盐水;第2组：生理盐水+超声1 min;第3组：1%NaOCl;第4组：1%NaOCl+超声1 min）,使用ProTaper器械按照冠向下法进行根管预备,并在预备冲洗前及预备至F2进行冲洗后分别取样、计数,进行统计学分析。将预备好的离体牙再次消毒,随机分为2组,分别浸泡生理盐水和1%NaOCl;浸泡30 min后取出,置于接种粪肠球菌标准菌株（ATCC33186）的培养液内,分别在培养2、6、24、48 h时取样、计数。采用SPSS19.0软件包对数据进行统计学分析。结果 4组在预备至F2冲洗结束后,根管中的细菌数量均不同程度降低,其中,使用1% NaOCl结合超声冲洗1 min,几乎可完全去除根管内的细菌。经1% NaOCl浸泡的牙根样本内的细菌,在培养48 h时后总量少于生理盐水。结论 1%NaOCl是有效的根管冲洗液,用于根管化学预备后的残余液体,也可发挥有效的抗菌效果。联合使用超声器械,可以使其抗菌效果最大化。     

Carisolv应用于根管冲洗对根管内粪肠球菌抗菌作用的体外研究

目的：分析Carisolv祛龋凝胶作为根管冲洗剂对粪肠球菌（E．faecalis）离体牙根管感染模型的抗菌效果。方法：60颗牙体完整、发育正常的人单根管前磨牙,用ProTaper手用器械将建立根管感染模型的离体牙根管预备至F2后,建立粪肠球菌体外根管感染模型。随机分为5组,分别使用Carisolv凝胶、5．25％次氯酸钠溶液、EDTA凝胶、2％氯亚明溶液、0．9％氯化钠溶液进行根管冲洗,对根管冲洗前后的根管进行菌落计数,比较各种冲洗剂的抗菌作用。结果：5种冲洗剂在根管预备冲洗后细菌数量都显著性低于冲洗前（P＜0．001）。Carisolv组、氯亚明组、次氯酸钠组冲洗后根管的细菌数量没有显著性差异（P＞0．05）,低于EDTA组和氯化钠组（P＜0．01）。结论：Carisolv凝胶作为根管冲洗剂具备抗菌作用,其抗菌作用强于EDTA凝胶和0．9％氯化钠溶液。     

Bacteriophages induced from lysogenic root canal isolates of Enterococcus faecalis

Introduction:  Bacterial viruses play crucial roles in the pathogenesis of many systemic diseases. They are known to inhabit the oral cavity, both as free virions and as prophages in lysogenic bacterial strains; however, there has been no report of bacteriophages in endodontic infections. In this study, we sought to detect, isolate, and describe temperate bacteriophages harbored by Enterococcus faecalis strains isolated from endodontic infections.
Methods:  Ten E. faecalis strains were isolated from root canals of teeth undergoing retreatment following unsuccessful endodontic therapy. Mitomycin C was used to induce any prophages present in the bacterial isolates. The induced phages were purified and examined using electron microscopy. The DNA extracted from one of the phage isolates was subjected to restriction endonuclease digestion and agarose electrophoresis analysis.
Results:  Lysogeny was demonstrated in 4 of the 10 E. faecalis strains. Three of the lysogenic strains yielded phages exhibiting a Siphoviridae morphology, with long, non-contractile tails 130 nm in length, and spherical/icosahedral heads 41 nm in diameter. The virus induced from the fourth lysogenic E. faecalis strain had a contractile tail characteristic of Myoviridae. Restriction endonuclease analysis of Nsi I and Nde I DNA fragments from one of the Siphoviridae phage isolates (phage φEf11) indicated a genome size of approximately 41 kbp.
Conclusion:  This is the first report of lysogenic bacteria and their inducible viruses in infected root canals.     

利用粪肠球菌感染根管模型评价不同根管封闭剂的抗菌效果

目的 体外建立粪肠球菌根管感染模型,比较3种生物陶瓷类根管封闭剂的抗菌性能.方法 选择人单直根管的离体前牙48颗,接种粪肠球菌并孵育4周以构建体外根管感染模型.完成根管成形和清理后,随机将样本分为3个实验组和2个对照组,每组按照如下方法进行根管充填:A组,Biodentine+牙胶;B组,iRoot BP+牙胶;C组,...     

再治疗根管粪肠球菌生物膜形成与临床表现相关性分析

目的检测粪肠球菌形成生物膜的能力,探讨其生物膜形成能力与临床表现之间的关系。方法采用96孔板法形成生物膜,结合结晶紫染色,检测临床样本中分离的53株粪肠球菌形成生物膜的能力,分析其生物膜形成能力与患牙临床表现之间的关系。结果53株粪肠球菌中,40株（75.47%）具有生物膜形成能力;在患牙的多种临床表现中,瘘道与再治疗根管粪肠球菌生物膜形成具有相关性,结果具有统计学意义（P＜0.05）。结论再治疗根管中,无瘘道的患牙分离出来的粪肠球菌生物膜形成能力强于有瘘道的患牙,临床治疗中应予以注意。     

根管冲洗剂QMix冲洗性能的研究进展

根管预备时,采用单纯机械预备方法无法完全去除根管内感染,化学冲洗是消除根管内感染不可或缺的步骤。理想的根管冲洗剂应具备彻底清除玷污层、润滑根管、有效杀菌、对组织无毒性且不损伤牙齿结构的特点。现有的根管冲洗剂尚不能同时满足上述所有要求。QMix是由乙二胺四乙酸（EDTA）、氯己定（CHX）和表面活性剂混合组成的根管冲洗剂。QMix能够有效去除玷污层,杀菌性强且有持续的抗菌作用,细胞毒性小且生物相容性好,对牙本质的着色浅,对牙本质微硬度的影响小。此外,QMix还可以提高根管封闭剂的润湿性且不影响其粘接性能。本文比较QMix与其他常用的根管冲洗剂（如次氯酸钠、CHX、EDTA、SmearClear、MTAD等）在去除玷污层、对牙本质作用、对根管封闭剂的影响、细胞毒性、抗菌作用等方面的作用特点,将目前对QMix的研究成果作一综述。     

Short-term antibacterial activity of root canal sealers towards Enterococcus faecalis

AIM: To investigate the antimicrobial activity of root canal sealers on Enterococcus faecalis, either allowing or avoiding direct contact between sealers and bacteria. METHODOLOGY: Filter paper discs were immersed in standardized E. faecalis suspensions and exposed to freshly mixed sealers (MCS, AH Plus, Grossman's sealer, Sealapex, Apexit) in teflon wells for 30 min, with or without a filter membrane placed between filter paper discs and sealers (membrane-restricted contact test and direct contact test, respectively). After exposure, the filter paper discs were transferred to vials containing phosphate-buffered saline (PBS) and glass beads, and vigorously vortexed. PBS with resuspended bacterial cells was serially diluted and 25 microL droplets were seeded on TSA plates. The plates were incubated in air at 37 degrees C for 24 h and colony-forming units were counted. Using alpha = 0.05 as level for statistical significance, the data obtained were analysed using Student's t-test. RESULTS: In the direct contact test, MCS and AH Plus killed the bacteria to a level below the detection limit. They were followed in decreasing order of efficacy by Grossman's sealer, Sealapex and Apexit. In the membrane-restricted contact test, the sealers ranked: MCS, AH Plus, Grossman's sealer, Apexit and Sealapex, in descending order of antibacterial potency. MCS, AH Plus and Grossman's sealer significantly reduced the number of viable bacteria in both tests. Sealapex and Apexit were not statistically different from control. CONCLUSIONS: MCS, AH Plus and Grossman's sealer were effective in reducing the number of cultivable cells of E. faecalis. Calcium hydroxide-based sealers, Sealapex and Apexit were ineffective in this short-term experiment.     

Evaluation of the effectiveness of sodium hypochlorite used with three irrigation methods in the elimination of Enterococcus faecalis from the root canal, in vitro

The effectiveness of 4.0% sodium hypochlorite (NaOCl) used with three irrigation methods in the elimination of Enterococcus faecalis from the root canal was tested in vitro . Root canals contaminated with E. faecalis were treated as follows: (i) irrigation with 2 mL of NaOCl solution and agitation with hand files; (ii) irrigation with 2 mL of NaOCl solution and ultrasonic agitation; (iii) irrigation with NaOCl alternated with hydrogen peroxide. Contaminated canals irrigated with sterile saline solution served as the control. Paper points used to sample bacteria from the root canals were transferred to tubes containing 5 mL of brain heart infusion (BHI) broth. Tubes were incubated and the appearance of broth turbidity was indicative of bacteria remaining in the root canal. There were no statistically significant differences between the experimental groups. However, NaOCl applied by the three methods tested, was significantly more effective than the saline solution (control group) in disinfecting the root canal.     

顽固感染根管内粪肠球菌的致病机制及其控制方法进展

根管治疗是治疗牙髓感染的常用方法。成功的根管治疗依赖于良好的根管预备、冲洗消毒以及对三维根管系统的严密充填,其中通过清除根管系统内感染生物膜、细菌毒素以防止高度复杂的根管系统再次感染是根管治疗成功的关键。本文从根管内严苛环境下粪肠球菌的致病机制、根管顽固感染的根尖周组织炎症与局部免疫、感染根管控制方法进展等方面,对这一主题进行阐述。     

评价两种低温等离子体对粪肠球菌生物膜作用的体外实验研究

目的 比较辉光放电和介质阻挡放电两种低温等离子体装置产生的大气压低温等离子体对根管内粪肠球菌生物膜的杀菌效果。方法 在120颗离体牙的根管内部培养粪肠球菌生物膜,培养时间为7 d。将离体牙随机分为12个组,其中,10组分别接受介质阻挡放电和辉光放电这两种大气压低温等离子体装置处理离体牙根管,每种装置各处理5组,每组处理时间分别为2、4、6、8、10 min;另外2组为两种不同装置的单纯气体对照组。采用菌落形成单位计数法比较两种装置对根管内生物膜的杀菌效果,通过光谱测量仪分析两种装置的等离子体活性成分。结果 介质阻挡放电装置比辉光放电装置对根管内粪肠球菌生物膜的杀菌效果更好,不同时间段二者存活的细菌数量均有统计学差异（P<0.05）,而且随着处理时间延长优势更加明显。发射光谱显示两种装置的低温等离子体活性物质成分一致,但激发态Ar原子的群峰总体上表现为介质阻挡放电装置是辉光放电装置的2倍。结论 介质阻挡放电装置产生的低温等离子体杀灭根管内粪肠球菌生物膜更具优势。     

Survival of Enterococcus faecalis in root canals ex vivo

AIM: The hypotheses tested in this study were that: (i) Enterococcus faecalis can survive long-term entombment in root filled teeth without additional nutrients, (ii) initial cell density influences the survival of E. faecalis in instrumented root canals and (iii) gelatinase-production capacity influences the survival of E. faecalis in root canals. METHODOLOGY: The root canals of 150 extracted single canal teeth were instrumented to apical size 60 and divided into six groups of 25. Within each group 10 canals were inoculated with either gelatinase-producing E. faecalis OG1-S and the other 10 with its gelatinase-defective mutant E. faecalis OG1-X. Five canals per group were kept as uninoculated controls. The root canals in groups 1 and 2 were inoculated with 10(6) bacteria, incubated for 48 h at 37 degrees C then filled with gutta-percha and zinc-oxide eugenol sealer. Root canals were inoculated with 10(6), 10(5), 10(4) and 10(3) bacteria in groups 3-6, respectively, and left unfilled. All teeth were sealed coronally with glass-ionomer cement. After 6- (groups 1, 3-6) and 12-month (group 2) incubation at 37 degrees C in 100% humidity, root fragments were analysed for presence of E. faecalis, using culture, polymerase chain reaction and histological methods. RESULTS: Viable E. faecalis was recovered from all root filled teeth and from 95-100% of unfilled inoculated teeth. Initial cell density and gelatinase production did not influence the recovery of viable E. faecalis (P > 0.05; chi-square test). Enterococcus faecalis 16S rRNA gene products were present in all inoculated teeth and absent in all noninoculated controls. Dentinal tubule infection was evident under light microscopy in sections from inoculated teeth after 48-h, 6- and 12-month incubation. CONCLUSIONS: Enterococcus faecalis inoculated into root canals maintained viability for 12-months ex vivo. The clinical implications are that viable E. faecalis entombed at the time of root filling could provide a long-term nidus for subsequent infection.