17％EDTA与1％NaOCl组合用于根管超声冲洗抗菌效果的临床研究

目的研究17％EDTA＋1％NaOCl与超声波联合应用杀灭感染根管内厌氧菌的效果。方法将100例慢性根尖周炎患者共100颗患牙随机分为A组（2．5％NaOCl）、B组（1％NaOCl）、C组（17％EDTA＋1％NaOCl）、D组（17％EDTA）、E组（生理盐水）5组,每组各20颗患牙,采用手持器械预备根管后,分别采用2．5％NaOCl、1％NaOCl、17％EDTA＋1％NaOCl、17％EDTA、生理盐水超声法冲洗根管,根管预备前后分别取样进行厌氧培养。结果根管预备前后,五组根管内厌氧菌减少程度之间有显著性差异（P〈0．01）,其中C组（17％EDTA＋1％NaOCl组）厌氧茵的减少程度明显大于B组（1％NaOCl组）（P〈0．05）,显著大于D组（17％EDTA组）和E组（生理盐水组）（P〈0．01）,与A组（2．5％NaOCl组）之间无显著性差异（P〉0．05）。结论17％EDTA＋1％NaOCl与超声波联合应用可有效杀灭根管内的厌氧菌,其抗菌效果优于单独使用的1％NaOCl,与单独使用的2．5％NaOCl效果相近,是一种有效的根管冲洗液组合。     

不同冲洗方法对粪肠球菌感染根管的抗菌性研究

目的比较超声、Er,Cr：YSGG激光及Er：YAG激光辅助1%次氯酸钠（NaOCl）溶液冲洗对人离体牙根管表面粪肠球菌生物膜及根尖区不同深度牙本质小管内粪肠球菌的杀灭效果。 方法单直根管下颌前磨牙42颗,建立粪肠球菌生物膜感染的根管模型,采用随机字表法随机抽取2颗确定建成粪肠球菌生物膜感染根管模型,剩余40颗牙采用随机数字表法按随机对照原则分为5组,每组8颗。A组：5.25% NaOCl联合17%乙二胺四乙酸（EDTA）注射器冲洗;B组：0.9%氯化钠溶液注射器冲洗;C组：1% NaOCl溶液超声荡洗;D组：1% NaOCl溶液Er：YAG激光活化冲洗;E组：1% NaOCl溶液Er,Cr：YSGG激光活化冲洗。按分组进行处理后取样菌落计数,计算灭菌率。使用SPSS 17.0统计软件对实验数据进行方差齐性及正态性检验比较各组间和组内的灭菌率。 结果（1）组间比较：对根管壁表面,各组冲洗方法灭菌率比较,B组（5.74%）相似文献   

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。     

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。     

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。     

5种冲洗剂组合对前牙直根管清洁效果的比较

目的：比较5种冲洗剂组合对前牙直根管的清洁效果。方法：25颗离体直根管前牙,随机分为5组,不锈钢K锉常规法预备根管．应用5种冲洗剂组合进行冲洗。第1组：根管器械预备期间和预备结束后依次用1％NaOCl和3％H2O2冲洗;第2组：根管器械预备期间用1％NaOCl冲洗,预备结束后用17％EDTA冲洗;第3组：根管器械预备期间和预备结束后依次用1％NaOCl和17％EDTA冲洗：第4组：根管器械预备期间依次用17％EDTA和1％NaOCl冲洗,器械预备结束后用17％EDTA冲洗;第5组：根管器械预备期间依次用17％EDTA、1％Triton X-100(表面活性剂)和1％NaOCl冲洗．器械预备结束后用17％EDTA冲洗。每组冲洗剂剂量和冲洗时间均为22ml和7min。将牙纵劈后进行扫描电镜观察。结果：第1组,根管壁上见典型玷污层结构和大量杂质和残屑。第2组在根管冠、中1／3能部分去除玷污层．根尖1／3残留大量玷污层。第3组虽然能有效去除玷污层．但会引起牙本质小管中度腐蚀。第5组在根管冠、中1／3能部分去除玷污层,但根管壁上黏着大量杂质和残屑．此外还存在重度腐蚀现象。第4组根管清洁效果最好,且对牙本质小管无腐蚀性。结论：在严格控制冲洗时间和顺序的情况下,联合应用17％EDTA和1％NaOCl能有效去除玷污层．且不会腐蚀牙本质小管。     

酸性氧化电位水根管冲洗的抗菌效果

目的：研究酸性氧化电位水超声冲洗杀灭感染根管内厌氧菌的效果及其作为根管超声冲洗液的可行性。方法：将90例慢性根尖周炎患者共90颗患牙随机分为3组,每组各30颗患牙,第1组手持器械结合机用根管锉进行根管预备,常规针管式双氧水与生理盐水交替冲洗,第2、第3组同第一组进行根管预备,分别以生理盐水、酸性氧化电位水作为冲洗液进行根管超声冲洗,根管预备前后分别根管内取样进行厌氧菌培养。结果：第2组厌氧菌减少程度明显大于第1组（P〈0．05）;第3组厌氧菌减少程度大于第2组（P〈0．01）、显著大于第1组（P〈0．001）。结论：超声波在根管预备方面有一定的优势,酸性氧化电位水配合超声冲洗能有效杀灭感染根管内的厌氧菌,是一种理想的根管超声冲洗消毒液。     

根尖终末工作宽度对根管内细菌清除效果的体外研究

目的:比较不同的根尖预备终末工作宽度对根管内细菌清除效果的影响。方法:将已感染粪肠球菌的48颗离体上颌磨牙的远中颊侧根管标本随机分为6组,实验组分别预备根管至25#(A组)、30#(B组)、35#(C组)、40#(D组);对照组E、F组不进行机械预备而只进行冲洗。采用ProTaper机用镍钛锉和不锈钢K锉冠向下法预备根管。A、B、C、D、E组用1%次氯酸钠和17%EDTA冲洗根管,F组仅用生理盐水冲洗。根管预备前和预备后分别取样作细菌学培养计数,并做统计学分析。结果:预备冲洗后6组根管内的粪肠球菌量均显著下降(P<0.05),其中D组下降最明显。A、B组间差异无统计学意义,其余各组间比较均有显著性差异(P<0.05)。在实验组A、B、C、D组中,根管预备后阴性培养的百分率分别为0%、12.5%、37.5%和75%;对照组E、F组中均未获得阴性培养。结论:增大根尖预备终末工作宽度能提高根管内细菌清除的效果。但上颌磨牙远中颊侧根管预备至40#配合抗菌性冲洗液,尚不能完全清除根管内粪肠球菌。     

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。     

光活化消毒技术根管内消毒效果的研究

目的利用体外实验和临床试验评估光活化消毒技术（PAD）进行根管消毒的效果。方法体外选择30颗单根管牙根建立粪肠球菌ATCC29212感染模型,分为3组。用PAD技术进行根管消毒并取样,质量分数为2.5%的NaClO冲洗和生理盐水冲洗分别作为阳性和阴性对照组。临床选取50例慢性根尖周炎病例,随机分为2组。根管预备时质量分数为2.5%的NaClO溶液冲洗。预备后组1采用PAD消毒,组2用生理盐水冲洗。预备前后取样,所有样本接种于脑心浸液（BHI）培养基培养后记录菌落数。结果体外实验：PAD组细菌减少了99.86%,阳性对照组减少了100%,阴性对照组减少了96.94%。PAD组细菌回复10例均为阳性,阳性对照组6例,阴性对照组10例。临床试验：根管机械预备后细菌减少了99.98%。组1中PAD消毒后细菌培养均为阴性,组2细菌减少了36%。2组差异无统计学意义（P〉0.05）。结论 PAD单独使用可以降低根管内粪肠球菌的数量,但效果低于NaClO。临床PAD技术辅助根管预备可以进一步降低细菌的数量。     

三重抗生素糊剂对乳牙感染根管中微生物的影响

目的:探讨三重抗生素糊剂对乳牙根尖周炎不同分期感染根管中微生物样本的影响.方法:将2017年4月—2020年4月南京医科大学附属儿童医院口腔科收治的89例儿童乳牙根尖周炎患儿纳入研究,根据临床症状及根尖X线片,将患儿分为急性炎症组和慢性炎症组.收集感染根管内感染样本,对样本进行细菌鉴定、分离与纯化,分析2组患儿感染根管...     

Chlorhexidine gluconate

The aim of root canal treatment is to eliminate bacteria from the infected root canal and to prevent reinfection. Biomechanical cleaning and shaping greatly reduces the number of bacteria. Nevertheless, due to anatomical complexity of the root canal system, residues and bacteria cannot be removed completely. Therefore, various substances have been used during canal preparation to remove debris, necrotic tissue, bacteria and smear layer. The most common irrigant of choice is sodium hypochlorite (NaOCI): it is an effective antimicrobial agent and tissue solvent. However, NaOCI can be toxic. Chlorhexidine gluconate (CHX) is a broad-spectrum antimicrobial agent. As a root canal irrigant and intracanal medicament, CHX has an antibacterial efficacy comparable to that of NaOCI, and is effective against resistant bacterial strains. CHX may result in residual antimicrobial activity of the dentine surface after prolonged exposure of the root canal to CHX. CHX also has a low grade of toxicity. In this review CHX will be discussed in detail.     

In vitro evaluation by quantitative real-time PCR and culturing of the effectiveness of disinfection of multispecies biofilms in root canals by two irrigation systems

Objectives

The purpose of this in vitro study was by using quantitative real-time PCR and culturing to determine the effectiveness of two irrigation and cleaning systems in removing multispecies oral biofilms from root canals.

Material and methods

Twenty extracted human molars were instrumented to size #15/.02 and then cleaned with the GentleWave (GW) System. The teeth were autoclaved to provide the same sterile baseline. The molars were filled with mixed plaque suspended in BHI and centrifuged to inoculate the biofilms. After 2 weeks of incubation, the teeth were randomly divided into two treatment groups. In GW group (26 canals), the teeth were further instrumented to size #15/04, and in PiezoFlow (PF) group (30 canals) to #35/.04. The teeth were then cleaned either with GW System or ProUltra PiezoFlow Active Ultrasonic System using 3% sodium hypochlorite NaOCl, 8% EDTA, and sterile water as irrigants. Samples (S1, S2, and S3) for bacterial cultures were taken from 13 canals before and after instrumentation and after final cleaning. Quantitative real-time PCR was performed from all 56 canals, and universal bacterial, one genus, and one species-specific primers were used to determine the presence of microorganisms in samples from root canals before and after instrumentation and after final cleaning. Statistical analyses were performed using the Mann-Whitney U test with the significance level set at P < 0.05.

Results

Bacterial culturing from the canal samples revealed strong reduction of bacteria from S1 to S2 in both groups after instrumentation and irrigation with water only. No growth was detected in any of the S3 samples after cleaning in either group. A highly significant reduction in bacterial DNA was recorded by qPCR for both groups (P < 0.001). GW System showed more constant and a significantly higher reduction of total microbial DNA (P = 0.007), Enterococcus faecalis DNA (P = 0.011) and Streptococcus spp. DNA (P = 0.029) than the Ultrasonic System. The amount of residual microbial DNA calculated as an average of residual DNA in each individual canal in PF group was 1.99% and in GW group 0.09%.

Conclusions

While both systems demonstrated a highly effective reduction of intracanal bacterial DNA, the final total amount and variation in the number of residual bacterial DNA was significantly smaller in the GW group.

Clinical relevance

Elimination of microbes from the infected root canal system is regarded as the key for long-term clinical success. While both GentleWave and Ultrasonic Systems used with NaOCl and EDTA demonstrated a highly effective reduction of intracanal bacterial DNA; GW produced higher reduction and better predictability.

     

In vivo antimicrobial activity of 2% chlorhexidine used as a root canal irrigating solution.

The aim of the present study was to evaluate the in vivo antimicrobial activity of 2% chlorhexidine gluconate (FCFRP-USP) used as a root canal irrigating solution in teeth with pulp necrosis and radiographically visible chronic periapical reactions. Culture techniques and measurement of the inhibition zone were used. Twenty-two root canals of incisors and molars of 12 patients were used. After accessing the canal, the first root canal sample was collected with two sterile paper points that were transferred to a tube containing reduced transport fluid. The root canal was instrumented using chlorhexidine solution. A small sterile cotton pellet was placed at the root canal entrance, and the cavity was sealed with zinc oxide-eugenol cement. The canals were maintained empty for 48 h. Three sterile paper points were then introduced to absorb the root canal fluid (second sample). One paper point was placed on an agar plate inoculated with Micrococcus luteus ATCC 9341 and incubated for 24 h at 37 degrees C, and the other two were submitted to microbiological evaluation. Present in 10 cases at baseline, mutans streptococci was reduced by 100% at the second assessment. Treatment showed an efficiency of 77.78% for anaerobic microorganisms at the second assessment. These data suggest that chlorhexidine prevents microbial activity in vivo with residual effects in the root canal system up to 48 h.     

Effectiveness of castor oil extract on Escherichia coli and its endotoxins in root canals

This in vitro study sought to evaluate the effectiveness of castor oil extract used as an irrigating solution on Escherichia coli and its endotoxins in root canals. Sixty single-rooted teeth were prepared (using castor oil extract as irrigating solution) and divided into five groups (n = 12): Group 1 samples were treated with calcium hydroxide (Ca(OH)2), Group 2 samples were treated with polymyxin B, Group 3 samples were treated with Ca(OH)2 and 2% chlorhexidine gel (CHX), and Group 4 samples were treated with castor oil extract. A control group used physiological saline solution as an irrigant. Canal content samples were collected at four different times: immediately after instrumentation, seven days after instrumentation, after 14 days of intracanal medication, and seven days after removal of intracanal medication. A plating method was used to assess antimicrobial activity and the quantification of endotoxins was evaluated by the chromogenic Limulus lysate assay. Data were submitted to ANOVA and a Dunn test (a = 5%). Irrigation with castor oil extract decreased E. coli counts but had no effect on the level of endotoxins. Samples taken seven days after removal of medication revealed a significant reduction in endotoxin levels in Groups 3 and 4. Compared to the saline solution irrigation, castor oil extract decreased microorganism counts in root canals immediately after canal preparation. None of the medications used completely eliminated endotoxins in the root canal.     

Microbial status of apical root canal system of human mandibular first molars with primary apical periodontitis after "one-visit" endodontic treatment

OBJECTIVE: To assess the in vivo intracanal microbial status of apical root canal system of mesial roots of human mandibular first molars with primary apical periodontitis immediately after one-visit endodontic treatment. The residual intracanal infection was confirmed by correlative light and transmission electron microscopy. STUDY DESIGN: Sixteen diseased mesial roots of mandibular first molars were treated endodontically, each in one visit. Mesio-buccal canals were instrumented using stainless steel hand files and mesio-lingual canals with a nickel-titanium rotary system. The canals were irrigated with 5.25% sodium hypochlorite (NaOCl) during the instrumentation procedures, rinsed with 10 mL of 17% ethylenediamine tetraacetic acid (EDTA), and obturated with gutta-percha and zinc oxide eugenol cement. Thereafter, the apical portion of the root of each tooth was removed by flap-surgery. The specimens were fixed, decalcified, subdivided in horizontal plane, embedded in plastic, processed, and evaluated by correlative light and transmission electron microscopy. RESULTS: Fourteen of the 16 endodontically treated teeth revealed residual intracanal infection after instrumentation, antimicrobial irrigation, and obturation. The microbes were located in inaccessible recesses and diverticula of instrumented main canals, the intercanal isthmus, and accessory canals, mostly as biofilms. CONCLUSIONS: The results show (1) the anatomical complexity of the root canal system of mandibular first molar roots and (2) the organization of the flora as biofilms in inaccessible areas of the canal system that cannot be removed by contemporary instruments and irrigation alone in one-visit treatment. These findings demonstrate the importance of stringent application of all nonantibiotic chemo-mechanical measures to treat teeth with infected and necrotic root canals so as to disrupt the biofilms and reduce the intraradicular microbial load to the lowest possible level so as to expect a highly favorable long-term prognosis of the root canal treatment.     

Bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation

Abstract The purpose of this study was to assess the bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation. Root canal infection was induced in 50 single-rooted teeth in young dogs by removing the pulp and filling the canals with dental plaque. After 7 clays the root canals were instrumented under aseptic conditions with conventional hand instruments, a sonic vibratory device or an ultrasonic device. Sterile saline or 2.5% sodium hypochlorite was used as irrigating solution. Following instrumentation a sterile paper point was sealed into the root canals. After 7 d the root canals were reopened under aseptic conditions and the paper points were incubated for the demonstration of bacteria, using pre-reduced thioglycolate culture medium and anaerobic chambers. The results obtained with the different instrumentation techniques and irrigating solutions were compared by means of the Chi-square test. The results indicated that the sonic and ultrasonic devices were not more effective in the elimination of bacteria from the root canal than conventional hand instrumentation. Irrigation with sodium hypochlorite appeared to be more effective than saline in producing bacteria-free root canals; however, this difference was not statistically significant. Thus, it appeared that more than one appointment and the supporting action of an antibacterial medicament between appointments would be necessary to achieve bacteria-free root canals in infected teeth in a predictable manner.     

In vitro antimicrobial efficacy of MTAD and sodium hypochlorite

The purpose of this study was to compare the ability of a mixture of a tetracycline isomer, an acid, and a detergent (MTAD) with that of sodium hypochlorite (NaOCI) to disinfect human root canals that had been contaminated with whole saliva. One hundred and thirty-two root canals of extracted human teeth were cleaned and shaped using the passive step-back technique and rotary NiTi files. The smear layer was removed, and the teeth were autoclaved. Six autoclaved samples were transferred to sterile broth without contamination with saliva to serve as negative controls. Whole saliva was used to contaminate the root canals of the rest of the samples for 48 h. Six of these contaminated samples were irrigated with Brain Heart Infusion (BHI) broth and served as positive controls. The rest of the contaminated specimens were then divided into two experimental groups of 60 teeth each. In one group, the canals were irrigated with 1 ml MTAD, and the samples were immersed in 2 ml of the same solution for 5 min. In the second group, the specimens were similarly treated with 5.25% NaOCl. All samples were washed in BHI broth and then placed in another tube containing BHI broth and incubated for 96 h. Disinfection of the samples was determined based on presence or absence of turbidity in the broth 96 h later. Twenty-three of 60 teeth treated with NaOCl remained infected. Only one of 60 teeth treated with MTAD remained infected. Statistical analysis of the data using the Chi-square test showed a significant difference between the two groups (p < 0.0001).     

Dynamic recording of irrigating fluid distribution in root canals using thermal image analysis

AIM: To investigate the influence of the size and the depth of insertion of irrigating needles, and the diameter of the master apical file on flow distribution during fluid irrigation in root canals. METHODOLOGY: Stepback canal instrumentation was employed on seven extracted human single canal teeth. The size of the master apical files ranged from sizes 25, 30, 35, 40, 45, 50 to size 80 within the seven teeth, respectively. A thermal imaging system (ThermaCAM; National Instruments Co., Austin, TX, USA) was used to record the dynamic fluid distribution following root canal preparation. The dynamic fluid distribution was analysed during irrigation by insertion of different irrigating needle tips (23, 25 and 27 gauge) at various depths (3, 6 and 9 mm) from the root apex. The whole process of irrigation was recorded by a video camera and analysed by two observers separately. The success of the irrigation process was defined when the irrigant was able to flow into to the apical region immediately after injection. RESULTS: The aqueous irrigant was flushed into the apical region when a size 27 gauge irrigating needle was placed into a size 30 canal at a point 3 mm from the apical stop. When the same needle tip was placed 6 mm from the root canal apex, successful irrigation was achieved only in the canals prepared to size 50 or larger. When a size 25 gauge irrigating needle was placed 3 mm from the working length, the canal size had to be no <45 to allow for successful irrigation. When a size 23 gauge needle was placed at the same position, the canal needed to be prepared to size 50 to allow thorough irrigation of the apex. At 9 mm from the apical stop, none of the irrigating needles could achieve successful irrigation of any canal size. CONCLUSION: The flow distribution of root canal irrigation can be affected adversely by large diameter irrigating needles, by greater distances between the needle tip and the apical stop, and by narrow root canals.