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。     

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。     

醋酸氯己定和次氯酸钠对粪肠球菌抑菌作用的体外研究

目的：体外药敏试验评价醋酸氯己定（CHA）和次氯酸钠（NaCIO）对粪肠球菌的抑菌效果。方法：采用纸片扩散法药敏试验观察不同浓度醋酸氯已定和次氯酸钠对粪肠球菌的抑菌环直径（mm）,方差分析评价药物对粪肠球菌的抑菌效果。结果：2％的CHA抑菌环最大;1％CHA、0．5％CHA和5．25％NaCl0的抑菌环直径无显著性差异,均大于2．5％NaCl0;NaCl0抑菌环直径随浓度的增大而增大。0．5％NaCl0抑菌环与对照组无显著性差异。结论：低浓度CHA即可达到高浓度NaCl0的抑菌效果,高浓度NaCl0的抑菌效果优于低浓度NaCl0。     

Er:YAG激光联合次氯酸钠对粪肠球菌杀菌效果的研究

目的:比较掺铒钇铝-石榴石脉冲(Er:YAG)激光联合不同浓度次氯酸钠对根管内粪肠球菌杀菌效果的研究。方法:选择新鲜拔除的人单根管离体前磨牙建立粪肠球菌根管感染模型75个,随机分为5组,每组15个,分别进行如下处理:A组:5.25%次氯酸钠单独冲洗;B组:Er:YAG激光+5.25%次氯酸钠冲洗;C组:1%次氯酸钠单独冲洗;D组:Er:YAG激光+1%次氯酸钠冲洗。E组:空白对照。采集5组根管内的细菌进行培养计数并对结果进行卡方检验(Chi-square test)。结果:A、B、D三组均能完全杀灭根管内的粪肠球菌;C组未能完全杀灭根管内的粪肠球菌。15个培养皿中有11个可见粪肠球菌菌落。A、B、D三组间杀菌效果无差异且均显著优于C组。结论:高浓度次氯酸钠可以完全杀灭根管内的粪肠球菌,低浓度次氯酸钠不能完全杀灭根管内的粪肠球菌;Er:YAG激光可以显著增强低浓度次氯酸钠的杀菌作用。     

根管冲洗液对粪肠球菌作用的研究进展

粪肠球菌是一种最常见的导致根管治疗失败的细菌,如何控制根管内的粪肠球菌是研究的热点。根管冲洗剂是杀灭和抑制粪肠球菌的有效方法之一,本文就根管内粪肠球菌的感染特点、常用根管冲洗液以及冲洗剂联合使用对其的作用等方面作一综述。     

不同冲洗液对根管超声冲洗效果的实验研究

目的：探讨不同冲洗液对根管超声冲洗效果的影响。方法：选择单根管离体牙68颗,随机分为4组,每组17颗,常规根管预备后进行超声冲洗,A组：0．5％次氯酸钠、B组：3％双氧水、C组：1％氯亚明、D组：0．5％次氯酸钠和0．2％氯己定混合液,其中每组12颗超声冲洗后根管充填,并测量根尖微渗漏长度;每组剩余5颗电镜扫描观察。结果：根尖微渗漏D组与A、B、C组比较有显著差异（P〈0．05）,A、B、C三组组间无统计学意义;电镜扫描观察根中1／3牙本质小管口打开数目,D组优于A、B、c组（P〈0．05）。结论：0．5％次氯酸钠和0．2％氯己定混合液配合超声能获得好的冲洗效果。     

羧甲基壳聚糖及其复合物对根管内粪肠球菌的作用评价

目的：探讨羧甲基壳聚糖(carboxymethyl chitosan,CMCS)及其复合物对根管内粪肠球菌的抑菌作用,为在根管治疗方面的应用积累数据。方法：建立粪肠球菌感染根管模型,随机分为A、B、C、D 4组,分别将2%氯己定、140 mg/mL羧甲基壳聚糖氯己定合剂、5 mg/mL羧甲基壳聚糖、Ca(OH)2糊剂注满相应组的各样本根管腔内,培养7 d。封药前、后取样,分别接种在BHI琼脂平皿上,48h后计数菌落形成单位(CFU/mL)。采用SPSS13.0软件包对数据进行统计学分析。结果：封药前,各组根管内细菌量差异无显著性(P>0.05)。封药后即刻,各组根管内细菌量的减少差异显著(P<0.05)。A组与B组的抗菌活性显著优于C组、D组。结论：2%氯己定与140 mg/mL羧甲基壳聚糖氯己定合剂对粪肠球菌具有较强的抗菌活性。     

茶多酚、MTAD和次氯酸钠液抑制粪肠球菌及其生物膜的作用比较

目的:检测中药茶多酚、MTAD、52.5 g/L次氯酸钠抑制根管壁粪肠球菌生物膜的能力,并分析中药茶多酚作为根管冲洗液的可行性。方法:采用微孔板滴定法检测茶多酚,MTAD和52.5 g/L次氯酸钠液对粪肠球菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),采用琼脂扩散实验检测3种抗菌剂对粪肠球菌的抑菌圈。通过建立粪肠球菌感染根管3周和6周的模型,分别用茶多酚、MTAD和52.5 g/L次氯酸钠液对粪肠球菌感染后的根管进行处理,然后对根管壁生物膜中的细菌生存情况进行定性定量分析,比较这3种根管冲洗液抗粪肠球菌生物膜的能力。结果:MIC、MBC和琼脂扩散实验显示:3组冲洗剂对粪肠球菌均有抑制作用。在粪肠球菌感染根管3周的生物膜中,MTAD和次氯酸钠液可以完全抑制粪肠球菌生物膜,茶多酚处理后虽仍有粪肠球菌生长,但明显低于生理盐水处理组的细菌生存数,差异有统计学意义(P<0.05)。在粪肠球菌感染根管6周的生物膜中,次氯酸钠液可以完全抑制细菌生长,茶多酚和MTAD作用后仍有活菌生长,但与对照组相比,细菌生存数均显示了8个log值的下降,差异有统计学意义(P<0.05)。结论:52.5 g/L次氯酸钠液具有很强的抑制根管内粪肠球菌生物膜作用,而茶多酚和MTAD也具有一定的抑制粪肠球菌生物膜的能力。     

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。     

EDTA与次氯酸钠联合应用对根管内粪肠球菌清除效果:体外研究

目的:评价17%EDTA联合1%次氯酸钠对根管内粪肠球菌的清除效果.方法: 将40 个离体前牙的感染根管标本随机分为5组,器械预备时分别辅以冲洗液冲洗根管.其中A、B、C组分别用5.25%、2.5%及1%次氯酸钠冲洗,D组用17%EDTA联合1%次氯酸钠冲洗,E组用0.9%NaCl冲洗.冲洗前、后计数根管内的细菌量,并观察72 h细菌复苏情况.结果: 5 组根管内的细菌量均显著下降(P<0.01),其中D组与A、C组间差异有显著性(P<0.05),与B组间差异无显著性(P>0.05).结论: 17%EDTA联合1%次氯酸钠可有效清除根管内粪肠球菌, 其效果优于1%次氯酸钠,与2.5%次氯酸钠相近似.     

复方冰硼冲洗液用于根管冲洗的清洁性实验研究

目的：评价复方冰硼冲洗液用于根管冲洗的清洁性。方法：收集40个新鲜拔除的单根管前磨牙,随机分为4组,每组10个。采用不锈钢K锉和逐步深入预备技术预备根管,分别使用4组冲洗液进行根管冲洗。Ⅰ组为5mL复方冰硼冲洗液;Ⅱ组为2.5mL 5.25%次氯酸钠溶液（NaOCl）＋2.5mL 17%乙二胺四乙酸溶液（EDTA）;Ⅲ组为2.5mL 3%双氧水＋2.5mL 0.9%生理盐水;Ⅳ组为5mL 0.9%生理盐水。最后用3mL生理盐水冲洗根管。采用数码照相机照相和扫描电镜观察,分别比较根尖1/3区和根中1/3区根管内的碎屑百分数和牙本质小管开口数。结果：在根尖1/3区,Ⅳ组碎屑百分数明显高于其他3组,Ⅳ组牙本质小管开口数明显少于其他3组（P〈0.05）。在根中1/3区,Ⅳ组的碎屑百分数明显高于Ⅱ组,Ⅰ、Ⅱ组牙本质小管开口数明显多于Ⅲ、Ⅳ组（P〈0.05）。结论：Ⅰ、Ⅱ、Ⅲ组的根管冲洗效果好于Ⅳ组,冲洗液的化学特性非常重要。冲洗液的清洁性排序为：NaOCl组、复方冰硼冲洗液组、双氧水组、生理盐水组。复方冰硼冲洗液被认为是可能用于根管冲洗的中药冲洗液。     

NaOCl and EDTA irrigating solutions for endodontics: SEM findings.

Premolars roots of humans were manually instrumented with K-type files and irrigated with different solutions to evaluate the rate of cleaning of endodontic surface. Root canals irrigated with 0.9% saline solution or H2O2 (10 volumes) showed the presence of predentin and amorphous smear layer. Thick smear layer was always present on endodontic walls rinsed with 5% solution of NaOCl. Specimens treated with 0.2% solution of EDTA showed partially clean dentinal tubules orifices and remnants of a thin smear layer. Occasional uninstrumented areas of the same roots presented smear layer remnants and predentin with calcified bacteria. The root canals irrigated with NaOCl and EDTA solutions alternated after each instrument showed at the dentin surface thick smear layer: only few dentinal tubules orifices were visible. Endodontic surface of root canals irrigated with NaOCl during instrumentation and finally rinsed with EDTA solutions showed the most homogeneous ultrastructural pictures: partially clean dentinal orifices were detectable in the whole canals.     

Effectiveness of three endodontic irrigants at various tubular depths in human dentin

Bacteria from infected root canals can invade dentinal tubules, thus dentin disinfection is an important aspect of endodontic therapy. This study compares three endodontic irrigants for efficiency in killing bacteria established within human dentinal tubules. Root canals in extracted teeth were prepared and sterilized. Broth cultures of Enterococcus faecalis were allowed to grow within the canals to penetrate dentinal tubules. The infected canals were exposed individually to each of the irrigants for 1 min. Irrigants were 0.525% sodium hypochlorite, Tubulicid (0.2% EDTA), and 0.12% chlorhexidine (Peridex). Sterile water was the control. Viable bacteria were analyzed by drilling incrementally into dentin from the cementum toward the canal. Smaller diameter drills were used for each depth. Shavings were cultured at three depths, for each of three root levels: coronal, midroot, and apical. Although considerable variation occurred between roots, sodium hypochlorite seemed to be superior. Tubulicid and Peridex were better than water. More bacteria remained viable at greater distances from the pulp. These observations apparently apply to all levels in the canal.     

Antibacterial efficacy of calcium hydroxide and chlorhexidine gluconate irrigants at 37 degrees C and 46 degrees C

This study investigated the ability of two endodontic irrigants to eliminate Enterococcus faecalis from dentinal tubules, and whether their antimicrobial action was enhanced by heat. The lumens of disks prepared from extracted bovine roots were infected with E. faecalis and incubated for 72 h. Specimens were then filled with saline, 10% calcium hydroxide (Ca(OH)2), or 0.12% chlorhexidine gluconate (CHX) at 24 degrees C or 46 degrees C and incubated at 37 degrees C or 46 degrees C. The samples were then pulverized and plated to quantify residual bacteria. No statistical difference (p > 0.05) in bacterial growth was seen between the two saline groups, or between the two medication groups at a given temperature. CHX and Ca(OH)2 at either temperature produced significantly less growth than either saline group, and CHX or Ca(OH)2 at 46 degrees C produced significantly less growth than either group at 37 degrees C. Heat enhanced the antibacterial action of both experimental irrigants against E. faecalis, but heating saline produced no increase in bactericidal effect.     

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。     

In vitro disinfection of dentinal tubules by various endodontics irrigants

Effectiveness of endodontic irrigants within dentinal tubules of human teeth was evaluated. Mid-sections of single-rooted teeth were prepared into dentin wedges. The pulpal sides of the sections were exposed to Micrococcus luteus or Bacillus megaterium that grew into the tubules. Irrigants used in the study included: 0.525% NaOCl, 0.12% chlorhexidine, RC Prep, 0.5% betadine iodine, and sterile H2O (as a control). Pulpal surfaces were exposed to an irrigant and then rinsed in sterile water. The samples were then cracked, exposing a fresh surface. Culture of the exposed dentin surfaces showed that selected irrigants reached to the far ends of the dentinal tubules in a concentration sufficient to kill 100% of the M. luteus. However B. megaterium was neither killed nor apparently inhibited by any irrigant. We conclude that endodontic irrigants permeate throughout dentinal tubules, but their effectiveness is dependent on the type of bacteria found within the tubules.     

Efficacy of various concentrations of NaOCl and instrumentation techniques in reducing Enterococcus faecalis within root canals and dentinal tubules

AIM: To evaluate the efficacy of 0.5%, 2.5% and 5.25% sodium hypochlorite (NaOCl) as intracanal irrigants associated with hand and rotary instrumentation techniques against Enterococcus faecalis within root canals and dentinal tubules. METHODOLOGY: A total of 180 extracted human premolar teeth were infected for 21 days with E. faecalis. The specimens were divided into 12 groups, as follows: group 1: 5.25% NaOCl + Hybrid technique (Valdrighi et al. 1998); group 2: 5.25% NaOCl + nickel-titanium (NiTi) rotary technique 4 mm shorter than the apex (by FOP-UNICAMP); group 3: 5, 25% NaOCl + NiTi rotary technique (Hero 642); group 4: 2.5% NaOCl +Hybrid technique; group 5: 2.5% NaOCl + NiTi rotary technique 4 mm shorter than the apex; group 6: 2.5% NaOCl + NiTi rotary technique (Hero 642); group 7: 0.5% NaOCl + Hybrid technique; group 8: 0.5% NaOCl + NiTi rotary technique 4 mm shorter than the apex; group 9: 0.5% NaOCl + NiTi rotary technique (Hero 642); group 10: sterile saline solution + Hybrid technique; group 11: sterile saline solution + NiTi rotary technique 4 mm shorter than the apex; group 12: sterile saline solution + NiTi rotary technique (Hero 642). Canals were sampled before and after preparation. After serial dilution, samples were plated onto brain heart infusion (BHI) agar, and the colony forming units (CFU) that were grown were counted. The teeth were sectioned into three thirds and dentine chips were removed from the canals with conical burs. The samples obtained with each bur were immediately collected into test tubes containing BHI broth, and were incubated at 37 degrees C and plated onto BHI agar. The CFU were counted and analysed. RESULTS: At all depths and thirds of the root canals and for all techniques used, 5.25% NaOCl was shown to be the most effective irrigant solution tested when dentinal tubules were analysed, followed by 2.5% NaOCl. No differences among concentrations in cleaning the canals were found. CONCLUSIONS: Especially at higher concentrations, NaOCl, was able to disinfect the dentinal tubules, independent of the canal preparation technique used.     

Observation of bacteria and fungi in infected root canals and dentinal tubules by SEM

Abstract The aim of this study was to observe the root canal flora and possible penetration of microorganisms into dentinal tubules in teeth with necrotic pulps. Ten infected maxillary and mandibular molars with periapical lesions were extracted and fixed in 2.5% phosphate-buffered glutaraldehyde solution for nine days. After separation from the crowns, longitudinal grooves were cut in the roots, and they were split into two halves. The specimens were prepared for SEM. The root canals and the dentinal tubules of the fractured dentin were scanned systematically from the cervical to the apical area of the root. Cocci and rods were seen in 6 specimens. Penetration of bacteria into the dentinal tubules ranged from 10 to 150 μm. In 4 specimens, the root canals were heavily invaded by yeasts. The antimicrobial effect of routinely used endodontic disinfectants also on yeasts may be considered in persistent root canal infections.     

Antimicrobial substantivity of chlorhexidine-treated bovine root dentin

Previous studies have demonstrated antimicrobial substantivity in root canal dentin up to 7 days after treatment with chlorhexidine. This in vitro study assessed the antimicrobial substantivity of chlorhexidine-treated bovine root dentin over a period of 21 days. Sixty standardized bovine root sections were randomly divided into three equal groups, and their canals immersed in one of the following solutions: (i) sterile saline; (ii) 2.5% NaOCl; or (iii) 0.2% chlorhexidine (CHX). Half the specimens in each group were treated with the solution for 5 min and the other half for 7 days. After solutions were removed, the specimens were incubated at 37 degrees C in Brain Heart Infusion broth containing Enterococcus faecalis (ATCC 29212). A fresh inoculum was added to the broth every other day over a 21-day period. The canals were then enlarged with sterile burs, and the dentin shavings collected and cultured for the presence of cultivable bacteria in the dentinal tubules. Specimens treated with CHX for 7 days demonstrated significantly less dentin colonization by E. faecalis than the other specimens. CHX has potential as an intracanal medicament, if it can be applied for a period of at least 7 days.