酸性氧化电位水在根管治疗中的应用研究

目的：评价酸性氧化电位水作为根管冲洗剂在灭菌和除去根管玷污层使根管达到无菌状态中的作用。方法：将108颗作根管治疗的单根患牙随机分为2组，实验组用酸性氧化电位水，对照组用过氧化氢液、生理盐水和乙二胺四乙酸二钠盐，分别在冲洗根管前后将根管内容物做细菌培养，检测有无菌落生成，再将20颗新鲜离体牙按上述方法分组处理，对每组患牙根管壁进行扫描电镜观察，评价除去根管玷污层效果。结果：在根管冲洗后，实验组和对照组根管内容物细菌培养阴性率无显著差异，在除去根管壁玷污层效果方面，2组也无显著差异。结论：酸性氧化电位水作为根管冲洗剂，可有效杀灭根管内细菌和去除根管玷污层，在临床上有较好的应用前景。     

EDTA凝胶与溶液对根管壁结构影响的比较研究

目的 研究EDTA凝胶与EDTA溶液在不同作用时间下,对根管玷污层及根管壁结构的影响.方法 采用因正畸需要新鲜拔除的健康上颌恒前磨牙7颗,常规根管预备后,取根中1/3段沿牙体长轴剖开,每根管分为两部分,每颗牙的两根管共获得4个标本,取其中1颗牙的4个标本作为对照组,其余每颗牙的4个标本分别纳入4个实验组.A组:15% EDTA水溶液冲洗1 min;B组: 15?TA水溶液冲洗5 min;C组:格兰凝胶涂布1 min;D组:格兰凝胶涂布5 min.扫描电镜观察各组根管内玷污层情况及牙本质结构的变化.结果 15?TA水溶液处理1 min即可有效去除根管玷污层,处理5 min则会引起管周和管间牙本质轻微脱矿;格兰根管凝胶处理1 min和5 min均能有效去除根管内玷污层,但均会引起牙本质过度脱矿和腐蚀.结论 格兰根管凝胶和EDTA水溶液均可去除根管玷污层,但持续作用于根管壁的时间不应超过1 min,以避免管壁过度脱矿.     

EGTA与EDTA溶液去除根管壁玷污层能力的比较

目的：比较EGTA与EDTA去除根管玷污层的能力，为临床应用提供实验依据。方法：新鲜拔除24颗牙齿分为4组，即：15％EDTA、5％EGTA、10％EGTA、15％EGTA。实验组又分为：根管预备后冲洗(简称：甲组)，边扩边冲洗组(简称：乙组)。常规开髓、拔髓后15％EDTA、5％EGTA、10%EGTA、15％EGTA分别冲洗根管，剖开根管后在扫描电镜下观察根管壁玷污层及根管壁牙本质小管开口情况。结果：15％EDTA无论在根管上、中、下1／3均能较理想去除根管壁玷污层，牙本质小管开口清楚、密集。5％EGTA去除根管玷污层效果欠佳，而10％、15％EGTA效果较好。结论：15％EDTA，10%、15％EGTA均有较好去除根管壁玷污层的能力，而且冲洗效果与注射针头进入深度密切相关。     

Biopure MTAD去除根管壁玷污层效能的体外实验研究

目的采用离体牙评价Biopure MTAD作为根管冲洗液去除根管壁玷污层的能力。方法将40颗人单根牙随机分为5组进行根管预备。各组根管预备过程中和预备完成时的冲洗液分别为：A组蒸馏水,B组5.25% NaClO和17% EDTA,C组1.3% NaClO,D组1.3% NaClO和Biopure MTAD,E组1.3% NaClO和3% EDTA。预备完后将样本纵向剖开,在扫描电镜下观察,评价根管壁玷污层和腐蚀情况。结果A组和C组实验样本整个根管壁都有玷污层覆盖。B、D、E组牙根冠和中1/3区根管壁玷污层均被有效去除,3组间无统计学差异（P＞0.05）;D组根尖1/3区根管壁基本无玷污层,与B、E组相比有统计学差异（P＜0.05）。B组根冠和根中1/3的根管壁的腐蚀度较大,与D、E组相比有统计学差异（P＜0.05）;根尖1/3区各组根管壁的腐蚀度无统计学差异（P＞0.05）。结论Biopure MTAD与1.3%的NaClO联合使用能更有效去除根管壁玷污层且对根管壁表面的结构无明显破坏。     

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。     

不同质量分数乙二胺四乙酸糊剂对根管壁不同区域玷污层的去除效果评价

目的研究不同质量分数乙二胺四乙酸（EDTA）糊剂去除根管壁玷污层的效果以及对根管壁的腐蚀作用。方法选择60颗离体单根管牙,用逐步后退法预备根管,预备后随机分成6组,采用不同质量分数的EDTA糊剂对根管进行处理,分别为5%、10%、15%、17%和20%EDTA糊剂,另设生理盐水组作为对照。处理时先将EDTA糊剂输送进根管内,作用3 min后以5.25%次氯酸钠溶液冲洗,次氯酸钠溶液用量为5 mL。处理后将牙根沿颊舌向纵向劈开,用扫描电镜观察根管壁不同部位玷污层的去除效果和牙本质的腐蚀状况,分别进行评分。结果随着EDTA糊剂质量分数的增加,对根冠1/3、根中1/3玷污层的去除效果明显增加。15%EDTA糊剂可以有效地去除根冠1/3和根中1/3的玷污层,根尖1/3去除效果稍差;对根管壁无明显的腐蚀破坏现象。17%和20%的EDTA糊剂对玷污层的去除效果明显,但对根管壁的结构造成了一定的腐蚀破坏。结论经不同质量分数的EDTA糊剂处理,根管壁玷污层的去除效果不同;质量分数大于17%的EDTA糊剂会对根管壁造成腐蚀。     

Nd:YAG激光照射根管后的形态学观察

目的：了解感染根管管壁牙本质的病变特点，根管预备及Nd：YAG激光照射对感染根管的作用。方法：选用单根患牙60颗，随机分为5组：对照组（治疗前感染根管）、根管预备组（用手用器械根管预备）、3个激光组（在常规根管预备后，采用3种不同能量参数照射1min），做扫描电镜观察。结果：对照组：感染根管牙本质小管形态不规则，排列紊乱。根管预备组：能去除病变的牙本质层，形成玷污层。50mj 10Hz激光组不能封闭牙本质小管。100mj 10Hz、150mj 10Hz激光照射1min根管壁呈熔融状态，去除了玷污层，牙本质小管封闭和半封闭。结论：激光剂量在100mj 10Hz或在此以上时，能有效清洁根管壁玷污层和封闭牙本质小管。     

声波与超声波器械配合不同冲洗液对根管清理效果的扫描电镜研究

目的：比较声波与超声波根管器械配合不同冲洗液预备根管的清理效果。方法：制作根管扫描电镜标本，观察根管玷污层分布和牙本质小管暴露情况，各标本的冠1／3、中1／3、根尖1／3区域各取10个500倍视野照相，分级评分(玷污层分数，SL)。统计学分析比较三种冲洗液条件下声波和超声波器械根管清理的差异。结果：仅以蒸馏水作冲洗液，声波不能有效清理碎屑与玷污层；25g／L NaClO冲洗，根尖1／3玷污层的去除超声组优于声波组，但未清除玷污层栓层；25g／L NaClO结合170g／L EDTA作冲洗液，玷污层去除显著且两组无显著差异，但根尖1／3差于根管中上段，超声组部分区域牙本质小管蚀刻与融合。结论：声波结合25g／L NaClO和170g／L EDTA可有效去除玷污层并达到与超声器械近似的根管清理效果，根管内荡洗去除玷污层栓层效果显著，且未对根管壁产生破坏，但有必要加强根尖部荡洗。     

去除玷污层的方法对根管充填密合性的影响

目的 观察根管冲洗剂与超声根管预备法能否去除玷污层以及去除玷污层对根管充填密合性的影响。方法 75颗离体牙随机分为3组,每组25颗。A组常规根管预备,扩锉中和扩挫后用生理盐水(NS)和3％双氧水(H_2O_2)冲洗;B组根管预备同A组,扩锉完成后用15％乙二胺四乙酸(EDTA)和5.25％次氯酸钠(NaOCl)交替冲洗;C组使用超声波根管扩大锉预备根管,NS冲洗。常规根管充填后用扫描电镜观察根管内壁表面形态,并做染液渗漏实验。结果 用手持器械预备根管,NS和3％H_2O_2冲洗根管,不能去除玷污层;使用15％EDTA和5.25％NaOCl交替冲洗根管,则可完全去除玷污层;用超声器械预备根管,对去除根管玷污层具有一定的作用。去除玷污层,充填材料进入牙本质小管,根尖微渗漏显著降低(P<0.05)。结论 去除玷污层,能增强充填材料边缘密合性和根尖封闭性,根尖徽渗漏显著降低。     

17% EDTA与脉冲Nd：YAG激光去除根管壁玷污层疗效的电镜研究

目的对17%EDTA与脉冲Nd：YAG激光对根管壁玷污层清除效果进行分析与比较。方法选取30颗新鲜单根成人离体牙,根管机械预备后随机分为三组,每组10例,分别给予5.25%NaClO冲洗（对照组）、17%EDTA＋5.25%NaClO冲洗以及5.25%NaClO冲洗＋Nd：YAG激光照射处理后,电镜下观察根管侧壁玷污层去除情况。利用计算机图像分析软件计算开放牙本质小管口面积/牙本质面积比。统计学方法采用单因素方差分析,α=0.05。结果EDTA冲洗及Nd：YAG激光照射后均可使根管侧壁玷污层明显减少,但EDTA冲洗对牙本质小管口开放作用明显优于Nd：YAG激光照射组及对照组（P〈0.01）。结论17%EDTA对根管壁玷污层的清除效果优于脉冲Nd：YAG激光,适合于临床广泛应用。     

Cleaning efficacy and dentin micro-hardness after root canal irrigation with a strong acid electrolytic water

The purpose of this study was to evaluate the cleaning effect of root canal walls using strong acid electrolytic water (SAEW) as a root canal irrigant, and to investigate the influence of SAEW on the root canal dentin by micro-hardness test. Forty-three single-rooted, single-canaled teeth were instrumented using standard step-back technique with K-files. Irrigation was performed using distilled water, 5.25% NaOCl and 3% H(2)O(2), SAEW, or 15% EDTA solution in five groups. Samples were prepared to be examined under a scanning electron microscope (SEM) and micro Vickers hardness (H(V)) test machine. Our results showed that the root cleaning effects of the combined use of SAEW and NaOCl solution as root canal irrigants were equivalent to those in the group with NaOCl and 15% EDTA. When SAEW was used for 1 min under ultrasonic vibration, no decreases in the hardness of dentin inside the root canal were detected.     

An SEM study of the effects of different irrigation sequences and ultrasonics

The root canals of 30 extracted human teeth with single canals were prepared biomechanically with hand instruments using a flaring technique. Three different irrigation regimes were used, with and without ultrasonic activation of a root canal file. The six irrigation sequences used in this study were as follows: Savlon, Savlon with ultrasound, EDTAC/NaOCl/EDTAC, EDTAC/NaOCl/EDTAC with ultrasound, NaOCl/EDTAC/NaOCl, and NaOCl/EDTAC/NaOCl with ultrasound. Scanning electron microscopic (SEM) examination of the prepared root canal walls showed a complete smear layer when Savlon was used. Ultrasound reduced the amount of smear with Savlon, but did not do so significantly with the other irrigation regimes. The most effective irrigation regime for removing smear layer and other debris was EDTAC/NaOCl/EDTAC. In all groups there was a significant decrease in cleaning efficiency as the apical end of the canal was approached.     

Cleaning effectiveness of root canal irrigation with electrochemically activated anolyte and catholyte solutions: a pilot study

AIM: The aim of this study was to evaluate the potential of electrochemically activated (ECA) anolyte and catholyte solutions to clean root canals during conventional root canal preparation. METHODOLOGY: Twenty extracted single-rooted human mature permanent teeth were allocated randomly into four groups of five teeth. The pulp chambers were accessed and the canals prepared by hand with conventional stainless steel endodontic instruments using a double-flared technique. One or other of the following irrigants was used during preparation: distilled water, 3% NaOCl, anolyte neutral cathodic (ANC) (300 mg L-1 of active chlorine), and a combination of anolyte neutral cathodic (ANC) (300 mg L-1 of active chlorine) and catholyte. The teeth were split longitudinally and the canal walls examined for debris and smear layer by scanning electron microscopy. SEM photomicrographs were taken separately in the coronal, middle and apical parts of canal at magnification of x800 to evaluate the debridement of extracellular matrix and at a magnification of x2500 to evaluate the presence of smear layer. RESULTS: Irrigation with distilled water did not remove debris in the apical part of canals and left a continuous and firm smear layer overlying compressed low-mineralized predentine. All chemically active irrigants demonstrated improved cleaning potential compared to distilled water. The quality of loose debris elimination was similar for NaOCl and the anolyte ANC solution. The combination of anolyte ANC and catholyte resulted in improved cleaning, particularly in the apical third of canals. The evaluation of smear layer demonstrated that none of the irrigants were effective in its total removal; however, chemically active irrigants affected its surface and thickness. Compared to NaOCl, the ECA solutions left a thinner smear layer with a smoother and more even surface. NaOCl enhanced the opening of tubules predominantly in the coronal and middle thirds of canals, whereas combination of ANC and catholyte resulted in more numerous open dentine tubules throughout the whole length of canals. CONCLUSIONS: Irrigation with electrochemically activated solutions cleaned root canal walls and may be an alternative to NaOCl in conventional root canal treatment. Further investigation of ECA solutions for root canal irrigation is warranted.     

A scanning electron microscopic evaluation of root canal wall cleanliness after calcium hydroxide removal using three irrigation regimens

AIMS: The aims of this in vitro study were to evaluate debris and smear layer elimination capability effectiveness of 5.25% sodium hypochlorite (NaOCl) after calcium hydroxide removal from the root canal and to determine if ethylenediaminetetraacetic acid (EDTA) and citric acid have any additional effects on debris and smear layer removal. METHODS AND MATERIALS: All irrigation regimens are associated with ultrasonics. Thirty-six pulpless single-rooted teeth were divided into three groups on the basis of the irrigation regimen, namely 5.25% NaOCl alone, 5.25% NaOCl with 17% EDTA pH 7 (NaOCl-EDTA), and 5.25% NaOCl with 50% citric acid (NaOCl-CA). All root canals were instrumented with the Protaper rotary system (Dentsply-Maillefer, Ballaigues, Switzerland) using a crown-down approach. The apical foramen of each tooth was enlarged to a size 30 with a 0.09 taper. After longitudinal sectioning, the dentin walls were microphotographed using scanning electron microscopy (SEM) at a 1500x magnification. Using a grid and a 5-step scale these microphotographs were scored by three investigators in order to evaluate debris and smear layer residuals. Data were statistically evaluated using Kruskal-Wallis and Mann-Whitney tests. RESULTS: In the coronal third the lowest score obtained with NaOCl-CA was similar to NaOCl-EDTA. When using NaOCl-EDTA, mean debris scores were similar to the control group (NaOCl) and lower than NaOCl-CA in the middle and apical thirds. Regarding the mean smear layer score, NaOCl-CA was the lowest in the coronal, middle, and apical thirds with a statistically significant difference (p < 0.001). CONCLUSION: When the total surface of the root was evaluated, NaOCl-EDTA was superior in removing debris, but the association of NaOCl-CA enabled the most effective removal of the smear layer.     

Cleaning efficacy of a new root canal irrigation solution: a preliminary evaluation

AIM: A new product, electro-chemically activated water, was compared to NaOCl for its cleaning effect on root canal walls. METHODOLOGY: Root canal treatment was carried out on two groups of extracted teeth with one of the irrigants being used in each group. The control group received no treatment. All teeth were split and the canal walls viewed in a scanning electron microscope. RESULTS: The canal walls of the control group were covered by debris and bacteria. Sodium hypochlorite produced clean surfaces with the dentinal tubules open in some areas and occluded by the smear layer in other areas; in some areas bacteria were visible inside or under the smear layer. Electro-chemically activated water produced markedly cleaner surfaces, removing the smear layer in large areas. CONCLUSIONS: The cleaning efficacy of electro-chemically activated water in root canals was considered to be superior to NaOCl.     

The effect of application time of EDTA and NaOCl on intracanal smear layer removal: an SEM analysis

AIM: To verify, under the scanning electron microscope (SEM), the influence of irrigation time with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) on intracanal smear layer removal. METHODOLOGY: Twenty-one extracted human permanent teeth with single straight root canals were included. The root canals of the teeth were instrumented and, at the end of preparation, were irrigated with 3 mL of 15% EDTA, followed by 3 mL of 1% NaOCl for 1 min (group 1), for 3 min (group 2), and for 5 min (group 3). The canals of teeth in group 4 (control) did not receive the final irrigation. The teeth were sectioned longitudinally and prepared for an SEM. The dentinal wall of cervical, middle and apical thirds was graded according to the amount of debris and smear layer remaining on the walls. The results were analysed using the Kruskal-Wallis and Conover-Inman tests. RESULTS: In all the canals of experimental groups irrigation with EDTA and NaOCl completely removed the smear layer from the cervical and middle thirds. In the apical third, the dentine surface were partially covered, particularly in the teeth of group 1, where there was significantly more smear layer when compared with the other thirds in the same group (P<0.007). However, the Kruskal-Wallis test showed overall that there were no significant differences between groups 1, 2 and 3 (P>0.05). CONCLUSION: In this limited laboratory study, canal irrigation with EDTA and NaOCl for 1, 3 and 5 min were equally effective in removing the smear layer from the canal walls of straight roots.     

Effectiveness of oxidative potential water as a root canal irrigant

AIM: The aim of this study was to evaluate the effectiveness of oxidative potential water (OPW) as an irrigant, based on its ability to remove the smear layer and/or debris from instrumented root canals. METHODOLOGY: One hundred and twenty root canals from extracted human maxillary incisors were instrumented using a conventional step-back technique with irrigation from sodium hypochlorite (NaOCl) or oxidative potential water (OPW). After instrumentation, the canals were irrigated by syringe or ultrasound using 15% EDTA or OPW as an irrigant. The volume of each irrigant used for syringe irrigation was 10, 20, and 30 mL, respectively, whilst the duration for ultrasonic irrigation was 1, 3, and 5 min, respectively. After irrigation, each root was split longitudinally in two with cutting pliers, and the specimens were prepared for SEM observation. The presence of debris and smear layer on each canal wall was assessed using a three-point scale for each parameter. RESULTS: Smear layer was effectively removed with EDTA both introduced via syringe and via ultrasonic irrigation. A similar effect was observed with OPW via syringe irrigation following instrumentation with 5% NaOCl. The canal walls in any of these cases showed open and patent dentinal tubules following smear layer removal. Some specimens irrigated with EDTA exhibited the effect of demineralization on the dentine resulting in funnelling of tubule orifices. Syringe irrigation was more effective in smear layer removal, except for ultrasonic irrigation with 15% EDTA, whilst ultrasonic irrigation was more effective in debris removal including the use of OPW as irrigant following instrumentation with 5% NaOCl. Neither syringe nor ultrasonic irrigation with OPW following instrumentation with OPW removed smear layer or debris effectively. CONCLUSIONS: The most effective irrigation technique for smear removal was 15% EDTA irrigation by means of syringe following instrumentation with 5% NaOCl solution. However, the most effective irrigation technique for debris removal was ultrasonic irrigation regardless of irrigant used. OPW irrigation by means of syringe following instrumentation with 5% NaOCl showed a similar effect to that of 15% EDTA irrigation for removal of smear layer and debris.     

In vitro cleaning ability of root canal irrigants with and without endosonics

A variety of methods have been used to evaluate the cleanliness of root canals after endodontic preparation and irrigation. Few irrigation agents other than sodium hypochiorite (NaOCl) have been tested in conjunction with endosonics. The purpose of this study was to examine the cleaning ability of water, NaOCl, Hibiscrub and a biological washing liquid when used as intracanal irrigants, with and without endosonics. Two methods of evaluation were employed to assess the root canal cleanliness after endodontic preparation. A total of 56 teeth, divided into eight groups, were prepared manually using the step-down technique. Each irrigating agent was used in two experimental groups, with and without endosonics. Two additional teeth which received neither instrumentation nor irrigation served as the controls. The teeth were split longitudinally and the state of cleanliness of the root canal was assessed by scoring the amount of stained organic debris and smear layer. It was demonstrated that the results of debris and smear layer scoring were significantly influenced by the type of irrigant and whether endosonics had been used. All agents exhibited similar cleaning ability when introduced manually. With endosonics, NaOCl yielded significantly less stainable debris (P < 0.05) than the other groups which showed no significant difference. The ability to remove the smear layer was enhanced, but at some distance short of the working length, by endosonics for all irrigants tested. None of the solutions tested was able to produce a canal wall that was free of smear layer.     

Comparison of the Efficacy of Maleic Acid and Ethylenediaminetetraacetic Acid in Smear Layer Removal from Instrumented Human Root Canal: A Scanning Electron Microscopic Study

IntroductionThe aim of this study was to assess, by scanning electron microscopic (SEM) analysis, the ability of 17% EDTA and 7% maleic acid in the removal of the smear layer from the human root canal system.MethodsEighty single-rooted human anterior teeth were subjected to standardized root canal instrumentation (step-back technique) and were irrigated with 2.5% NaOCl after each instrument. Based on the final irrigating solution used, samples were divided randomly into three groups: (1) the EDTA group: 17% EDTA+ 2.5% NaOCl (n = 30), (2) the maleic acid group: 7% maleic acid + 2.5% NaOCl (n = 30), and (3) the control group: 0.9% saline (n = 20). After final irrigation, teeth were prepared for SEM analysis to evaluate the cleaning of the coronal, middle, and apical thirds of radicular dentin by determining the presence or absence of smear layer. The data was statistically analyzed using the Kruskall-Wallis test.ResultsAt the coronal and middle thirds, there was no significant difference between EDTA and maleic acid. Both were equally efficient in the removal of smear layer. In the apical third, maleic acid showed significantly better smear layer removing ability than EDTA.ConclusionFinal irrigation with 7% maleic acid is more efficient than 17%EDTA in the removal of smear layer from the apical third of the root canal system, which is a crucial area for disinfection.