不同浓度次氯酸钠根管超声冲洗的实验研究

目的：比较不同浓度次氯酸钠溶液的根管冲洗效果。方法：选择根尖发育完成的单、直根管前磨牙50颗,随机分为5组,每组10颗。不锈钢K锉和逐步深入技术根管预备后,分别使用蒸馏水,0．5％、1％、2％或5．25％次氯酸钠进行根管超声冲洗。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：蒸馏水组在根尖和根中1／3区的碎屑百分数明显高于其他4组,牙本质小管开口数明显少于其他4组;去除蒸馏水组后,0．5％次氯酸钠组在根中1／3区的碎屑百分数明显高于其他3组,牙本质小管开口数明显少于其他3组。结论：4种不同浓度次氯酸钠溶液的根管冲洗效果均好于蒸馏水;0．5％次氯酸钠根管冲洗的效果比其他3种较高浓度的次氯酸钠差。     

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。     

根管超声冲洗效果的扫描电镜研究

目的用扫描电镜的方法评价根管超声冲洗的效果。方法选择直单根管前磨牙20颗，随机分为超声冲洗组（U组）和注射器冲洗组（S组）。用逐步后退法预备根管后，2组选用不同方法，均用40ml2．5g／L NaOCI最后冲洗根管。样本去冠后沿牙长轴纵向劈开，扫描电镜观察，记录电镜照片上牙本小管开口的数目并对均数进行统计学分析。结果U组牙本质小管开口数明显多于S组（P〈0．05）；2组相应部位比较，颈1／3处牙本质小管开口数之间的差异无统计学意义（P〉0．05），U组在根中1／3和根尖1／3的牙本质小管开口数数明显多于S组（P〈0．05）。结论用2．5g／L NaOCl超声根管冲洗效果优于用注射器冲洗。     

XP-endo Finisher锉对根管内壁玷污层清除效果的体外研究

目的 评估XP-endo Finisher（XPF）锉与被动超声冲洗（PUI）对根管内壁玷污层的清除效果。方法 选择60颗离体单直根管下颌前磨牙,距根尖16 mm处截冠,采用S3镍钛锉预备到3S,根据终末处理方式不同将样本随机分成6组。A组：3 mL 3%次氯酸钠溶液联合XPF处理1 min;B组：3 mL 3%次氯酸钠溶液联合XPF处理1 min,再用4 mL 17%乙二胺四乙酸（EDTA）溶液冲洗1 min;C组：3 mL 3%次氯酸钠溶液联合PUI处理1 min;D组：3 mL 3%次氯酸钠溶液联合PUI处理1 min,再用4 mL 17%EDTA溶液冲洗1 min;E组：3 mL 3%次氯酸钠溶液30号侧方冲洗针冲洗1 min;F组：3 mL 3%次氯酸钠溶液30号侧方冲洗针冲洗1 min,再用4 mL 17%EDTA溶液冲洗1 min。采用扫描电子显微镜观察玷污层形态,并比较根尖1/3区、根中1/3区牙本质小管开口数。结果 A、C、E组实验样本整个根管壁都有玷污层覆盖,A组与C组牙本质小管开口数明显高于E组（P<0.05）,而A组与C组的差异无统计学意义（P>0.05）;F组根中区、B组和D组根尖区有少量玷污层覆盖,牙本质小管开放或半开放;F组根尖区可见玷污层,牙本质小管封闭或半封闭;B和D组根中区根管壁玷污层均被有效去除;在根尖1/3区和根中1/3区,B组与D组牙本质小管开口数高于其他4组（P<0.05）,而B组和D组间的差异无统计学意义（P>0.05）。结论 XPF锉对根管内壁玷污层的清洁效果与PUI无明显差异,可用于根管预备后提高根管清洁效果。     

不同冲洗剂对桩道内壁牙本质形态的影响

目的:比较3种冲洗液5.25%NaClO溶液和15%EDTA溶液、0.2%的氯己定溶液对桩道内壁形态的影响。方法:筛选18颗新鲜拔出单根管前磨牙,在釉牙骨质界上2 mm处截冠,随机分成3组。常规根管充填、桩道预备后分别用A:蒸馏水(对照组)、B:5.25%NaClO溶液和15%EDTA溶液、C:0.2%的氯己定溶液冲洗桩道,将牙根纵向劈开。选取能够较好展示根管壁的一侧作为样本,扫描电子显微镜观察根中1/3的牙本质表面,按Gorman分类法记分,记录数据并统计分析。结果:A组玷污层较厚,有中等量杂质及碎屑残留,牙本质小管极少或不可见;B组清洁程度最高,玷污层极少,极少量杂质及碎屑残留,牙本质小管开口较清晰;C组有部分玷污层,少量杂质及碎屑残留,牙本质小管开口部分可见。各组差异有统计学意义(P<0.05)。结论:冲洗处理对桩道对牙本质表面有影响,应用5.25%NaClO溶液和15%EDTA溶液冲洗效果最好。     

穿心莲纳米乳液用于根管冲洗的清洁性实验研究

目的:评价穿心莲纳米乳液用于根管冲洗的清洁性。方法:收集50个新鲜拔除的单根管前磨牙,随机分为5组。采用镍钛锉冠向下法预备根管,分别使用5组冲洗液进行根管冲洗。A组为穿心莲纳米乳液,B组为穿心莲提取液,C组为1%次氯酸钠(NaClO),D组为3%NaClO,E组为0.9%的生理盐水。最后每组分别用17%乙二胺四乙酸二钠(EDTA)、生理盐水冲洗根管。采用数码相机和扫描电镜观察,分别比较根尖、根中和根冠1/3区根管内碎屑百分数和玷污层评分。结果:根尖1/3:E组碎屑百分数和玷污层明显高于其他4组,C组玷污层评分明显高于A组和D组(P<0.05)。根中1/3:E组碎屑百分数和玷污层评分明显高于其他4组,C组碎屑含量明显多于A组和D组(P<0.05)。根冠1/3:E组碎屑百分数和玷污层评分明显高于其他4组,C组玷污层评分明显高于D组(P<0.05)。结论:冲洗液的清洁性排序：3%NaClO、穿心莲纳米乳液、穿心莲提取液、1%NaClO、生理盐水。穿心莲纳米乳液被认为是可能用于根管冲洗的中药冲洗液。     

不同冲洗剂对桩腔预备后牙本质清洗能力及树脂突的影响

目的比较不同根管冲洗剂对桩腔预备后根管内牙本质表面玷污层去除和牙本质小管开放的影响。方法将30个完成根管充填的上颌前牙经桩腔预备后,根据根管冲洗剂不同随机分成A、B、C 3组。A、B、C组分别使用3%过氧化氢（H2O2）、15%乙二胺四乙酸（EDTA）、15%EDTA加3%次氯酸钠（NaClO）作为冲洗剂。冲洗后每组选取8个标本通过扫描电镜（SEM）观察牙本质表面玷污层和牙本质小管开放情况,另选2个标本在粘接纤维桩后用于观察树脂突。结果A、B、C组牙本质清洁效果（Berg值）分别为3.89±0.36、1.77±0.30、1.25±0.21;牙本质小管直径分别为（2.53±0.19）、（3.11±0.23）、（3.83±0.52）μm。3组间牙本质表面清洁效果和牙本质小管开口差异均有统计学意义（P<0.05）。C组出现明显的牙本质过蚀。各组间的树脂突形成有很大差异,以B组最优。结论桩腔预备后用15%EDTA冲洗桩腔能有效去除玷污层,使牙本质小管开放,利于树脂黏固剂有效渗入牙本质小管和胶原纤维网。     

二氧化氯作为根管超声冲洗剂的清洁效果

目的 评价二氧化氯用作根管超声冲洗剂的清洁效果.方法 选择30颗离体单根管前磨牙,截去牙冠后随机平分成A、B、C三组,用手持不锈钢器械逐步后退法进行根管预备,超声波冲洗,冲洗剂分别为蒸馏水、1.0%次氯酸钠和0.1%二氧化氯溶液.完成根管预备后纵行劈开牙根,扫描电镜观察,在根管颈1/3、中1/3、尖1/3各部位随机拍照,在电镜照片上评定根管壁上碎屑和玷污层记分,计数牙本质小管开放数目,并进行统计学分析.结果 A、B、C各组碎屑记分差异无统计学意义(P＞0.05);B、C两组的玷污层明显少于A组,差异有统计学意义(P＜0.01);牙本质小管开放数也明显多于A组,差异有统计学意义(P＜0.01),但B、C两组之间差异无统计学意义(P＞0.05).结论 0.1%二氧化氯溶液用作根管超声冲洗剂,具有良好的清洁作用,对碎屑和玷污层的去除能力不亚于1.0%次氯酸钠,明显优于蒸馏水.     

不同方法预备根管对根管治疗后牙齿冠渗漏的影响

目的采用3种不同方法预备根管,评价其对根管治疗后牙齿冠渗漏的影响。方法48颗单根管离体牙随机分为4组,使用不同的根管预备方法去除根管壁的玷污层。A组为对照组,采用生理盐水和过氧化氢溶液冲洗根管;B组采用乙二胺四乙酸（EDTA）凝胶和5.25%次氯酸钠溶液冲洗;C组采用Odontoson-M型超声波治疗仪荡洗;D组采用脉冲Nd: YAG激光照射。每组取2颗牙,于扫描电子显微镜（SEM）下观察冠部玷污层的去除情况;其余10颗牙采用Obtura Ⅱ高温注射式热牙胶垂直加压法充填根管,氧化锌丁香油黏固剂封闭根管口,浸于质量浓度20 g·L-1亚甲基蓝溶液中染色7 d,脱水脱钙制作透明牙标本,体视显微镜下测量染料渗入的深度。结果SEM观察：A组
整个根管内壁被覆玷污层及大量碎屑,牙本质小管被堵塞;B组与C组根管内壁清洁,玷污层消失,牙本质小管开放;D组根管内壁牙本质小管封闭或半封闭,玷污层熔融消失。A、B、C、D组染料渗入深度分别为（2.15±0.38）、（1.75±0.28）、（2.04±0.40）、（1.73±0.36）mm。A组的渗入深度明显高于B、D组,其差异有统计学意义（P<0.05）。结论使用不同的方法预备根管去除玷污层,可以减少根管治疗后牙齿的冠渗漏。     

不同冲洗方法与机用镍钛锉结合应用对根管壁的清洁作用

目的 应用扫描电镜来观察四种不同冲洗方法与机用镍钛锉结合预备根管，对根管壁的清洁效果。方法 将40颗前牙分成4组，采用不同的冲洗方法：A组：生理盐水．B组：2．5％次氯酸钠；C组：Glyde File Prep和2．5％次氯酸钠交替冲洗；D组：2．5％次氯酸钠冲洗，预备完成后，用无菌纸尖蘸上次氯酸钠和Glyde File Prep交替处理根尖区。在根管的三个不同深度采用扫描电镜记录牙本质碎屑、玷污层和牙本质小管情况。结果 A、B组与C、D比较组存在着明显的增厚的玷污层，开放的小管数目也明显减少，A组样本与其它冲洗方法组有统计学差异。结论 Glyde File Prep与机用镍钛锉合用预备根管能获得良好的术前清洗效果。     

根管超声冲洗效果的临床评价及实验研究

目的　评价根管超声冲洗技术的清洗效果 ,为临床应用和推广提供理论依据。方法6 0例根尖周病患者按就诊顺序随机分为超声冲洗组 (U组 )和注射器冲洗组 (S组 ) ,比较两组术中疼痛率、根管及侧支根管的充填情况。选择离体直单根管前磨牙 6 0颗 ,随机分为U、S两组 ,4 0颗进行组织学观察 ,2 0颗用于扫描电镜研究。结果　U组侧支根管充填率高于S组 (P <0 0 1) ;U组术中疼痛发生率为 3 3% ,S组为 13 3% (P >0 0 5 )。U组根管内有机碎屑的含量明显少于S组 (P <0 0 1) ,且U组根管壁上牙本质小管开口数目明显比S组多 (P <0 0 5 )。结论　超声冲洗技术可以较好地清洁根管 ,使术中疼痛发生率趋向于减少 ,侧支根管充填率提高     

Efficacy of final irrigation--a scanning electron microscopic evaluation

The purpose of this in vitro study was to determine the degree of removal of pulpal remnants and smear layer from root canals after final irrigation with three different solutions. During instrumentation the step-back preparation and 1% NaOCl were used. The final 4-min, 30-ml irrigation varied as follows: group I, 10 ml of 1% NaOCl + 10 ml of 10% citric acid + 10 ml of distilled water; group II, 15 ml of 0.5% NaOCl + 15 ml of EDTA-T; and group III, 10 ml of 5% NaOCl + 10 ml of 3% H2O2 + 10 ml of 5% NaOCl. Scanning electron microscopic photomicrographs were evaluated for the mean number of visible open dentinal tubules by three observers. The largest number of visible tubules in the three groups was in the cervical third, followed by the middle and apical thirds. There was no statistically significant difference between groups I and II when third was compared with third; however, groups I and II had significantly more visible dentinal tubules than group III.     

Effect of three different time periods of irrigation with EDTA-T, EDTA, and citric acid on smear layer removal

OBJECTIVE: An in vitro study was conducted to evaluate the effect of EDTA-T, 17% EDTA, and 10% citric acid on the removal of smear layer from root canal dentin after final irrigation for 3, 10, and 15 min. STUDY DESIGN: Root canals of 90 extracted human canines were divided into 9 groups of 10 teeth; each group received a final irrigation with one of the irrigants for the established time intervals. After irrigation, the teeth were split and prepared for SEM analysis to determine the number of open dentinal tubules. RESULTS: There were statistically significant better results (P <.05) when irrigation with 10% citric acid for 3 min was compared to 10 and 15 min, and when irrigation with EDTA for 3 min was compared to 15 min. In all cases, irrigation for 3 min presented the greatest number of open dentinal tubules. There were no significant differences (P>.05) for the 3 time intervals of irrigation for EDTA-T, although there were a greater number of open tubules at 3 min. CONCLUSION: These 3 irrigants were effective at the shortest time tested and did not demonstrate an improved effect with an increase in time.     

Cleanliness of dentinal tubules following gutta-percha removal with and without solvents: a scanning electron microscopic study

Aim  To determine the influence of solvents on gutta-percha and sealer remaining on root canal walls and in dentinal tubules.
Methodology  The root canals of 70 teeth were prepared chemomechanically to apical size 40. In group 1 ( n  = 10; control group), the canals remained unfilled. In groups 2–4 ( n  = 20 each), the canals were filled using lateral compaction with gutta-percha and sealer. Removal of root fillings was undertaken after 2 weeks using Gates Glidden burs and hand files without solvent (group 2), with eucalyptol (60 μL; group 3) and with chloroform (60 μL; group 4) to size 50. After further irrigation using sodium hypochlorite and ethylenediaminetetraacetic acid, the roots were split, photographed and scanning electron microscopy (SEM) was performed. The number of filled dentinal tubules (SEM) and the surface covered by root filling remnants (photographs) were evaluated for the coronal, middle and apical third of each root half. Statistical analysis was performed via mixed model for clustered data followed by Tukey's test.
Results  After pooling the results of all thirds of the canal, open tubules were more prevalent in the control group, followed by the nonsolvent group, the eucalyptol group and the chloroform group ( P  < 0.05 between all groups). Less surface was covered by root filling remnants in the nonsolvent group than in the eucalyptol group and the chloroform group ( P  < 0.05); again, fewer remnants were found in the control group than in all other groups ( P  < 0.05).
Conclusions  Solvents led to more gutta-percha and sealer remnants on root canal walls and inside dentinal tubules.