冠渗漏研究概况

根管治疗完成后根管系统冠根方的良好封闭可阻止微生物及其毒纱进入根尖周组织，冠封闭不良时，细菌及其营养物可经冠方进入髓腔，再沿根充材料渗漏进入根尖周组织导致治疗失败。冠渗漏是根管治疗失败的重要原因，正愈来愈受到研究者广泛重视。本文就冠渗漏引起根管治疗失败，冠渗漏与根尖渗漏的关系、冠渗漏的影响因素和预防措施等方面的研究现状作一综述。     

冠渗漏研究概况

根管治疗完成后根管系统冠根方的良好封闭可阻止微生物及其毒素进入根尖周组织,冠封闭不良时,细菌及其营养物可经冠方进入髓腔,再沿根充材料渗漏进入根尖周组织导致治疗失败。冠渗漏是根管治疗失败的重要原因,正愈来愈受到研究者广泛重视。本文就冠渗漏引起根管治疗失败,冠渗漏与根尖渗漏的关系、冠渗漏的影响因素和预防措施等方面的研究现状作一综述。     

根管系统封闭性的影响因素及其检测方法

根管治疗术是牙髓病和根尖周病常见的治疗方法,术后严密封闭根管系统可以切断根尖周组织再感染途径,确保根管治疗的远期疗效。如果根管封闭性欠佳则容易引起病原微生物及其代谢产物经过封闭材料与根管壁之间的微渗漏(包括冠方和根尖区)使根尖周组织再感染导致根管治疗失败。可见严密封闭根管系统至关重要。目前检测根管封闭性的方法较多,但关于根管系统封闭性的影响因素和检测根管封闭性的方法尚缺乏较系统的阐述。本文将影响根管封闭性的因素及检测和评价根管封闭性的方法进行综述,为检测根管充填质量和评估远期疗效提供借鉴和参考。     

根管治疗牙冠方渗漏的研究现状

根管治疗是目前治疗牙髓病和根尖周病最有效和最根本的方法，评价其成败的关键因素是根管系统的三维严密充填，而根管充填后存在的微渗漏是导致充填失败的重要原因。根管微渗漏包括冠方渗漏和根尖渗漏，它们均可导致细菌及其产物通过冠方渗漏进入牙髓腔，又经根尖渗漏再次进入根尖周组织，引起治疗的失败。一直以来，根尖渗漏是研究的重点，而近年来，冠方渗漏也愈来愈引起广大学者的注意。本文从研究冠方渗漏的重要性、冠方渗漏的影响因素、冠方渗漏的体外实验及冠方渗漏与根尖渗漏的关系等几方面入手，对根管治疗牙冠方渗漏的研究状况作一综述。     

根管治疗后冠部封闭材料的渗漏研究

目的:为临床上根管治疗后采用不同的冠部充填或暂时封闭材料的封闭性能提供理论依据。方法:对常规根管治疗后的80个离体牙分别采用磷酸锌黏固粉(锌封)、锌基 复合体、锌基 银汞合金3种材料充填后进行染料渗漏实验,比较冠渗漏情况。结果:所有的实验组都发生了不同程度的渗漏,经统计学分析,显示对照组和各实验组之间、锌封组与其它两实验组之间的冠渗漏均存在显著性差异;而锌基 复合体组、锌基 银汞合金组之间的差异无显著性。结论:对于根管治疗后不能及时进行冠修复的牙齿应采用永久充填的方法来进行暂时性的冠部封闭,以减少冠渗漏的发生,提高根管治疗的远期成功率;对于临床上冠部充填体损坏时间过长(超过1月)需重新做牙体修复的患牙,建议考虑重新根管治疗或髓腔消毒后再行牙体修复。     

不同根管预备器械对根管充填后冠方微渗漏影响的实验研究

目的:比较不同根管预备器械对根管充填后冠方微渗漏的影响。方法:选择60个单根管前磨牙(弯曲度为10～20°)随机分为6组,分别以不锈钢K锉、VDW K锉、手动Protaper、机用Protaper、Hero642、Mtwo预备根管。采用冷侧压法进行根管充填,染色法比较不同根管预备器械对根管冠方封闭性能的影响。结果:不同根管预备器械对充填后根管冠方微渗漏影响不同,其中Hero 642预备组、Protaper预备组、VDWK锉组冠渗漏长度少于不锈钢K锉组,且差异有统计学意义(P<0.05),Hero 642预备组产生的冠方微渗漏最小。结论:不同根管预备器械预备根管后对冠渗漏影响不同,镍钛旋转器械预备根管后产生的冠方微渗漏较小,不锈钢K锉根管预备后产生的冠方微渗漏较大。     

牙体充填材料和根管桩对根管冠向封闭能力的影响

目的 :研究临床常用牙体充填材料和根管桩对根管冠向封闭能力的影响。方法 :6 0个离体单根管牙从颈部截断 ,逐步后退法预备根管 ,CCQ糊剂加牙胶尖侧压法充填 ,横断面统一制备 3mm× 2mm× 2mm洞形。随机分为 4组 :复合树脂组、银汞合金组、根管桩组、对照组 (不作洞形充填 )。经冷热循环 ,牙体表面封闭后行染液渗漏 ,制备透明牙标本 ,体视显微镜观察渗漏深度。结果 :各组实验牙均发生不同程度的染液渗漏 :复合树脂组 ( 3.35± 2 .0 1)mm和银汞合金组 ( 3.6 7± 1.4 0 )mm渗漏深度最短 ,两者无显著性差异(P >0 .0 5 ) ;根管桩组 ( 6 .0 0± 2 .13)mm渗漏深度长于前两组 (P <0 .0 5 ) ;对照组 ( 10 .4 7± 3.6 9)mm渗漏深度最长 ,与其他各组均有显著性差异 (P <0 .0 1)。结论 :复合树脂和银汞合金在根充后冠向封闭能力无明显差异 ;根管桩的使用会加大微渗漏程度     

根管细菌渗漏体外模型的建立

目的：建立检测微细菌培养模型，以用于评价根管充填封闭情况。方法：牙根的冠根两端各连接一细菌培养储室，冠方储室置1mL无菌培养基并接种0．1mL菌液，根方储室起始为无菌培养基。每隔3d将冠方储室中菌液吸出1mL，并注入1mL新鲜BHI培养基，共90d。当根尖储室中培养基发生浑浊即为细菌渗漏发生，记录细菌渗漏发生时的天数。选择18个直根管前牙，其中牙胶充填组6个，用冷牙胶侧方加压充填技术充填；空管组6个，根管只预备不充填；根管密封组6个，根管充填并严密封闭根管口和根尖孔。用设计的模型检测密封状况。结果：全部空管组6个样本在1d内根方储室中出现浑浊；根管密封组6个样本的根方储室在90d内均未发生浑浊。牙胶充填组有2个样本分别在44d和46d发生浑浊。结论：此模型方法简单易行且实用有效，具有一定的临床相关性和可行性。     

根管充填后冠方渗漏的体外实验

冠方渗漏是根管治疗失败的主要原因之一，体外实验是评价冠方渗漏的常用方法，主要有：放射性核素渗漏实验、染料渗漏实验和微生物渗漏实验。本文就这些方法作一综述。     

老年人根管治疗疗效相关因素分析

目的 研究老年人根管治疗疗效及其影响因素。方法 对56例65岁以上老年人在根管治疗后2年以上的126颗牙齿进行检查，按治疗年限分三组，2～3年组，4～5年组以及6年以上组，应用根尖周指数(Periapical-index)评定X线片并综合临床检查，对其疗效进行评价。结果 老年人根管治疗成功率为72．2％；三组间根管治疗成功率无显著性差异。恰填根管治疗的成功率(82.2％)比欠填和超填的的成功率(47．2%)要高；恰填病例中，冠方修复体质量好的患牙比质量差的患牙根尖周炎发病率低(25．7％和58.4％)；去除欠填和超填病例后，桩冠修复患牙的根管治疗成功率为58.8％，而未做桩冠修复的患牙成功率为87．5％。结论 根充质量、冠方修复体质量、桩冠修复是影响老年人根管治疗疗效的主要因素。     

不同根管预备方法对直根管即刻桩腔预备根尖封闭性影响的研究

目的观察直根管不同根管预备方法根管充填后即刻桩腔预备对根尖封闭性的影响。方法离体直单根管上前牙84个,其中80个按根管预备方法随机平均分为2组(n=40),A组:不锈钢根管锉常规法;B组:G型钻根管冠部预处理+不锈钢根管锉常规法,其余4个随机平均分配为阴性对照组和阳性对照组。所有根管均用侧方加压法充填,即刻垂直加压器去除部分充填材料,然后P型钻桩腔预备。用染料渗透法评价各组根尖封闭能力。结果B组的根管进行即刻桩腔预备后,其根尖微渗漏较A组轻(P<0.05)。结论大锥度根管预备,根管充填后即刻桩腔预备根尖封闭性较好。     

根管冠部预处理和不同锥度牙胶尖对根管充填后根尖部封闭性能的影响

目的:比较根管冠部预处理和不同锥度牙胶尖根管充填后的根尖封闭能力。方法:离体单根管恒牙42个,随机分为4组,用染料渗透法和透明标本法,测量根尖微渗漏距离,评价各组根尖封闭能力。结果:GG钻预处理和0.02锥度牙胶尖组根尖封闭能力最好;不用GG钻预处理和0.04锥度牙胶尖组根尖封闭能力最差。结论:根管预备时进行中上段的预处理,有利于增强根管充填后根尖段的封闭能力;用大锥度牙胶根管充填时应充分敞开根管中上段,否则易影响根尖段的充填效果,造成微渗漏;根管预备时进行冠方预处理,侧方加压法根充时选用合适的小锥度牙胶尖能取得较好的根管充填效果,提高根尖封闭能力。     

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??In root canal treatment??the ultimate aim of root canal obturation is to adequately fill the root canal system in order to prevent oral pathogens from colonizing and re-infecting the root and periapical tissues. Therefore??apical sealing ability of root canal fillings is the important factor that determines the success or failure of root canal treatment. Although there are various methodologies reported in the current literature for assessing apical sealability??they are not standardized??which make it difficult to compare the results. In this review??we have introduced the common methods for assessing apical sealability and critically analyzed the advantages and disadvantages of various methodologies.      

根尖封闭性评估方法研究进展

根管治疗中,根管充填的最终目的是严密封闭根管系统,以防止口腔致病菌在根管及根尖周组织定植、再感染。因此,根管充填后根尖封闭性是决定根管治疗成功与否的关键因素。当前文献中用于评估根尖封闭性能的方法多种多样,但各方法的评价标准不统一,使得实验结果难以获得较好的可比性。文章介绍了评估根尖封闭性的常用方法并就各方法的优缺点做一分析。     

根管治疗术后冠渗漏的实验研究

目的:为临床上采用不同的根管充填材料提供理论依据。方法:分别用Vitapex(V组)、Cor tisomol(C组)和Sealiteultra(S组)作根管封闭剂进行根管充填,通过葡萄糖微渗漏试验检测冠渗漏情况,比较其封闭性能。结果:采用Sealiteultra做根管封闭剂时根管充填出现的冠渗漏时间较其他两组晚,微渗漏的量也明显低于其他两组。结论:Sealiteultra根管封闭性能较好,值得推荐;如果用Cortisomol和Vitapex作根管封闭剂进行根管充填,建议尽快进行窝洞或人工冠修复。     

即刻桩腔预备对三种根管预备方法预备的直根管根尖封闭性的影响

目的 研究三种不同根管预备方法根管预备、根管充填后即刺桩腔预备对直根管根尖封闭性的影响.方法 离体直单根管上前牙124个,其中120个随机平均分为3组(n=40),A组:不锈钢根管锉常规法;B组:G 型钻根管冠部预处理 不锈钢根管锉常规法;C组:手用Pr01raper镍钛根管锉冠向下法,刺余4个随机平均分为阴性对照组和阳性对照组.所有根管均用侧方加压法充填,即刻手持垂直加压器去除部分充填材料,然后P型钻桩腔预备.用染料渗透法评价各组根尖封闭能力.结果 B组G型钻根管冠部预处理 不锈钢根管锉常规法预备的根管和C组手用ProTaper镍钛根管锉冠向下法预备的根管即刻桩腔预备后,其根尖微渗漏较A组常规法预备的轻(P<0.05).结论 大锥度根管预备,根管充填后即刻桩腔预备的根尖封闭性较好.     

Sealing capacity in vitro of thermoplasticized gutta-percha with a solid core endodontic filling technique

Abstract— This study assessed the sealing capacity of two endodontic gutta-percha filling techniques. Thirty-four single-rooted fully developed teeth were endodontically accessed, instrumented and randomly divided into two experimental groups ( n =12) and two control groups ( n =5). In Group A, root canals were obturated using a solid core thermoplastic technique (Densfil), in Group B and Group C (negative control) canals were obturated with laterally condensed gutta-percha, and in Group D (positive control) canals were left un-obturated. AH-26 was used as the sealer. Two days later, the teeth were conventionally prepared for testing apical and coronal leakage, immersed in india ink for 5 days and subsequently cleared. The linear coronal and apical extent of dye penetration was measured under a light dissecting microscope. The mean apical leakage for Group A was 1.39 mm, and for Group B 2.76 mm, whereas the mean coronal leakage for Group A was 2.87 mm, and for Group B 4.03 mm. The differences between the groups were not statistically significant (P>0.05).     

桩腔预备对根尖封闭性的影响及检测方法的研究进展

桩核冠修复是临床大面积牙体缺损的主要修复方法,桩腔预备是修复的第一步,预备过程中保持剩余根管充填物的完整性对于根尖封闭有重要意义.目前的研究表明:桩腔预备对根尖封闭性的影响与桩腔预备时机、剩余根管充填物长度和桩腔预备技术等有关.微渗漏量作为评价根尖封闭效果的重要指标,检测方法种类繁多,包括染色法、流体滤过(传输)系统、...     

The effect of smear layer on microbial coronal leakage of gutta-percha root fillings

The aim of this in vitro study was to determine the effect of removal of the smear layer on canal obturation as measured by penetration of bacteria from a coronal direction. One hundred and twenty extracted human teeth with straight, single root canals were decoronated. The canals were prepared using the modified double-flared technique with balanced force under copious irrigation. The apical matrix was prepared to size 40 and apical patency subsequently confirmed with a size 15 file. The teeth were divided randomly into experimental groups (80 teeth) and control groups (40 teeth). The root canals of 40 experimental and 20 control teeth were rinsed with 40% citric acid and 2% NaOCl to remove the smear layer before obturation. In experimental groups, 20 teeth with smear layer intact and 20 teeth with smear layer removed were obturated with lateral condensation of cold gutta-percha and Apexit sealer. A further 20 teeth with smear layer intact and 20 teeth with smear layer removed were obturated with the Trifecta technique with the same sealer. In control groups, 10 teeth with smear layer intact and 10 teeth with smear layer removed were obturated with lateral condensation of cold gutta-percha and Apexit sealer. These teeth were completely sealed both coronally and apically to serve as negative controls. The remaining 20 teeth with either smear layer intact or smear layer removed were not obturated and served as the positive controls. The root surface of each tooth was sealed with nail varnish. The cut end of a polypropylene tube was sealed around the coronal part of each root canal so that bacteria placed therein could move only through the obturated canal space. Each root was placed in a glass bottle containing sterile Todd-Hewitt Broth (THB) and aliquots of 0.5 ml of THB were injected into the polypropylene tube. The model system was centrifuged at 168 g. An innoculum of Streptococcus sanguis in THB was placed in each coronal chamber at 5-day intervals and daily observations were made for bacterial growth in the apical reservoir for 90 days. All positive control teeth showed bacterial penetration within 24 h, while the negative control teeth remained uncon-taminated throughout the test period. Leakage through the experimental teeth was variable ranging from 7 to 86 days. There was no statistical significant difference (P > 0.05) in leakage between the obturated canal when the smear layer was either removed or intact.