根管倒充填材料研究进展

从根管倒充填材料的微渗漏和边缘密合性、组织相容性、抗菌性能三个方面，对国内外学者关于各种根管倒充填材料研究方面的现况进行分析总结。     

3种临床常用根管充填材料体外微渗漏实验研究

根管充填材料密封性能的好坏直接关系到根管治疗的疗效.本实验采用染色法对比3种根管充填材料对离体人牙根管的密封性,为临床选用根管充填材料提供一定的试验依据.     

新型根管充填材料的研究进展

一个多世纪以来，根管充填的主要材料是牙胶，辅以氧化锌丁香油或氢氧化钙等传统根管封闭剂共同完成根管治疗。近年来，人们不断改良传统封闭剂，也研发出一些新的材料以求进一步提高根管治疗的效果。本文主要介绍了新型根管封闭剂（如多聚甲基硅烷类封闭剂RSA、树脂类封闭剂AHPlus）和充填材料Guttaflow的组成、生物相容性、封闭性、再处理性以及抗菌性等方面的特点，同时通过与新材料的比较也介绍了氧化锌丁香油或氢氧化钙等传统根管封闭剂的研究进展。     

根尖倒充填材料的研究进展

根尖倒充填术的目的是严密封闭根尖孔与根尖周组织的交通，预防根尖微渗漏，常用于非手术治疗失败，不能用常规方法进行根管治疔术且要尽量保留患牙的病例。由于大量材料已应用于根尖倒充填，本文对各种以往在临床和动物实验中常用的根尖倒充填材料作一简要综述。     

根管偏移对充填材料封闭根管能力的影响

目的 :研究弯曲根管预备后的根管偏移对充填材料封闭根管能力的影响。方法 :选取 73颗下颌单根管前磨牙作为研究对象 ,其中弯根管牙 46颗 ,直根管牙 2 7颗。A组 2 3颗弯根管牙用Lightspeed器械预备根管 ,B组 2 3颗弯根管牙、C组 17颗直根管牙以及对照组牙用K锉预备根管 ,预备方法为逐步后退技术。使用双曝光X线技术和Ehrlich法测量根管偏移指数 (ATI)的大小。使用侧向加压技术充填所有根管后 ,用流体传输模型测量每个根管内微渗漏的量。结果 :A组中有 19%的根管发生根管偏移 ,B组中有 85 %的根管发生根管偏移 ,两组之间ATI的大小有高度显著性差异。当ATI大于 0 .3mm时 ,根管内微渗漏的发生率明显增加。结论 :弯曲根管预备中出现的根管偏移会削弱充填材料封闭根管的效果。     

根管充填材料根尖微渗漏的评估方法研究进展

该文介绍了根尖微渗漏的几种评估方法,包括:染色法、电化学法、放射性同位素渗透法、液体滤过(传输)法和细菌或内毒素渗透法、CT扫描和计算法等。这些方法没有统一的标准,在比较使用这些方法而获得的结果时就较困难。?     

纳米根管充填材料根尖封闭能力的实验研究

目的 观察纳米材料根充后根尖微渗漏请况，评价其根尖封闭能力。方法 30颗离体单根管牙牙根，随机分为三组，每组10个，预备完成的根管用牙胶尖和一种根管糊荆、采用侧方加压法进行充填。根据染料在牙根中的渗入深度，评价根尖微渗漏情况。结果 三种材料的根尖微渗漏有显著差异（P〈0．01）；n-ZO组的根尖微渗漏最小，n-HA组次之，ZOE组最大。结论 纳米氧化锌糊剂和纳米羟磷灰石糊剂具有良好的根尖封闭性，可以作为根管封闭剞用于根管充填。     

根管偏移对充填材料封闭根管能力的影响

目的：研究弯曲根管预备后的根管偏移对充填材料封闭根管能力的影响。方法：选取73颗下颌单根管前磨牙作为研究对象,其中弯根管牙46颗,直根管牙27颗,A组23颗弯根管牙用Lightspeed器械预备根管,B组23颗弯根管牙,C组17颗直根管牙以及对照组牙用K锉预备根管,预备方法为逐步后退技术,使用双曝光X线技术和Ehrlich法测量根管偏移指数（AT1）的大小,使用侧向加压技术充填所有根管后,用流体传输模型测量每个根管内微渗漏的量,结果：A组中有19％的根管发生根管偏移,B组中有85％的根管发生根管偏移,两组之间AI1的大小有高度显著性差异,当ATI大于0．3nm,时,根管内微渗漏的发生率明显增加,结论：弯曲根管顶备中出现的根管偏移会削弱充填材料封闭根管的效果。     

根管三维充填的研究进展

严密充填根管、侧支根管及根管不规则区是彻底消除死腔和防止再感染的关键，而良好的根管清理和根管成形又是实现根管三维充填的重要前提。目前多种根管充填技术在不同程度上实现了对根管的三维严密充填。对根管三维充填的研究具有重要的临床意义。     

两种根管充填材料在根管桩根管制备前后微渗漏比较

目的:通过根管桩根管制备前后微渗漏试验比较两种不同根管充填材料的根尖封闭性能。方法:将40颗新鲜拔除的人的单根管牙,在釉牙骨质界处切除牙冠。随机分为2组,A组20颗牙,根管制备后根充糊剂 牙胶尖充填,7d后10颗牙齿行桩的制备为A1组,10颗牙留作对照为A2组。B组20颗牙根管制备后Ther-mafil热熔牙胶充填,7d后,10颗牙行桩的根管制备为B1组,10颗牙留作对照为B2组。全部牙1%亚甲基蓝溶液染色72h,将牙体纵劈,观察根尖部染料的渗漏情况,并进行统计分析。结果:各组的平均染色长度分别为A1组4.37±0.46mm,A2组2.67±0.24mm,B1组2.69±0.24mm,B2组1.06±0.21mm。A1组和A2组相比统计学上差异有显著性(P<0.05),B1组和B2组相比统计学上差异有显著性(P<0.05)。结论:桩的根管制备降低根管充填材料的根尖封闭性。     

Effects of new adhesive resin root canal filling materials on vertical root fractures

The aim of this study was to compare the fracture resistance of roots following root canal therapy using the RC Sealer system, the Epiphany system and the conventional system of gutta-percha and Sealapex. Fifty-six maxillary central incisors were divided into eight groups of seven teeth each, according to master apical file size and obturation systems. Obturation materials in the root canal were vertically loaded using a universal testing machine. Fracture loads were analysed by anova and Tukey comparison, and fracture patterns were analysed with ordinal logistic regression. Master apical file size 80 had a significantly lower fracture load than size 40 (P < 0.05). The groups obturated using the Resilon Cone and the Epiphany Sealer had significantly lower fracture loads than the other groups (P < 0.05). There was no significant improvement in resistance to vertical root fractures using the examined adhesive resin root canal filling systems, compared with conventional gutta-percha and sealer.     

Biocompatibility of various root canal filling materials ex vivo

Aim  To evaluate the biocompatibility of a resin-based endodontic filler (RealSeal) using the indirect cytotoxicity test.
Methodology  Human gingival fibroblasts were cultured ex vivo . Pellets of the materials to be tested were incubated for 24, 48, and 72 h at 37 °C under sterile conditions to obtain their eluates. The fibroblasts were exposed to either diluted (50%) or undiluted eluates for 24 h. A culture medium with foetal calf serum was added to the control wells. Cell viability was estimated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide method. The data concerning cell viability were statistically analyzed using one-way anova test and Bonferroni multiple comparisons test.
Results  Eluates obtained after 24 h of incubation with the resin filler did not reduce cellular viability. An increase in cellular viability, as compared with control cells, was observed in the gutta-percha group. The undiluted eluate from the polyether material was cytotoxic, causing an 82 ± 4% decrease in cellular viability. Eluates obtained after 48 h of incubation with the resin filler increased cellular viability, whereas the polyether significantly reduced viability. Gutta-percha did not cause any detectable change. After 72 h of incubation the eluate of the resin filler caused an increase in cellular viability, as did gutta-percha, whereas polyether caused a significant decrease.
Conclusions  RealSeal resin filler was nontoxic in this laboratory model. Further investigations are necessary to verify its usefulness in clinical applications.     

生物根管封闭剂iRoot SP在根管根尖封闭中的应用评价

目的:分析生物根管封闭剂iRoot SP在扁形根管根尖封闭中的性能,为临床工作提供指导.方法:取48颗根管的近远中径与颊舌径之比小于0.5的单根管离体前磨牙,根管预备后,随机分为A、B、C3组,每组各16颗.分别选用Vitapex (A组)、AH Plus(B组)、iRoot SP(C组)作为根管封闭剂,结合连续波热牙胶垂直充填技术进行根管充填.所有样本经根尖染料渗透实验,采用透明牙技术,比较3组离体牙微渗漏情况,评价iRoot SP在扁形根管根尖封闭中的性能.采用SPSS19.0软件包对数据进行统计学分析.结果:A组染料渗入深度显著大于B、C组,差异具有显著性(P＜0.05);B、C组染料渗入深度相比,无显著差异(P＞0.05).结论:iRoot SP和AH Plus在扁形形根管根尖封闭中的性能接近,效果优于Vitapex根管充填糊剂.     

Biocompatibility of retrograde root filling materials: a review

The aim of a retrograde filling material is to fill the apical canal space and to obtain a hermetic seal between the periodontium and the root canal system. Several materials have been suggested for root-end filling including: amalgam, gutta-percha, zinc oxide-eugenol cements, glass ionomer cement, gold foil pellets, Cavit, composite resin and mineral trioxide aggregate (MTA). Super-ethoxy benzoic acid and MTA are the most suitable materials and provide better results in apicoectomy procedures than other filling materials. Unfortunately, the ideal material for this purpose has yet to be found. This article is a review of the biocompatibility of retrograde filling materials.     

Biocompatibility of root canal filling materials

Results of in vitro and in vivo studies clearly indicate that some endodontic sealers may cause local and systemic adverse effects. Though occasionally contradictory data has been reported from various authors, it may be concluded that zinc-oxide-eugenol sealers possess a marked cytotoxic and tissue-irritating potency. Most Ca(OH)2-based materials, however, were biocompatible. Genotoxic effects have been observed with sealers releasing paraformaldehyde or containing mutagenic substances, such as bisphenol-A-diglycidyl-ether or its derivatives. It cannot be excluded that these materials may pose a systemic risk because formaldehyde is rapidly distributed systemically following its application into the pulp cavity. Furthermore an increasing number of cases with an aspergillosis of the maxillary sinus have been observed which were mainly caused by zinc-releasing endodontic sealers. Overall, it is recommended that for endodontic practice, sealers that have been found to be biocompatible in a "mixed bag" of various in vitro and in vivo tests, be selected. From this point of view, ZnOE-sealers should no longer be used for root canal fillings. This recommendation applies also to sealers containing paraformaldehyde or generating this substance during their setting reaction. More experimental and clinical studies are necessary to elucidate whether new materials, such as mineral trioxide aggregate (MTA) or calcium phosphate cement, will be biocompatible alternatives in the future.