Emami Raheleh, Khedmat Sedigheh, Pirmoazen Salma, Honardar Kiamars
Assistant Professor, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Semnan University of Medical Sciences, Semnan, Iran.
Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences; Iranian Center for Endodontic Research, Tehran, Iran.
J Dent (Tehran). 2015 Nov;12(11):841-5.
The aim of this study was to compare apical sealing ability of alpha and beta phases of gutta-percha by means of bacterial leakage model.
Fifty single-rooted human premolars were selected. The root canals were prepared with Mtwo rotary instruments up to apical #35.04. Forty teeth were randomly divided into two groups (n= 20). The root canals were obturated by alpha phase (G1) and beta phase (G2) of gutta-percha and AH26 sealer, respectively, with warm vertical compaction technique. Ten teeth served as positive (n=8) and negative (n=2) control groups. Then, the specimens were sterilized with ethylene oxide gas. Bacterial suspension of Enterococcus faecalis (E. faecalis) in 0.5 McFarland concentration was prepared. All teeth were mounted in plastic vial caps containing Muller Hinton broth and then exposed to bacterial suspension of E. faecalis every three days up to 31 days. The number of days required for the contamination of the entire root canals was recorded. The data were analyzed using Mann Whitney U test.
There were no significant differences in bacterial leakage between the G1 and G2 groups (P>0.05). Negative controls revealed no microbial leakage; whereas positive controls showed gross microbial leakage.
Despite better thermal conduction and adaptability of alpha phase of guttapercha, our study revealed no significant difference in bacterial leakage between alpha and beta phases of gutta-percha in warm vertical compaction.
本研究旨在通过细菌渗漏模型比较牙胶尖α相和β相的根尖封闭能力。
选取50颗单根人前磨牙。使用Mtwo旋转器械将根管预备至根尖#35.04。40颗牙齿随机分为两组(n = 20)。分别采用牙胶尖α相(G1组)和β相(G2组)及AH26封闭剂,通过热垂直加压技术进行根管充填。10颗牙齿作为阳性(n = 8)和阴性(n = 2)对照组。然后,将标本用环氧乙烷气体消毒。制备浓度为0.5麦氏单位的粪肠球菌细菌悬液。所有牙齿安装在含有Muller Hinton肉汤的塑料瓶盖中,然后每三天暴露于粪肠球菌细菌悬液中,直至31天。记录整个根管被污染所需的天数。数据采用Mann Whitney U检验进行分析。
G1组和G2组之间的细菌渗漏无显著差异(P>0.05)。阴性对照组未显示微生物渗漏;而阳性对照组显示明显的微生物渗漏。
尽管牙胶尖α相具有更好的热传导性和适应性,但我们的研究表明,在热垂直加压充填中,牙胶尖α相和β相之间的细菌渗漏无显著差异。