Chailertvanitkul P, Saunders W P, MacKenzie D, Weetman D A
University of Glasgow Dental School, UK.
Int Endod J. 1996 Jul;29(4):249-55. doi: 10.1111/j.1365-2591.1996.tb01377.x.
The aim of this in vitro study was to investigate the coronal leakage of obligate anaerobes into root canals obturated with lateral condensation of cold gutta-percha with two root canal sealers. Sixty extracted human teeth with straight, single root canals were prepared using the modified double-flared technique with balanced force under copious irrigation until the master apical file was size 40. The teeth were divided randomly into experimental groups (40 teeth) and control groups (20 teeth). In the experimental groups, 20 teeth were obturated with lateral condensation of cold gutta-percha and AH26 sealer and 20 teeth were obturated with the same technique using TubliSeal EWT sealer. In the control groups, 10 teeth were obturated with the same technique either with AH26 or TubliSeal EWT sealer. These teeth were completely sealed to serve as negative controls. The remaining 10 teeth were not obturated and served as positive controls. The root surface of each tooth was sealed with nail varnish except the apical 2 mm. The coronal part of each root canal was sealed with the cut end of polypropylene tube and placed in a glass bottle containing sterile Fastidious Anaerobe Broth (FAB). Aliquots of 0.5 mL of FAB were injected into the polypropylene tube and the model system was centrifuged at 168 g. An inoculum of Fusobacterium nucleatum in FAB was placed in each coronal chamber at 7-day intervals and daily observations were made for bacterial growth in the apical reservoir for 12 weeks. All positive control teeth showed bacterial leakage within a week, while the negative control teeth remained uncontaminated throughout the test period. All the experimental teeth exhibited leakage of bacterial metabolites within 12 weeks, ranging from 1 to 12 weeks. The mean time for complete leakage in the AH26 and the TubliSeal EWT groups was 8.4 and 8.2 weeks respectively. There was no statistically significant difference (P > 0.05) in leakage between the AH26 and the TubliSeal EWT groups.
本体外研究的目的是调查专性厌氧菌通过两种根管封闭剂采用冷牙胶侧方加压充填法充填根管时的冠部微渗漏情况。使用改良双喇叭口技术在大量冲洗下采用平衡力法预备60颗拔除的具有直的单根管的人牙，直至主尖锉为40号。将牙齿随机分为实验组（40颗牙）和对照组（20颗牙）。在实验组中，20颗牙采用冷牙胶侧方加压法和AH26封闭剂充填，20颗牙采用相同技术使用TubliSeal EWT封闭剂充填。在对照组中，10颗牙采用相同技术分别用AH26或TubliSeal EWT封闭剂充填。这些牙齿完全封闭作为阴性对照。其余10颗牙未充填作为阳性对照。每颗牙齿的根面除根尖2mm外均用指甲油密封。每个根管的冠部用聚丙烯管的截断端密封，并置于装有无菌苛求厌氧菌肉汤（FAB）的玻璃瓶中。将0.5mL的FAB等分试样注入聚丙烯管中，模型系统以168g离心。每隔7天将FAB中的具核梭杆菌接种物置于每个冠部腔室中，并对根尖储液器中的细菌生长进行12周的每日观察。所有阳性对照牙在一周内均出现细菌渗漏，而阴性对照牙在整个试验期间均未被污染。所有实验组牙齿在12周内均出现细菌代谢产物渗漏，时间为1至12周。AH26组和TubliSeal EWT组完全渗漏的平均时间分别为8.4周和8.2周。AH26组和TubliSeal EWT组之间的渗漏情况无统计学显著差异（P>0.05）。
