Chailertvanitkul P, Saunders W P, Saunders E M, MacKenzie D
Faculty of Dentistry, Khon Kaen University, Thailand.
Int Endod J. 1998 Sep;31(5):348-53. doi: 10.1046/j.1365-2591.1998.00164.x.
The aim of this study was to compose in vitro coronal leakage of a super EBA root-end filling material after two root-end cavity preparation techniques. A mixed anaerobic microbial marker was used. Forty-five extracted human teeth with straight, single root canals were prepared chemo-mechanically to a size 40 master apical file. The teeth were divided into experimental groups (35 teeth) and control groups (10 teeth). Forty teeth (35 experimental teeth and five negative control teeth) were obturated by lateral condensation of cold gutta-percha with Tubliseal EWT sealer. The remaining five teeth were not obturated and served as positive controls. These teeth were stored for 6 months in artificial saliva. The apical 3-4 mm of each root was resected perpendicular to the long axis of the root and a root-end cavity prepared to a depth of 3 mm using either a size 008 rosehead burr or an ultrasonic retroprep tip. Freshly mixed EBA cement was placed into the root-end cavity. The entire root surface of each tooth, except the cutting surface of the apical end, was sealed with nail varnish. The coronal part of each root canal was sealed with the cut end of a tube and placed in a bottle containing sterile Brain Heart Infusion Broth (BHIB). A marker consisting of Anaerobic streptococci and Fusobacterium nucleatum in BHIB was placed in each coronal chamber at 7-day intervals and daily observations were made for bacterial growth in the apical chamber for 60 days. All positive control teeth exhibited bacterial leakage within 48 h, whilst the apical chamber of negative control teeth remained uncontaminated throughout the test period. Fifty-nine percent (n = 10) of the specimens prepared with a burr showed leakage after 90 days, whilst only 22% (n = 4) of the ultrasonically prepared group showed leakage after the same time. The group prepared with ultrasonic tips showed statistically significant less specimens with leakage (P < 0.05) than the group prepared with burrs.
本研究的目的是比较两种根尖预备技术后，超EBA根尖充填材料的体外冠方微渗漏情况。使用了一种混合厌氧微生物标记物。选取45颗具有直的单根管的离体人牙，经化学机械预备至40号主尖锉。将牙齿分为实验组（35颗牙）和对照组（10颗牙）。40颗牙（35颗实验牙和5颗阴性对照牙）采用冷牙胶侧方加压充填，使用Tubliseal EWT封闭剂。其余5颗牙未进行充填，作为阳性对照。这些牙齿在人工唾液中保存6个月。将每颗牙根的根尖3 - 4 mm垂直于牙根长轴切除，然后使用008号玫瑰头车针或超声倒预备头制备深度为3 mm的根尖腔。将新鲜调制的EBA水门汀放入根尖腔。每颗牙齿的整个根面，除根尖端部的切割面外，均用指甲油密封。每个根管的冠方用一段管子的断端密封，然后放入装有无菌脑心浸液肉汤（BHIB）的瓶子中。每隔7天将由BHIB中的厌氧链球菌和具核梭杆菌组成的标记物放入每个冠方腔室，并对根尖腔室中的细菌生长情况进行60天的每日观察。所有阳性对照牙在48小时内均出现细菌渗漏，而阴性对照牙的根尖腔室在整个测试期间均未被污染。用车针制备的标本中有59%（n = 10）在90天后出现渗漏，而超声制备组在相同时间后只有22%（n = 4）出现渗漏。与用车针制备的组相比，超声制备组出现渗漏的标本在统计学上显著更少（P < 0.05）。
