Fischer E J, Arens D E, Miller C H
Indiana School of Dentistry, Indianapolis 46202, USA.
J Endod. 1998 Mar;24(3):176-9. doi: 10.1016/S0099-2399(98)80178-7.
Several dye leakage studies have demonstrated the fact that mineral trioxide aggregate (MTA) leaks significantly less than other root-end filling materials. The purpose of this study was to determine the time needed for Serratia marcescens to penetrate a 3 mm thickness of zinc-free amalgam, Intermediate Restorative Material (IRM), Super-EBA, and MTA when these materials were used as root-end filling materials. Fifty-six, single-rooted extracted human teeth were cleaned and shaped with a series of .04 Taper rotary instruments (Pro-series 29 files). Once the canals were prepared in a crown down approach, the ends were resected and 48 root-end cavities were ultrasonically prepared to a 3 mm depth. The teeth were then steam sterilized. Using an aseptic technique, under a laminar air flow hood, the root-end cavities were filled with amalgam, IRM, Super-EBA, and MTA. Four root-end cavities were filled with thermoplasticized gutta-percha without a root canal sealer and served as positive controls. Another four root-end cavities were filled with sticky wax covered with two layers of nail polish and served as negative controls. The teeth were attached to presterilized (ethylene oxide gas) plastic caps, and the root ends were placed into 12-ml vials of phenol red broth. Using a micropipette, a tenth of a milliliter of S. marcescens was placed into the root canal of each tooth. To test the sterility of the apparatus set-up, the root canals of two teeth with test root-end filling materials and one tooth from the positive and negative control groups were filled with sterile saline. The number of days required for S. marcescens to penetrate the four root-end filling materials and grow in the phenol red broth was recorded and analyzed. Most of the samples filled with zinc-free amalgam leaked bacteria in 10 to 63 days. IRM began leaking 28 to 91 days. Super-EBA began leaking 42 to 101 days. MTA did not begin leaking until day 49. At the end of the study, four of the MTA samples had not exhibited any leakage. Statistical analysis of the data indicated Mineral Trioxide Aggregate to be a most effective root-end filling material against penetration of S. marcescens.
多项染料渗漏研究已证实，三氧化矿物凝聚体（MTA）的渗漏量明显低于其他根充材料。本研究的目的是确定当使用无锌汞合金、中间修复材料（IRM）、超EBA和MTA作为根充材料时，粘质沙雷氏菌穿透3毫米厚的这些材料所需的时间。56颗单根拔除的人牙用一系列0.04锥度旋转器械（Pro - series 29锉）进行清理和预备。一旦根管采用冠向下法预备完成，根尖切除，48个根尖腔用超声预备至3毫米深度。然后对牙齿进行蒸汽灭菌。采用无菌技术，在层流通风橱下，根尖腔分别用汞合金、IRM、超EBA和MTA充填。4个根尖腔用未加根管封闭剂的热塑牙胶充填，作为阳性对照。另外4个根尖腔用涂有两层指甲油的粘性蜡充填，作为阴性对照。将牙齿固定在预先灭菌（环氧乙烷气体）的塑料帽上，根尖放入12毫升含酚红肉汤的小瓶中。用微量移液器向每颗牙齿的根管内注入十分之一毫升粘质沙雷氏菌。为检测仪器装置的无菌性，两颗使用试验性根充材料的牙齿以及阳性和阴性对照组各一颗牙齿的根管内充填无菌生理盐水。记录并分析粘质沙雷氏菌穿透四种根充材料并在酚红肉汤中生长所需的天数。大多数用无锌汞合金充填的样本在10至63天内细菌渗漏。IRM在28至91天开始渗漏。超EBA在42至101天开始渗漏。MTA直到第49天才开始渗漏。研究结束时，4个MTA样本未出现任何渗漏。数据的统计分析表明，三氧化矿物凝聚体是抵抗粘质沙雷氏菌穿透的最有效根充材料。
