常用口腔修复材料表面细菌黏附的实验研究

Adhesion of different bacterium to the surface of restorative materials in vitro

目的:分析冠修复初期口腔常见菌种在修复体表面黏附和定植的数量,为临床选择合适的修复体和尽可能减少细菌在修复体表面附着和定植提供参考。方法:将烤瓷、钴铬合金逐级打磨抛光后,与釉质一起放入分别含有变形链球菌(Ua)、内氏放线菌(An)和牙龈卟啉单胞菌(Pg)的混合培养基中作厌氧培养,在6h、12h和24h3个时间段,分别定量检测试件表面黏附的细菌数量以及液体培养基中的细菌数量,采用SPSS6.0软件包对结果进行F检验。结果:3种试件表面及液体培养基中均检测不到Pg,烤瓷组和釉质组黏附的细菌少于钴铬合金组。前6h,Ua/An在3组试件表面的附着相同;12h后,An在钴铬合金表面增加最快,烤瓷次之,釉质最慢;24h后,Ua在钴铬合金组表面最多,在烤瓷和釉质组表面的黏附情况相似,An在钴铬合金组表面增加最快,烤瓷组和釉质组的Ua/An几乎没有变化。结论:3种细菌混合培养时,Pg受到强烈的抑制。如要抑制Ua的附着和定植,对于钴铬合金修复体,前6h是关键期。而对于烤瓷修复体,前12h是关键期。如要抑制An的附着与定植,对于钴铬合金修复体,前24h是关键期,对于烤瓷修复体,前12h是关键期。烤瓷修复体优于钴铬合金修复体。

PURPOSE： Mutans（Ua）, porphynomonas（Pg）,actinomyces Naeslundii（An） are the 3 bacteria that may cause the clonal formation, gingivitis and periodontitis. The aim of this study was to observe adhesion on the surface of the dental restorative materials and enamel, and to analyze the sequence of these adhesions and offer now the options for the prevention of their occurrence. METHODS： The specimen made of PFM and Co-Cr alloy were polished step by step. Then, along with the enamel.they were put into the liquid BHI culture medium containing Ua, Pg and An. After 6 hours, 12 hours and 24 hours, the adhesive microbial amount in the culture medium were determined by counting formation unit. F test was used to analyze the results with SPSS6.0 software package. RESULTS： Pg was found neither on the surface of specimen, nor in the liquid BHI culture medium; The surface roughness （Ra） of PFM and enamel was bigger than that of Co-Cr alloy, but the number of adherent bacterium on them was smaller; The value of Ua/A n was almost the same among the 3 groups within 6 hours. Twelve hours later, the maximal increment of A n was seen in the group of Co-Cr alloy and the minimal increment in the group of enamel while 24 hours later, the largest number of Ua/A n was seen in the group Co-Cr alloy. There were no change in the groups of PFM and enamel during 12 and 24 hours. CONCLUSIONS： Pg is inhibited when these bacteria are cultivated together. To prevent the adhesion of Ua, the first 6 hours is the critical period for Co-Cr alloy, and the first 12 hours for PFM.To avoid the adhesion of An, the key period is the first 24 hors for Co-Cr alloy and the first 12 hours for PFM. Given the result of the analysis, we prefer PFM to Co-CR alloy. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality （Grant No. 08DZ2271100） and Shanghai Leading Academic Discipline Project （Grant No. T0202）.