次氯酸钠溶液冲洗根管对粪肠球菌的作用研究

Effects of sodium hypochlorite as endodontic irrigation on Enterococcus faecalis

关键词:  次氯酸钠  粪肠球菌  根管冲洗  平板计数法

Key words:  sodium hypochlorite  Enterococcus faecalis  endodontic irrigation  plate count

摘要:

［目的］研究次氯酸钠溶液对根管内粪肠球菌的作用效果。［方法］将20个离体前磨牙的感染根管标本随机均分为两组，5.25%次氯酸钠溶液冲洗组（NaClO）和0.9%生理盐水冲洗组（NaCl）。在根管预备、冲洗后取样培养，分别检测24、48 h、1周时粪肠球菌的菌落数目。［结果］24、48 h，5.25% NaClO组粪肠球菌完全被杀灭，菌落计数为0 CFU mL^-1，NaCl组均数分别为1.2×10⁶ CFU mL^-1、1.7×10⁶ CFU mL^-1；1周时，5.25% NaClO组有极少量的粪肠球菌被检出，菌落计数为109 CFU mL^-1，而NaCl组均数为3.8×10⁶ CFU mL^-1，两组于3个时间点的差异均具有显著性意义（P<0.01）。［结论］5.25%次氯酸钠溶液冲洗根管能立即抑制粪肠球菌,但不能完全清除粪肠球菌。

Abstract:

［Objective］This experiment evaluates the efficacy of 5.25% sodium hypochlorite (NaClO) as endodontic irrigation solution against Enterococcus faecalis within root canals.［Methods］Roots inoculated with E faecalis were randomly and evenly divided into two groups, which underwent different root canal irrigation: 5.25% NaClO, 0.9% sterile saline solution(NaCl). Canals were sampled after instrumentation using sterile paper points, and then incubated at 37 ℃.The colony forming units (CFU) grown were counted at 24 h, 48 h and 1 week.［Results］At 24 hour, 48 hour, Enterococcus faecalis in 5.25% NaClO group were completely killed, and the colony forming units were 0 CFU mL^-1. The average colony forming units of the NaCl group were respectively 1.2×10⁶ CFU mL^-1, 1.7×10⁶ CFU mL^-1. At 1 week, few Enterococcus faecalis were detected. The average colony forming units of the 5.25% NaClO group was 109 CFU mL^-1and the NaCl group was 3.8×10⁶ CFU mL^-1. There were significant differences between the two tested groups at three different time spots (P< 0.01).［Conclusions］5.25% NaClO endodontic irrigation solution can immediately kill Enterococcus faecalis, but it can not clean up the Enterococcus faecalis completely. Sodium hypochlorite only can reduce the amount of the Enterococcus faecalis,and make it in bacteriostasis within a period of time.