【作者】 王倩倩； 高娟； 张成飞； 李成杰；

【Author】 WANG Qian-qian,GAO Juan, ZHANG Cheng-fei. LI Cheng-jie. (Special Department, Peking University School and Hospital of Stomatology. Beijing 100081, China)

【机构】 北京大学口腔医学院特诊科；

【摘要】 目的:利用离体牙体外实验研究评估Er,Cr:YSGG激光和Nd:YAG激光对于感染根管的杀菌效果。方法:选择60颗单根直根管的前牙或者前磨牙,釉牙本质界处截去牙冠,机械预备至40#K锉。高温高压灭菌后根管内接种粪肠球菌Enterococcus faecalis(ATCC 29212)悬浊液,厌氧培养21天,得到感染根管的模型。随机分为6组,实验组4组分别用Er,Cr:YSCG激光1W、 1．5W功率照射根管,Nd:YAG激光1W、1．5W功率照射根管;阳性对照组为2．5％次氯酸钠冲洗组;阴性对照组不予任何处理措施。激光照射和次氯酸钠冲洗前后分别用无菌生理盐水和无菌纸尖取样,接种于BHI培养基培养,计数菌落CFU／ml。SPSS10．0 统计软件Mann-Whitney U检验分析数据。结果:Er,Cr:YSGG激光1W照射根管可以杀灭根管内77％的粪肠球菌,1．5W可以杀灭根管内96％的粪肠球菌,两者之间无显著性差异(P>0．05);Nd:YAG激光1W可以杀灭根管内97％的粪肠球菌,1．5W可以杀灭 98％的粪肠球菌,两者之间无显著性差异(P>0．05),但是与Er,Cr:YSGG激光1W、1．5W组有显著性差异(P<0．05);次氯酸钠冲洗组根管内粪肠球菌均降低至零。结论:Er,Cr:YSGG激光和Nd:YAG激光均可以有效降低根管内粪肠球菌(Enterococcus faecalis)的数量,Nd:YAG激光效果更好。更多还原

【Abstract】 PURPOSE: The aim of this study is to evaluate the bactericidal effect of the Er,Cr:YSGG laser and the Nd:YAG laser under standardized conditions, compared with NaClO irrigation in experimental infected root canals. METHODS: Sixty human single-rooted teeth with straight canals were selected. After preparation and sterilization. the specimens were inoculated with Enterococcus faecalis (ATCC 29212) and incubated for 21 days. The specimens were randomly divided into six groups, five experimental groups and a negative control group. The source of lasers were an Er,Cr:YSGG laser system emitting at a wavelength of 2,780nm (20HZ, 1W, 1.5W) and a Nd:YAG laser system emitting at a wavelength of l,064nm (15HZ, 1W, 1.5W). The irrigation was 2.5% NaOCl solution. After lasers irradiation or irrigation, the number of bacteria in each root canal was sampled with sterile physiological saline solution and paper points and then examined by counting the colony forming units on BHI agar plates. Statistical analysis was performed with statistics package (SPSS for windows, Release 10.0). The Mann-Whitney U test was used for group comparison at a level of 5%. RESULTS: The number of the E. faecalis was significantly reduced in each experimental groups. In cases of the Er,Cr:YSGG laser, the number of the E. faecalis was reduced 77% after irradiation at 1W and 96% at 1.5W, but there was no significantly difference (P>0.05). In cases of the Nd:Y AG laser. The number of the E. faecalis reduced 97% after irradiation at 1W and 98% at 1.5W and there was no significantly difference (P>0.05). Compared with the Er,Cr:YSGG laser, the Nd:YAG laser is more effective in reduction of the E. faecalis (P<0.05). After irrigated with 2.5% NaOCl solution, there was no bacteria colony detected on all the BHI agar plates. CONCLUSION: Both the Er,Cr:YSGG laser and the Nd:YAG laser have significantly bactericidal effect in infected root canals, and the Nd:YAG laser is more effective than the Er,Cr:YSGG laser.更多还原