Er:YAG激光对根管内粪肠球菌杀灭效果的观察研究

Bactericidal effect of Er:YAG laser radiation on Enterococcus faecalis in experimentally infected root canals

目的:观察Er:YAG激光对根管内粪肠球菌的杀灭效果。方法:收集单直根管人离体牙130个,根管预备并高压灭菌后,接种粪肠球菌并孵育4周。将样本随机分成4组,A组:采用Er:YAG激光+52.5 g/L次氯酸钠+生理盐水+蒸馏水处理;B组:Er:YAG激光+生理盐水+蒸馏水处理;C组:52.5 g/L次氯酸钠液处理;D组:生理盐水处理。然后,采集各组处理前后根管壁表面和牙本质小管不同深度处(0～100、100～200、200～300μm)试样进行细菌培养和计数,比较各处理组的细菌减少率。结果:A、B、C 3组在根管壁不同深度处的细菌减少率均显著高于生理盐水组(P<0.05),但其中只有A组根管壁表面、牙本质小管内100μm和200μm深度处的细菌减少率为100%。结论:Er:YAG激光+52.5 g/L次氯酸钠+生理盐水+蒸馏水组对根管内粪肠球菌的杀灭效果最好。

AIM： To evaluate the bactericidal effect of Er：YAG laser radiation on Enterococcus faecalis in experimentally infected root canals. METHODS： 130 extracted single-rooted human teeth with radiologically straight root canal were collected. After root canal preparation and sterilization, the root canals were inoculated with Enterococ- cus faecalis for 4 weeks. Then the were teeth randomly divided into 4 groups and received the treatment of Er ： YAG la- ser ＋ 52.5 g,/L sodium hypoehlorite （NaCIO） ＋ 9 g/L normal saline （NS） ＋ distilled water （ Er ： YAG/NaCIO）, Er： YAG laser ＋9 g/L NS ＋ distilled water （Er：YAG/NS）, 52.5 g/L NaCIO and 9 g/L NS（NaCIO）, respectively. The numbers of bacteria on the surface of root canal walls at different depths （0 -100, 100 ～200, 200 ～300 μm） inside dentinal tubules were counted before and after treatment, data were analyzed by one-way analysis of variance （ one-way ANOVA）. RESULTS： The bactericidal efficiencies of Er：YAG/NaC10, Er：YAG/NS and 52.5 g/L NaC10 were sig- nificantly higher than that of 9 g/L NS. However, only Er：YAG/NaCIO group showed no bacterial growth （bactericidal efficiency reached up to 100% ） on the surface of root canal walls and at the depth of 100～ 200μm inside the dentinal tubules. CONCLUSION： Er：YAG laser ＋ 52.5 g/L NaC10 ＋9 g/L NS ＋ distilled water may achieve strong bacte- ricidal effect on Enterococcusfaecalis .