Er∶YAG激光对根管内粪肠球菌和玷污层的清理效果

摘要

目的:研究Er∶YAG激光对根管内粪肠球菌和玷污层的清理效果.方法:将人离体单根管牙灭菌后接种粪肠球菌,随机分为2组:一组机械预备时联合生理盐水冲洗;另一组机械预备时联合NaClO冲洗.预备后两组再各自分为3个亚组:两组分别直接取样;两组分别经Er∶YAG激光照射后取样;两组分别经Ca(OH)2封药7d后取样.比较各组处理前后细菌减少率,以扫描电镜观察处理后各组根管内表面及牙本质小管.结果:Er∶YAG激光处理组细菌减少率高于仅NaClO冲洗、Ca(OH)2封药组(P＜0.05);但激光照射组使用生理盐水或NaClO冲洗杀菌率比较差异无统计学意义(P＞0.05).激光照射处理后根管内表面玷污层明显减少,牙本质小管口开放.结论:在根管机械预备后,使用Er∶YAG激光照射对根管的清理效果优于仅使用NaClO冲洗和Ca(OH)2封药,且清理效果与照射时使用的冲洗剂无关.提示Er∶YAG激光可单独应用于根管内消毒.%Objective:To evaluate the cleaning ability of Er∶YAG laser against Enterococcus faecalis in root canals.Methods:The single-rooted human teeth were sterilized and inoculated with Enterococcusfaecalis and were randomly assigned into 2 groups.A group of teeth was irrigated with saline during root canal preparation while another group with NaClO.After mechanical preparation,the two groups were randomly divided into 3 subgroups according to the different treatments:Samples,laser radiation,and calcium hydroxide intracanal medication for 7 days.Bactericical effects were compared among groups.Root canal walls and dental tubules were observed under scanning electron microscope.Results:Er∶YAG laser was the most efficient way for anti-bacteria among the groups (P＜0.05),but there was no significant difference between the 2 laser groups (P＞0.05).Meanwhile the smear laser was efficiently removed by laser compared with other treatments,and the laser could open the dentinal tubules.Conclusion:Er∶YAG laser can be effectively used for root canal disinfection without NaClO and Ca(OH)2.