Er：Yag 激光系统照射联合2％双氯苯双胍己烷凝胶对单根管前磨牙粪肠球菌感染模型杀菌效果

Sterilization effect of Er：Yag laser irradiation combined with 2% chlorhexidine gel on single tube premolar Enterococcus faecalis infection model

目的：评价Er：Yag激光系统照射联合2％双氯苯双胍己烷（洗必泰）凝胶对单根管前磨牙粪肠球菌感染模型杀菌效果。方法选择200颗单根直根管的前磨牙，进行消毒处理后检验磨牙无细菌感染。向高压灭菌后的单根管内接种粪肠球菌Enterococcus faecalis（ATCC 29212）菌悬液10μL，然后在37度条件下培养2周制作单根管前磨牙粪肠球菌感染模型。将200颗感染前磨牙模型分成四组：对照组（ n＝50）、A组（n＝50）、B组（n＝50）和C组（n＝50）。对照组不做任何消毒处理，A组接受Er：Yag激光系统照射和2％洗必泰凝胶进行消毒，B组仅接受Er：Yag激光系统照射，C组仅接受2％洗必泰凝胶消毒。消毒后将前磨牙放入10 mL无菌水中，充分混匀，然后取1 mL液体进行10倍稀释，再取200μL涂布至BHI琼脂平皿，选择可计数的平皿进行菌落计数，并计算每组的平均菌落数。结果 A组菌落平均数为（10±3）个，显著高于B组菌落平均数的（48±6）个（t＝12．005，P＝0．000）、C组菌落平均数的（43±5）个（t＝19．277，P＝0．000）。 A组50例感染模型中仅2例出现明显消融现象。结论 Er：Yag激光系统照射和2％洗必泰凝胶进行消毒效果优于Er：Yag激光系统照射和2％洗必泰凝胶消毒。且消融现象副作用发生率低。

Objective To evaluate the sterilization effect of Er：Yag laser irradiation combined with 2%chlorhexidine gel on single tube premolar enterococcus faecalis infection model.Methods After disinfection test was performed without molars bacterial infection,200 single rooted premolar root canal were selected.10μL enterococcus faecalis（ ATCC 29212） bacterium suspension were inoculated into single intratracheal with high pressure sterilization and and then were cultured for 2 weeks.200 infected premolar model were divided into four groups：control group （n=50）,A group （n=50）,B group （n=50） and C group （n=50）.The control group did not receive any disinfec-tion treatment,group A received Er：Yag laser irradiation and 2%chlorhexidine gel disinfection,B group received only Er：Yag laser irradiation,the C group received only 2% chlorhexidine gel disinfection.After disinfection,premolars were put into 10mL sterile water,mixed thoroughly,and then 1mL liquid were taken and diluted by10 times.Then the 200μL dilutions lipuid were coated on BHI agar plate,and plate could be selected for counting colony count.Results The average number of colonies was（127 ±12） in the control group,average number of group A（10 ±3） and which was lower than that group C （48 ±6）（t=12.005,P=0.000） and group C （43 ±5） （t=19.277,P=0.000）. There were only 2 cases,which had obvious ablation phenomena in group A.Conclusion Disinfection effect of Er：Yag laser irradiation combined with 2%chlorhexidine gel is better than that of Er：Yag laser irradiation or 2% chlo-rhexidine gel disinfection.The incidence rate of the ablation phenomenon was low.