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

Abstract

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 disinfection 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 1m L 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% chlorhexidine gel disinfection.The incidence rate of the ablation phenomenon was low. Key words: Bicuspid; Lasers; Chlorhexidine; Enterococcus faecalis