ABSTRACT
Objective:To evaluate the bactericidal effects of nano-silver against Enterococcus faecalis(E.faecalis) growing in multi-species biofilm.Methods:85 biofilms were established using MBECTM P&G Assay with E.faecalis together with Fusobacterium nucleatum and P.melaninogenica.Thereafter,10 specimens were used as the controls,75 were randomly divided into 3 groups(n=25),and treated with 0.1% nano-silver (12-15 nm) solution,0.1% nano-silver (100 nm) solution and 2% hypochlorite solution,respectively.Each sample was then separated into 2 different tubes.PMA was added to one of the tubes,and the other was left untreated.Then,DNA extraction and qPCR were performed.The cycle threshold(Ct) values between samples were compared by paired t test.Results:The Ct values of the samples treated with PMA were higher than that without PMA(P=0.000) in the group of 0.1% nano-silver solution(12-15 nm)was higher than that in the group of 0.1% nano-silver solution(100 nm)and 2% sodium hypochlorite solution.(P<0.05);the value in the group of 0.1% nano-silver solution(100 nm)was larger than that in 2% sodium hypochlorite solution(P<0.05).Conclusion:0.1% nano silver solution might have a strong bactericidal effect against against E.faecalis growing in multi-species biofilm.The bactericidal effect may be enhanced with the small size of silver particles.