Immediate and sustained killing effects of atmospheric-pressure plasma on young and mature biofilms of <i>Enterococcus faecalis</i>

The immediate killing effect of atmospheric-pressure plasma (APP) has been frequently investigated, but its sustained activity is poorly understood. goal the present study to evaluate both and effects APP on Enterococcus faecalis. jet was evaluated by optical emission spectroscopy (OES) laser-induced fluorescence (LIF). Hydroxyapatite (HA) discs coated with bovine dermal type I collagen were used as substrates for bacterial growth. After formation E. faecalis biofilms HA seven days or three weeks, samples treated (A) 2 ml saline, (B) APP, (C) 2% chlorhexidine digluconate (CHX) 5 min. then cultured days, after which they examined scanning electron microscopy confocal laser microscopy. OES results showed that typical reactive oxygen nitrogen species included in full spectrum. fitted curve indicated rotation temperature N2 close room temperature. LIF maximal O OH intensities occurred at mm from nozzle. For seven-day three-week biofilms, CHX treatments had significant sterilization (P < 0.05) compared saline group terms effects. demonstrated excellent potential use an alternative approach treatment periapical diseases.