Rapid Removal of Enterococcus faecalis Biofilms Within Root Canals using High‐Frequency Pulsed Nonequilibrium Atmospheric Pressure Plasma Jets (N‐APPJ)

ABSTRACT Enterococcus faecalis biofilms cause persistent endodontic failures. This study evaluates high‐frequency (100 kHz) pulsed non‐equilibrium atmospheric pressure plasma jets (N‐APPJ) for root canal disinfection. Compared to 8 kHz, 100 kHz excitation lowers breakdown voltage and enhances reactive species (RONS) production through higher power deposition. In synthetic models, 100 kHz N‐APPJ achieved a 5.3 log 10 CFU reduction within 10 min, exhibiting 2.1 times higher early‐stage bactericidal efficiency than the 8 kHz control. Ex vivo human tooth assays confirmed this superiority, with 100 kHz treatment kill 2 logs higher than the 8 kHz baseline. These results identify average power deposition as the critical factor for efficacy, establishing high‐frequency N‐APPJ as a rapid, potent modality for advanced endodontic biofilm eradication.