Synthesis, Characterisation and Antibacterial Activity of Reduced Graphene Oxide‐Cuprous Oxide Nanocomposite Against Dual Species Biofilms Using Clsm

ABSTRACT Root canal irrigants are essential for biofilm elimination, with sodium hypochlorite (NaOCl) as the current gold standard, though limited by cytotoxicity and poor dentine penetration. This study assessed the antibacterial efficacy of a reduced graphene oxide–cuprous oxide (rGO–Cu 2 O) nanocomposite against Enterococcus faecalis and Streptococcus mutans biofilms. Thirty decoronated premolars were prepared with Protaper Next X5, and biofilms were cultured for 21 days. The rGO–Cu 2 O nanocomposite, synthesised using an 808 nm laser‐assisted method and characterised by FE‐SEM, XRD and XPS, was compared with 2.5% NaOCl and saline. Antibacterial activity was evaluated through CFU counts and confocal laser scanning microscopy. rGO–Cu 2 O showed significantly greater bacterial reduction than saline, with superior efficacy to NaOCl against E. faecalis and comparable effects against S. mutans . CLSM confirmed disruption of mature biofilms, indicating its promise as a novel endodontic irrigant.