Comparative evaluation of novel endodontic substances: cytocompatibility, pulp tissue dissolution, biofilms disruption and modulation of pro-inflammatory cytokines

The objective of this study was to evaluate the biological properties of calcium hypochlorite [Ca(OCl)₂], octenidine dihydrochloride (OCT), Octenisept^® (OCTS), and N-acetylcysteine (NAC) compared to sodium hypochlorite (NaOCl). Cytocompatibility, pulp tissue dissolution, antimicrobial activity against mono- and dual-species biofilms (Enterococcus faecalis and/or Candida albicans), and antigenic potential with Escherichia coli LPS stimulus were assessed. Data was statically evaluated (α = 0.05). NaOCl was most cytotoxic, followed by Ca(OCl)₂. Among the novel substances, Ca(OCl)₂ was most effective against E. faecalis and dual-species biofilms, while NAC showed higher antibiofilm activity against C. albicans (crystal violet assay). All substances except NAC reduced E. faecalis (CFU mL^-1 log₁₀) in dual-species biofilms. NaOCl and Ca(OCl)₂ demonstrated the highest antibiofilm action, followed by OCT (confocal laser scanning microscopy). All solutions inhibited TNF-α gene expression at 12h (RT-qPCR). These novel substances were cytocompatible, exhibiting significant antimicrobial activity and anti-inflammatory potential.