Model system parameters influence the sodium hypochlorite susceptibility of endodontic biofilms.

The parameters biofilm age, biofilm composition and substrate had a significant influence on the NaOCl susceptibility of E. faecalis biofilms. Older biofilms, multispecies biofilms and biofilms grown on dentine and hydroxyapatite had reduced NaOCl susceptibility. These findings emphasize the importance of selecting relevant parameters when designing a laboratory biofilm model system for the evaluation of antimicrobial treatments.