Antibiofilm effect of different concentrations of silver nanoparticles combined with calcium hydroxide against Enterococcus faecalis biofilm: An ex vivo study

Abstract This study aimed to evaluate the antibiofilm activity of different concentrations of silver nanoparticles (AgNPs) in combination with calcium hydroxide [Ca(OH) 2 ] against Enterococcus faecalis biofilm. On an E. faecalis biofilm on dentin discs, the following medicaments were applied for 7 days ( n = 13/group): 0.005% AgNPs+Ca(OH) 2 , 0.01% AgNPs+Ca(OH) 2 , 0.02% AgNPs + Ca(OH) 2 , Ca(OH) 2 and saline/control. Specimens were stained with LIVE/DEAD® Bac Light™ dye and analysed with confocal laser scanning microscopy. Proportion of dead bacteria was calculated and analysed. There was a significant reduction in E. faecalis biofilm in all medicament groups (43.5%, 49.1%, 69.1%, 48.7%) respectively, compared with control group (2.54%) ( p < 0.001). The 0.02% AgNPs + Ca(OH) 2 group demonstrated the most significantly superior antibiofilm effect, with no significant difference between remaining groups. In conclusion, combining 0.02% AgNPs enhanced the antibiofilm effect of Ca(OH) 2 on E. faecalis biofilm compared with lower AgNPs concentrations.