Antibiofilm efficiency of silver and copper nanoparticle incorporated calcium hydroxide as an intracanal medicament: An in vitro study

Background and objectives: Silver (Ag) and Copper (Cu) Nanoparticles (NP) are a potential substitute for disinfection during endodontic therapy because of their antibacterial action against an array of pathogens, including resistant strains. This study aimed to assess the antibiofilm efficiency of calcium hydroxide modified with Ag and Cu NP suspension against E. faecalis, using confocal laser scanning microscopy (CLSM) and colony forming units (CFU) analysis. Methods: Dentine blocks were inoculated with Enterococcus faecalis for one week and 1 week-old biofilm of E. feacalis were randomly divided into 4 groups, control, calcium hydroxide, calcium hydroxide +2 % Cu NP and calcium hydroxide +2 % Ag NP. Following the incubation of the specimens with the medicament for 24 h at 37C, CLSM was used to evaluate the reduction in biovolume of the biofilm and the CFU was determined to assess the antimicrobial action of the NP-modified calcium hydroxide. Results: CLSM images revealed a significant reduction in the thickness of biofilm in both Ag and Cu groups compared to calcium hydroxide alone. The CFU results showed that group 4 and group 3 showed significantly less CFU followed by group 2 and group 1 (p < 0.001). Conclusion: Adding Cu and Ag NP to calcium hydroxide intracanal medication significantly increases its antibacterial activity against E. faecalis.