Antibiofilm Efficacy of Silver Nanoparticles Alone or Mixed with Calcium Hydroxide as Intracanal Medicaments: An Ex-Vivo Analysis

Abstract

Introduction: This study aimed to determine the most effective antibiofilm concentration of silver nanoparticles (AgNPs) alone or in combination with calcium hydroxide (Ca[OH]2) against Fusobacterium nucleatum biofilm. Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs alone or with Ca(OH)2 were determined. Dentin slices were sterilized and inoculated with F. nucleatum for 3 weeks to establish a biofilm. Samples were randomly assigned to determine the MIC and MBC for AgNPs alone or mixed with Ca(OH)2. A higher concentration of AgNPs for both preparations was also used. Triple antibiotic paste, Ca(OH)2, and saline were used as controls. Specimens in each group were subdivided over 2 observation periods: 7 and 14 days. At the end of each period, specimens were analyzed with 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) to determine the metabolic activity. Also, samples from each group were assessed by scanning electron microscopy. Results: The MIC and MBC of AgNPs alone against F. nucleatum coincided at 0.04%. The combination of AgNPs + Ca(OH)2 exhibited a lower MIC and MBC of 0.03%. MTT analysis showed a significant reduction in bacterial viability in all groups compared with negative controls (P < .05). A more substantial reduction in bacterial cells was observed with increasing concentrations of AgNPs at both periods. The combination (AgNPs [0.06%] + Ca[OH]2) was the most potent against F. nucleatum. Conclusions: The findings demonstrated that combining AgNPs with Ca(OH)2 was more effective on the F. nucleatum biofilm than either material alone, suggesting a combined effect.