Enhancement of physical and antimicrobial properties of mineral trioxide aggregate (MTA) reinforced with gold nanoparticles: An in vitro preliminary study.

BACKGROUND: Clinical use of mineral trioxide aggregate (MTA) is often associated with several challenges, including a prolonged setting time, poor handling characteristics and compromised physical properties in the presence of tissue fluids. Mineral trioxide aggregate, when used as a perforation repair or root-end filling material, needs adequate strength to withstand the forces acting on it. Recently, several researchers have attempted to overcome these challenges through the use of various additives. OBJECTIVES: To evaluate the physical and antimicrobial properties of MTA reinforced with gold nanoparticles (AuNPs). MATERIAL AND METHODS: Sixteen customized putty molds (6 mm in height x 4 mm in diameter) were filled with the materials assigned to 2 groups: control group, MTA (n = 8); and experimental group, MTA + AuNPs (n = 8). Compressive strength (CS) was evaluated using a universal testing machine, while setting time was assessed using a flat-ended indenter. The antimicrobial properties of MTA and MTA + AuNPs were evaluated using the agar diffusion method against Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. The data was statistically analyzed using an unpaired t-test. RESULTS: Compressive strength was significantly higher in the MTA + AuNPs group (115.75 ±2.22 MPa) than in the MTA group (55.00 ±5.35 MPa) (p < 0.001). The MTA + AuNPs group also demonstrated a significantly shorter setting time than the MTA group (48.05 min vs. 165.00 min, respectively). The unpaired t-test revealed a significantly greater antimicrobial activity against all tested microorganisms in the MTA + AuNPs group than in the MTA group (P. aeruginosa > E. coli > S. aureus > E. faecalis > C. albicans). CONCLUSIONS: Incorporation of AuNPs into MTA enhanced CS, shortened setting time and increased antimicrobial activity against the tested microorganisms.