Evaluation of biocompatibility, antimicrobial activity, and immunomodulatory effects of mineral trioxide aggregate modified with zeolite-clinoptilolite as a root-end filling material

This study aimed to evaluate the in vitro toxicity of commercially available mineral trioxide aggregate (MTA) and various MTA modified cement types on a human fibroblast cell line. Additionally, the antibacterial and immunomodulatory properties of the modified cements were investigated. Modification of MTA cement was prepared by adding (5 wt %) of natural zeolite (CEM1), zeolite modified with zirconium dioxide (CEM2) and zeolite modified with silver and zinc (CEM3) to the MTA powder component. The antimicrobial effects of the tested substances were evaluated using the disk diffusion method. The cytotoxic effect of cements was determined by the MTT assay on human fibroblasts (MRC-5). In addition, the concentrations of cytokines IL-1β, TNF-α, IFN-γ, IL-17, and IL-10 were measured using high-sensitivity ELISA tests. There was no significant difference in the cytotoxic effects of the commercial cements MTA, CEM1, and CEM2 when compared to the negative control group after 24 h of evaluation. However, after 72 h, CEM1 demonstrated a statistically significant improvement in cell viability compared to the negative control group. Our study demonstrated that all MTA modifications incorporating zeolite and/or other components exhibited a stronger antimicrobial effect compared to MTA cement alone. Combined application of CEM1 and ConA significantly reduced levels of proinflammatory cytokines IL-1β (p < 0.001), TNF-α (p < 0.05), IFN-γ (p < 0.05), and IL-17 (p < 0.05), while simultaneously increased the level of the anti-inflammatory cytokine IL-10 (< 0.001), compared to cells treated with ConA alone. Considering its biocompatibility, antibacterial, and anti-inflammatory properties, the incorporation of natural zeolite into MTA appears to be a promising strategy for developing a novel root-end filling material.