Antibacterial resin infiltrants containing DMAHDM and NACP: Effects on antibacterial activity, cytotoxicity, and remineralization potential - an in vitro study.

OBJECTIVES

To evaluate the effects of incorporating the antibacterial monomer dimethylaminohexadecyl methacrylate (DMAHDM; 2.5% and 5% wt%) and amorphous calcium phosphate nanoparticles (NACP; 2 wt%) on the antibacterial activity, cytotoxicity, and remineralizing potential of experimental resin infiltrants.

METHODS

Experimental infiltrants were formulated as follows: pure experimental resin infiltrant (ERI), ERI + 2.5% DMAHDM, ERI + 5% DMAHDM, ERI + 2% NACP, ERI + 2.5% DMAHDM + 2% NACP, ERI + 5% DMAHDM + 2% NACP, and the commercial control Icon (DMG). Antibacterial activity was assessed by bioluminescence assay (n = 18), Live/Dead assay (n = 2), and scanning electron microscopy. Cytotoxicity to human gingival fibroblasts was evaluated by cell metabolism assays (n = 3) and cytokine profiling (Luminex, n = 2). Remineralizing potential was analyzed by Knoop microhardness in treated white spot lesions (n = 6). Data were analyzed using ANOVA or Kruskal-Wallis tests (p < 0.05).

RESULTS

DMAHDM-containing groups showed significantly reduced bacterial viability compared with controls (p < 0.05). Antibacterial efficacy did not differ between the 2.5% and 5% DMAHDM groups (p > 0.05). Groups containing 5% DMAHDM exhibited lower fibroblast viability than those with 2.5%. NACP incorporation did not enhance antibacterial activity or promote remineralization (p > 0.05).

SIGNIFICANCE: Within the limitations of this in vitro study, DMAHDM incorporation into the experimental resin infiltrants promoted significant antibacterial activity against Streptococcus mutans, while higher DMAHDM concentration was associated with increased cytotoxicity. Under the tested conditions, the incorporation of 2 wt% NACP did not promote a significant remineralizing potential.