Development of multifunctional dental adhesive with 4-formylphenyl acrylate and nano-silver.

OBJECTIVES: This study synthesized 4-formylphenyl acrylate (FA), capable of chemically binding to dentin collagen, and incorporated in-situ-synthesized antibacterial silver nanoparticles (NAg) to develop an experimental adhesive. The aim was to evaluate its antibacterial efficacy, bonding performance, and inhibitory effects on MMPs, offering a novel strategy to enhance dentin bonding stability. MATERIALS AND METHODS: Silver nanoparticle dispersion was analyzed via scanning electron microscopy (SEM). Antibacterial activity was tested against Streptococcus mutans biofilm using MTT assay, colony forming units counting, live/dead staining, and SEM. Bonding performance was examined through micro-tensile bond strength tests (immediate and aged), failure mode analysis, and nanoleakage evaluation. Resin-dentin bonding interface was observed via SEM, and collagenase activity in the hybrid layer was quantified using in situ zymography. RESULTS: The FA-Ag adhesive group significantly inhibited the metabolic activity of S. mutans biofilm, reduced colony-forming units, improved micro-tensile bond strength, minimized nanoleakage, demonstrated well-formed bonding interface, and suppressed MMPs activity. CONCLUSIONS: The FA-Ag-modified adhesive exhibits potent antibacterial properties, enhanced bond strength, and suppressed MMPs activity, making it a promising candidate for durable resin-dentin adhesion. CLINICAL RELEVANCE: This FA-NAg adhesive system offers a multifunctional solution to enhance restoration longevity. It concurrently combats bacterial biofilm, strengthens dentin bonding, and inhibits enzymatic degradation, thereby addressing major causes of restoration failure such as secondary caries and interface deterioration.