Advanced Dental Composite Technology via Bisilanized Dual-Action Nanofillers for Biofilm Control

Achieving durable tooth restorations in the complex oral environment demands resin-based composites (RBCs) with long-lasting antibiofilm properties, superior mechanical performance, and biosafety. This study introduces a duomodal strategy to create functional nanofillers for advanced RBC formulations. Mesoporous silica nanoparticles are loaded with the antibacterial agent cetylpyridinium chloride (CPC) and bisilanized using the antibacterial dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DTSACl) along with 3-(trimethoxysilyl)propyl methacrylate. The resulting bisilanized nanofillers, S_CM, are incorporated into RBCs at various weight percentages (0-20 wt%). The 20 wt% S_CM-RBC formulation showcases exceptional antibiofilm capabilities against 14 oral species, including cariogenic, periopathogenic, and commensal bacteria, leveraging a dual antibacterial mechanism: CPC release and anchored DTSACl action. Additionally, S_CM nanofillers can disrupt bacterial fatty acid metabolism and ATP/nucleotide metabolism. Enhanced mechanical performance is achieved through superior filler-matrix coupling enabled by bisilanization. The formulation demonstrates low water sorption (< 40 µg mm ^{- 3}) over 3 months and high flexural strength (> 80 MPa). Antibiofilm activity and biosafety are further confirmed in an in vivo rat tooth-restoration model. This dual-antibacterial, bisilanized RBC offers promising clinical opportunities to durably restore teeth by effectively controlling biofilm, preventing caries recurrence, and reducing the risk of periodontal infections. The technology holds great potential for advancing restorative dentistry and promoting oral health.