A bio-based superhydrophobic pit and fissure sealant for enhanced stability and anticaries application

Dental caries is one of the most prevalent chronic diseases worldwide, with most lesions occurring in occlusal pits and fissures. To prevent occlusal caries, pit and fissure sealants are considered one of the most effective measures. However, their anticaries effect are often compromised by secondary caries resulting from biofilm accumulation. Furthermore, traditional sealants based on bisphenol A glycidyl methacrylate (Bis-GMA) may release bisphenol A (BPA), raising concerns about potential endocrine disruption. In this study, we developed a bio-based superhydrophobic pit and fissure sealant by utilizing isosorbide dimethacrylate (IM) as a bio-based resin matrix, fluorinated methacrylate (FMA) as a low-surface-energy component, and a combination of micro- and nano-sized SiO₂ to construct a micro-nano hierarchical surface architecture, after light curing treatment. The bio-based micro-nano structured superhydrophobic pit and fissure sealant (m-n SUP) retained superhydrophobicity after immersion in artificial saliva for 5 days, thermocycling for 5000 cycles, pH cycling for 5000 cycles, tape peeling for 100 cycles, and sandpaper abrasion for 40 cycles. m-n SUP also exhibited favorable mechanical properties and enamel bonding comparable to those of the commercial sealant, together with favorable marginal sealing performance. Moreover, m-n SUP exhibited good cytocompatibility, and markedly reduced salivary mucin adsorption and provided sustained inhibition of the initial adhesion and biofilm formation for five representative oral cariogenic bacteria over 72 h. In a rat model, m-n SUP effectively reduced the incidence and severity of occlusal carie. Overall, this bio-based superhydrophobic pit and fissure sealant can provide a promising bio-based material strategy for pit and fissure caries prevention.