Self-Bactericidal and Long-Lasting Resin Nanocomposites with Pyrocatalytic Activity Regulated by Oral Temperature Fluctuation

The design of antibacterial functions in dental resin composites is a key approach to preventing secondary caries. Although conventional composite resins incorporated with antimicrobial agents can indeed exhibit bactericidal effects, these lack long-lasting antimicrobial activity and may exert cytotoxic effects, thus, causing biosafety concerns. Here, we developed a universal, nondestructive, and self-bactericidal strategy for fabricating dental resin nanocomposites without additional devices or power sources. This was achieved by incorporating a ceramic nanofiller with pyrocatalytic activity, which is activated by ubiquitous oral activity-induced temperature fluctuations. By optimizing the content of BaSrTiO₃ (BST) pyroelectric fillers, the BST-resin nanocomposites exhibited a positive pyroelectric effect, as well as reactive oxygen generation capacity under physiological temperature fluctuations associated with food/drink intake and speech. The initial adhesion and growth of <i>S. mutans</i> were significantly inhibited by pyroelectric BST-resin nanocomposites. Subsequent biofilm formation was suppressed by pyroelectric effects activated by temperature fluctuations. Moreover, the pyrocatalysis-based resin nanocomposites displayed excellent therapeutic biocompatibility and excellent mechanical properties, which are comparable to those of commercial resins. Hence, our findings provide an innovative strategy for addressing the antibacterial technical requirements of dental resin nanocomposites.