Nondestructive Piezoelectric Nanocomposite Sonodynamic Toothbrush for Synergistic Dental Disinfection and Whitening

Over 3.47 billion people worldwide suffer from dental health and aesthetic issues, however, existing commercial toothbrushes lack synergistic antibacterial and whitening functions and fail to prevent biofilm accumulation and progressive staining. Here, we develop novel sonodynamic bifunctional piezoelectric nanocomposites by integrating piezoelectric Au@BTO nanoparticles into a porous elastomer matrix, enabling synergistic disinfection and whitening in a biosafe and efficient manner during daily toothbrushing. These nanocomposites exhibit superior mechanical and piezoelectric stability under continuous ultrasound stimulation for 30,000 s, along with robust andcontrollable generation of reactive oxygen species (ROS) based on a piezocatalytic mechanism. Under physiological conditions, the piezoelectric nanocomposites demonstrate highly efficient and durable antibacterial activity against Gram-positive S. aureus and S. mutans as well as Gram-negative E. coli and P. gingivalis (>99% efficacy), while preserving >95% oral cell viability. When integrated into an innovative Piezo-brush, the system maintains structural integrity for ∼5 months under daily toothbrushing and achieves 96% biofilm reduction and nondestructive whitening (CIELab color difference = 70.3, 0.6% Vickers hardness reduction), significantly outperforming existing functional toothbrushes and commercial products. This work develops a piezoelectric sonodynamic toothbrush for daily dental care, offering avenues for advanced biodevices in cosmetics, wound healing, and medical implants.