Bionic wet-adhesive tooth band-aid with bidirectional anchoring to promote dentin remineralization

Tooth defects are regarded as “wounds” on the tooth. While remineralization therapies aim to rebuild tooth structures, challenges remain in protecting defects and delivering remineralization templates due to the wet and dynamic oral environment. Drawing from wound dressing, this study intends to construct a tooth dressing for the oral environment. Tannic acid (TA) was screened to crosslink fibroin protein (SF) and form internal anchoring through hydrogen bonding to fabricate a SF-TA (ST) tooth dressing matrix. Assisted by the drainage effect of the SF hydrophobic side chain on the interface, the system forms external anchoring to the tooth surface via phenolic hydroxyl groups and side chains. Notably, the bidirectional anchoring effect can be enhanced by calcium-phosphorus-enriched saliva, ensuring effective wet adhesion in the oral cavity. Loaded with an octuplet repeat of aspartate-serine-serine (8DSS) as a remineralization template, the SF-TA-8DSS (ST-8DSS) “tooth band-aid” maintains strong wet-adhesion to tooth surface under liquid contamination (bursting pressure above 780 mmHg) and delivers 8DSS into dentinal tubules (up to 100 µm over 14 days), promoting dentin remineralization. The proposed tooth band-aid offers an effective strategy for repairing tooth defects, combining mechanical reinforcement and wet adhesion through bidirectional anchoring for sustained mineralization under fluid contamination.