Bio-inspired temperature-responsive hydrogels for antibacterial oral protection and dental whitening with significant pyroelectric dynamic efficacy

Dental whitening, as one of the most popular procedures in aesthetic dentistry, has attracted significant attention from both clinicians and researchers. Herein, a bio-inspired wet-adhesive CD/TA 2 /SF/BM (CDT 2 FB) hydrogel was fabricated for dental whitening and broad-spectrum antibacterial protection. Silk fibroin (SF), L-3,4-dihydroxyphenylalanine (DOPA)-grafted chitosan (CD) and tannic acid (TA) were incorporated to mimic the adhesive mechanisms of barnacles and mussels. Under repeated cooling/heating cycles, BM heterojunction within the hydrogel exhibited an efficient intrinsic pyroelectric effect, facilitated the separation of electron-hole pairs, constructed a built-in microelectric field, and ultimately promoted the in-situ generation of •OH and •O 2 − radicals. Natural black stains on the dentition surface were successfully whitened in CDT 2 FB + ΔT group, achieving 8.1-fold enhancement in whiteness (color difference/ΔE: 26.6 ± 3.0). Notably, the group of CDT 2 FB + ΔT exhibited a strongest bactericidal activity, achieving a remarkable elimination rate of 93.8 ± 0.6% against E. coli and 89.8 ± 1.2% against S. aureus , respectively. Simultaneously, the hydrogel acted as a protective patch that isolated the dental surface from the acidic environment and inhibited glucose accumulation. Hence, the hydrogel was capable of maintaining enamel health and lowering cariogenic risk, delivering dual therapeutic and protective effects, and thus showed great potential for practical dental applications.