Study on the antibacterial and remineralization effects of UCNPS probe with pH/ light dual response on early caries

Dental caries is regarded as the most widespread non - infectious disease in humans, primarily induced by acidogenic bacterial biofilms, which results in the demineralization and dissolution of dental hard tissues. In this study, a socket sealant was designed to prevent dental caries and promote tooth remineralization. The sealant can function under the acidic conditions (pH < 5.5) of biofilm infection. Under near - infrared light (980 nm) irradiation, graphene oxide (GO) is excited to generate resonance energy transfer (FRET). It then intelligently responds to green fluorescence (NaYF 4 ) to signal the onset of caries. Simultaneously, it releases MgO and mineralized ions (Mg 2+ ) to regulate the cariogenic acidic environment. Moreover, owing to the outstanding photothermal and photodynamic effects of GO, this material can further strengthen the destructive impact on bacterial biofilm by inhibiting bacterial adhesion under 980 - nm near - infrared light irradiation. Most significantly, the material can not only reverse the caries microenvironment at the pH and microbial levels but also facilitate the self - healing of demineralized teeth in terms of microstructure and mechanical properties.