Photocatalytic TiO2/HAP nanocomposite for antimicrobial treatment, promineralization, and tooth whitening†

Early dental caries and tooth staining are prevalent clinical conditions, so it is of great clinical significance to develop a multifunctional material. Photocatalytic therapies play a significant role in the medical field. However, the use of photocatalytic materials in the dental field is relatively limited. In this study, multifunctional titanium dioxide/nanohydroxyapatite (TiO₂/HAP) nanocomposites were synthesised using a hydrothermal method and investigated for their antibacterial properties, mineralization-promoting effects, tooth whitening capabilities, and biocompatibility. TiO₂ serves as a photocatalyst, facilitating antimicrobial treatment and improving teeth whitening through a photodynamic reaction. HAP, as a mineralization-promoting agent, effectively promotes enamel remineralization following plaque removal. The results of the whitening experiment indicated after treatment by TiO₂/HAP combined with blue light irradiation, the tooth color improved from C4 to A1. In a rat molar model of early caries, TiO₂/HAP effectively removed dental plaque and increased the calcium-to-phosphorus ratio to 1.58, further validating the results of the microhardness test. Meanwhile, TiO₂/HAP nanocomposites demonstrated good biocompatibility in vivo and did not significantly alter the oral microbial community. The results indicate that TiO₂/HAP plays a significant role in antimicrobial activity, remineralization, and tooth whitening, offering a novel strategy for the prevention and treatment of early caries and tooth staining.