Sono-Catalytic Tooth Whitening and Oral Health Enhancement with Oxygen Vacancies-Enriched Mesoporous TiO Nanospheres: A Nondestructive Approach for Daily Tooth Care.

Tooth discoloration and the breeding of oral microorganisms pose threats to both one's aesthetic appearance and oral health. Clinical whitening agents based on HO with high concentrations are effective in tooth whitening and bacterial elimination but may also cause enamel demineralization, gingival irritation, or cytotoxicity, necessitating professional supervision. Herein, leveraging sono-catalysis effects, a nondestructive and convenient tooth whitening strategy was developed, utilizing oxygen vacancies (OVs)-enriched mesoporous TiO nanospheres. The introduction of OVs leads to TiO bandgap narrowing, boosting the generation of reactive oxygen species (ROS) by TiO under ultrasound treatment. Additionally, through the chemocatalysis effect, the ROS yield can be further augmented by employing OVs-enriched TiO in conjunction with an extremely low concentration of HO (1%) during ultrasound treatment. Hence, under ultrasound treatment simulating daily tooth brushing using an electronic toothbrush, the combination of OVs-enriched TiO and 1% HO proves to be effective in whitening teeth stained by tea, coffee, and mix juice. Furthermore, the combination of OVs-enriched TiO and 1% HO demonstrates potent bacterial-killing and biofilm-eradicating effects under ultrasound treatment within an extremely short duration (5 min). Additionally, given the mesoporous structure, curcumin, serving as an anti-inflammatory agent, can be efficiently loaded into OVs-enriched TiO and then controllably released through ultrasound treatment. The curcumin-loaded TiO facilitates the transition of macrophages to the anti-inflammatory M2 phenotype, potentially alleviating oral inflammation induced by bacterial infection without showing any biotoxicity. The OVs-enriched TiO based sono-catalysis tooth whitening procedure provides the convenience of whitening teeth during daily brushing without requiring professional supervision.