A reusable BTO-based composite film for safe and convenient tooth whitening†

Dental surface staining is the most common problem in oral health care. The current mainstream treatment is still bleaching with high concentrations of hydrogen peroxide, which will not only cause enamel damage and tooth sensitivity but may also lead to periodontal soft tissue stimulation. Here, we have prepared a barium titanate (BTO)-based composite film doped with graphite (C) particles, which can gently and continuously produce hydroxyl radicals (˙OH) and superoxide anions (˙O₂⁻) through the piezoelectric catalysis and thermal catalysis induced by the oral chewing movement and temperature changes. This composite film can replace the reactive oxygen species produced by hydrogen peroxide, destroying the conjugated double bonds of the stained macromolecules, degrading the dye macromolecules into light compounds, and finally achieving tooth whitening, but without causing damage to tooth enamel and cells. In the future, this BTO-based composite film may become a promising strategy for oral health care.