Oral　diseases　caused　by　dental　biofilms　(e.g.,　caries　and　periodontitis)　remain　a　global　health　burden,　while　conventional　therapies　suffer　from　inefficacy,　safety　risks,　and　high　costs.　Here,　we　propose　a　plasmon-enhanced　piezocatalytic　strategy　leveraging　silver-decorated　barium　titanate　nanowires　(BTNW-Ag)　for　simultaneous　biofilm　eradication　and　tooth　whitening.　Under　ultrasound　and　biocompatible　green　light　stimulation,　the　piezoelectric-induced　electric　field　of　BTNWs　promotes　reactive　oxygen　species　(ROS)　generation　via　efficient　electron-hole　pair　separation,　while　also　driving　hot　electron　injection　from　Ag　nanoparticle-induced　localized　surface　plasmon　resonance,　thereby　enhancing　ROS　production.　Consequently,　BTNW-Ag6　achieves　99.4%　pigment　degradation　within　20　mins　and　over　99.9%　bacterial　eradication　within　8　mins.　Notably,　antibacterial　rates　of　97.4%　against　Porphyromonas　gingivalis　and　84.2%　against　Streptococcus　mutans　are　obtained　within　4　mins.　Furthermore,　simulated　daily　tooth　brushing　(2　mins,　twice　daily)　with　BTNW-Ag6　inhibits　biofilm　growth　and　prevents　enamel　demineralization　induced　by　biofilm-derived　acids.　Additionally,　rapid　tooth　whitening　by　BTNW-Ag6　is　achieved　within　3　h　without　causing　enamel　damage,　which　is　superior　to　hydrogen　peroxide　approach.　This　plasmon-mediated　piezocatalytic　strategy　offers　a　biocompatible,　cost-effective,　and　versatile　solution　for　dual-action　dental　care,　pioneering　a　new　paradigm　for　accessible,　at-home　oral　hygiene　treatments.