A Bifunctional Zwitterion‐Modified Porphyrin for Photodynamic Nondestructive Tooth Whitening and Biofilm Eradication

Abstract Tooth staining and biofilm formation are major challenges for dental healthcare around the world. Herein, a bifunctional photodynamic dental therapy (PDDT) strategy is designed based on zwitterion‐modified porphyrin (ZMP) prepared by the conjugation of protoporphyrin IX (PP) and a superhydrophilic zwitterion moiety for tooth whitening and biofilm eradication. The electron donor–acceptor structure and water solubility of ZMP increases its reactive oxygen species output to ≈8 times compared with PP under purple light irradiation. Results show that this new strategy can not only nondestructively whiten teeth by degrading the chromogen, but also eradicate ≈95% of the biofilm by disintegrating the extracellular polymeric substances. This study highlights the superiority of ZMP as a photosensitizer and opens new avenues in exploring PDDT for clinical dentistry to whiten teeth and treat biofilm‐induced dental diseases.