Effect of Bleaching Containing Polydopamine and Chitosan-Modified TiO₂ on the Level of Brightness and Microhardness of Teeth

Teeth bleaching techniques generally use high concentrations of bleaching agents such as H₂O₂, which can harm dental health. Therefore, an alternative method is needed to minimize the use of H₂O₂. The aim of this study was to determine the characteristics and effectiveness of a teeth-whitening gel made from polydopamine and chitosan-modified TiO₂. The research phase began with the extraction of TiO₂ from Tulungagung sand using the leaching method, and then the TiO₂ was modified with polydopamine and chitosan. XRD, FTIR, and TEM were used to characterize the fabrication results. The results of XRD analysis showed that the diffraction peaks of polydopamine and chitosan-modified TiO₂ had the characteristics of anatase phase TiO₂. Functional groups of polydopamine and chitosan-modified TiO₂ were identified from the results of FTIR analysis. The TEM image showed the spherical shape with a core-shell structure, where the TiO₂ particles were covered with polydopamine and chitosan. The addition of H₂O₂ at 3% to the polydopamine and chitosan-modified TiO₂ gel transformed it into a tooth whitening agent. After that, the teeth without soaking and those soaked in cola were bleached with the whitening gel using visible light irradiation three times for 15 min each time. The bleaching results showed that the 0.25-g polydopamine-modified TiO₂ formula whitening gel effectively whitened teeth without causing a significant change in the microhardness value of the tooth surfaces, even at low concentrations of H₂O₂.