ESR investigation of ROS generated by H2O2 bleaching with TiO2 coated HAp.
It is well known that clinical bleaching can be achieved with a solution of 30% hydrogen peroxide (H2O2) or H2O2/titanium dioxide (TiO2) combination. This study examined the hypothesis that TiO2 coated with hydroxyapatite (HAp-TiO2) can generate reactive oxygen species (ROS). ROS are generated via photocatalysis using electron spin resonance (ESR). The bleaching properties of HAp-TiO2 in the presence of H2O2 can be measured using hematoporphyrin litmus paper and extracted teeth. We demonstrate that superoxides (O2(•-)) and hydroxyl radicals (HO(•)) can be generated through excitation of anatase TiO2, rutile TiO2, anatase HAp-TiO2, and rutile HAp-TiO2 in the presence of H2O2. The combination of R HAp-TiO2 with H2O2 produced the highest level of HO(•) generation and the most marked bleaching effects of all the samples. The superior bleaching effects exhibited by R HAp-TiO2 with H2O2 suggest that this combination may lead to novel methods for the clinical application of bleaching treatments.
Division of Fixed Prosthodontics, Department of Oral and Maxillofacial Rehabilitation, Kanagawa Dental College, Yokosuka, Kanagawa, Japan.
Makiko
M
Saita
Kyo
K
Kobayashi
Kyou
K
Kobatashi
Fumihiko
F
Yoshino
Hiriko
H
Hase
Toru
T
Nonami
Katsuhiko
K
Kimoto
Masaichi-Chang-il
MC
Lee
D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D006861:Hydrogen Peroxide; D006878:Hydroxides / Q000737:chemistry; D055668:Photochemical Processes; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species / Q000737:chemistry*; D019097:Spin Trapping / Q000379:methods; D013481:Superoxides / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014073:Tooth Bleaching / Q000379:methods*; D014466:Ultraviolet Rays
D020099:Coated Materials, Biocompatible; D006878:Hydroxides; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D013481:Superoxides; C009495:titanium dioxide; C031356:hydroxide ion; D017886:Durapatite; D006861:Hydrogen Peroxide; D014025:Titanium