金属イオン修飾による二酸化チタン光触媒の可視光応答性付与と歯科応用のための基礎研究  [in Japanese] Visible Light Responsibility of Titanium Dioxide Photocatalyst by Metal Ion Decoration and Basic Research into Its Dental Application  [in Japanese]

従来,紫外光が不可欠であった二酸化チタン(TiO_2)光触媒を歯科に応用するために,金属イオン修飾により可視光応答性を付与し,その効果を色素分解試験で評価し,処理条件の最適化を図った.光触媒能は金属イオン/TiO_2量比に依存し,0.3μmのTiO_2粉末ではAg/TiO_2量比が30μg/gの条件において可視光で最も優れた触媒効率を示した.その応用として,ゾルーゲル法でTiO_2コーティングしたガラス板を用いた抗菌試験では,controlに比較してStreptococcus mutansに対する明らかな抗菌作用が確認された.さらに歯牙漂白試験でも漂白前後で視覚的,数値的に審美性の改善が認められた.可視光応答性の付与と触媒効率の増大により抗菌作用,歯牙漂白も十分に可能であり歯科臨床への応用の可能性が示唆された.

Although titanium dioxide photocatalyst is usually initiated only by ultraviolet in radiation, visible light responsiveness after metal ion processing was investigated by examination of the decomposition of methylene blue pigment and optimal processing conditions were studied. The photocatalyst effect depended on metal ion/TiO_2 ratio during treatment with metal ion solution. Using a 0.3 μm powder, the optimal catalyst efficiency under visible light was obtained with a Ag/TiO_2 ratio of 30 μg/g. An antibacterial effect on Streptococcus mutans was clearly confirmed on titanium dioxide film formed by the sol-gel method on a glass plate and decorated with metal ion. Dentition bleaching was also successfully carried out. Thus visible light responsiveness and an increase in catalyst efficiency were obtained, enabling antibacterial activity and dentition bleaching. These findings suggest the applicability of photocatalyst in dental practice.