光催化劑之矽鎂鐵氧化物複合材料作用於牙齒漂白

Abstract

隨著民眾對牙齒美觀的需求增加，牙齒美白已經發展成為牙科診所中較被患者追捧的美容項目。其中牙齒漂白技術因其操作簡便價格親民較為被大眾接納。牙齒漂白技術主要分為非活性牙齒漂白、居家漂白和診間漂白。如今市面上採用的漂白藥劑的主要成分大多含過氧化氫。高濃度的過氧化氫會提高牙齒漂白的效率，但同時也會帶來牙齒敏感、牙齒表面微結構改變、牙齒修復物變色、刺激口腔軟組織等副作用。 因此，降低過氧化氫的濃度，提升漂白效率，對於牙齒美白是有利的。本團隊研發出一種含二氧化矽(SiO2)、氧化鎂(MgO)和氧化鐵(Fe2O3)的複合材料光催化劑(簡稱為矽鎂鐵光催化劑)。使用此矽鎂鐵光催化劑並搭配光照後，可以在較低濃度的過氧化氫溶液中仍展現出良好的漂白效果。材料合成後採用化學分析電子能譜儀、電子顯微鏡、X光繞射等技術檢測矽鎂鐵光催化劑材料組成與型態;利用紫外光分光光譜儀和影像分析技術測定漂白功效;同時培養牙齦成纖維細胞來進行細胞生物相容性測試，最後測試矽鎂鐵光催化劑漂白時對牙釉質剪切黏著強度和牙齒表面粗糙度的影響。 結果顯示二氧化矽、氧化鎂和氧化鐵良好的結合在一起，氧化鐵在核心金屬球表面形成矽鎂鐵氧化物複合材料。此矽鎂鐵光催化劑無論是直接分解色素溶液或是體外對染色牙齒漂白皆能最大程度上激發低濃度過氧化氫溶液分解出羥基自由基從而達到最佳的漂白結果。MTT與細胞螢光的結果顯示此矽鎂鐵光催化劑擁有良好的生物相容性，且不會對牙齒表面微結構產生破壞，也不會影響複合樹脂的黏著。綜合以上結果可知，此矽鎂鐵複合材料光催化劑在牙齒漂白領域相當具有潛力，是一種漂白效果佳且生物相容性好的光催化劑。

Due to the aesthetic demand, tooth bleaching has become more popular nowadays. The strategies of tooth bleaching are mainly classified as non-vital bleaching, home bleaching and in-office bleaching. Most of the bleaching agents used hydrogen peroxide as the main ingredient. High concentrations of hydrogen peroxide have demonstrated the efficiency of in-office and home bleaching; meanwhile, it would increase the risks of tooth hypersensitivity, microstructure damage of tooth surface, discoloration of dental restorations and gingival irritation. Therefore, reducing the concentration of hydrogen peroxide and improving the bleaching efficacy can be beneficial for teeth whitening. In this study, we developed a photocatalyst containing silicon dioxide (SiO2), magnesium oxide (MgO) and iron oxide (Fe2O3) for tooth bleaching under UV light irradiation. After the material was synthesized, the composition and morphology of the photocatalyst were examined using X-Ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), X-ray diffraction (XRD) and other technologies; UV spectrometer and image analysis technology were used to determine the efficacy of bleaching. Human gingival fibroblasts were cultured and tested for cell biocompatibility. We also tested the effects of photocatalyst bleaching on enamel shear bond strength and tooth surface roughness. The results showed that silicon dioxide, magnesium oxide and iron oxide were well combined, and iron oxide forms a silicon-magnesium-iron oxide composite material on the surface of the core metal sphere. SiO2/MgO/Fe2O3 photocatalyst exhibits excellent decomposition of the dye solution or in vitro bleaching of stained teeth under the low- concentration hydrogen peroxide solution. The results of cell viability and immunofluorescence showed the SiO2/MgO/Fe2O3 photocatalyst has good biocompatibility and did not damage the microstructure of the tooth surface or affect the adhesion of the composite resin. Based on the above results, we concluded that the SiO2/MgO/Fe2O3 photocatalyst had good bleaching efficacy and biocompatibility, it showed great potential in the tooth bleaching.