合成含金屬離子-組胺酸之中孔徑奈米粒子以促進牙齒漂白效率

Abstract

目前一般診所常見的冷光美白、雷射美白等所使用的美白藥劑，多為30%過氧化氫的漂白藥劑為主，利用光源(熱催化)來加速過氧化氫分解成氫氧自由基去分解牙齒中的色素，但是高濃度的漂白藥劑及此種光照漂白方法會產生一些副作用像是牙齒敏感、牙齒表面結構的改變、牙根吸收及對牙髓組織造成傷害…等。 本篇研究主要目的是合成出適合抓住過渡金屬離子的中孔洞奈米粒子(Mesoporous Silica Nanoparticles，簡稱MSN)，藉由已抓住過渡金屬離子的中孔洞奈米粒子來催化過氧化氫溶液，快速產生氫氧自由基去分解色素，縮短漂白的時間，減少漂白藥劑對牙齒的傷害。根據文獻指出過渡金屬具有催化過氧化氫的能力(Parra et al., 2004)，因此我們選用Fe(II)、Mn(II)這兩種過渡金屬離子當作催化劑。接著選用Orange II當作催化反應的染色指示劑，以紫外光/可見光分光光譜儀檢測這兩種金屬離子的漂白催化效果；結果顯示以Fe(II)-histidine-MSN的效果最好，而從照片觀察來看Mn(II)-histidine-MSN跟histidine-MSN似乎只有吸附的效果。接著將金屬離子催化劑應用在牙齒漂白上，將牙齒先以Orange II染色48小時，再用金屬離子催化劑催化過氧化氫溶液漂白已染色的牙齒，分析ΔE的結果顯示不管是在Enamel、Outer dentin還是Inner dentin，都是Fe(II)-histidine-MSN的漂白效果最佳。因此我們認為在相同時間內，金屬離子催化劑的漂白效果確實比沒有加催化劑的控制組好，未來或許可以試著再降低過氧化氫的濃度，去探討金屬離子催化劑是否也有很好的效果，或者再找尋漂白效果更好的過渡金屬離子，縮短漂白時間及降低過氧化氫溶液的濃度，減少漂白造成牙齒的副作用。 關鍵字: 中孔洞奈米粒子、過渡金屬離子、組胺酸、催化劑、牙齒漂 白

The In-office bleaching agent concentration is approximately 30% H2O2，and always using light sources or heat to accelerate the bleaching agent, for rapidly breakdown H2O2 to generated free radical (•OH), and then free radical (•OH) would attack the pigment in the tooth . But high concentration bleaching agent and using light accelerate bleaching method would have some side effects, like tooth hypersensitivity、change tooth surface and structure、root absorption and pulp thermal damage etc. The aim of this study was to synthesis mesoporous silica nanoparticles (MSN)for immobilized metal ion-histidine complex, then use Me-histidine-MSN to catalyst H2O2, generated free radical (•OH) rapidly. We could reduced duration of bleaching, and decrease the side effects of tooth bleaching. According the literature(Parra et al., 2004)，we utilized two metal ions(Fe2+and Mn2+ ) to catalyze the reaction rate of H2O2. We selected Orange II as an indicator for catalyst reaction. Spectrophotometer and picture was used to determine the most efficient metal ions in our established tooth stain model. The results revealed that Fe(II)-histidine-MSN had the greatest bleaching ability followed by Mn(II)-histidine-MSN and others. Subsequently, we apply the Me-histidine-MSN in tooth bleaching, first utilized Orange II solution to stain tooth for 48 hours, and then bleaching the stained tooth by Me-histidine-MSN and H2O2. The result of ΔE value revealed that whatever in Enamel、Outer dentin or Inner dentin, the Fe(II)-histidine-MSN had the greatest bleaching ability. So we thought that in the same bleaching time, the Me-histidine-MSN had the greatest bleaching ability than without metal catalyst. In the further, maybe we can reduce the concentration, and then to find Me-histidine-MSN still have good bleaching ability, or search the greatest bleaching ability metal catalyst. And we could reduce bleaching time and the concentration, and thereby, decrease the potential damage of H2O2 to tooth during tooth bleaching. Key words: Mesoporous silican nanoparticle, Transition metal ion, Histidine, Catalyst, Tooth bleaching