Kawamoto Kohji, Tsujimoto Yasuhisa
Department of Endodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
J Endod. 2004 Jan;30(1):45-50. doi: 10.1097/00004770-200401000-00010.
The mechanisms of bleaching of discolored coronal teeth using hydrogen peroxide (H2O2) were investigated. In a scanning-electron-microscopy study, the intertubular dentin and peritubular dentin were dissolved by high concentrations of H2O2, which is used for bleaching. The X-ray diffraction study showed that hydroxyapatite was not influenced by H2O2. In an electron-spin-resonance study, more hydroxyl radical (* OH) was detected as the H2O2 concentration was increased. When amino acids that are core components of dentin proteins, such as proline and alanine, were added to H2O2, the generation of * OH decreased, but there was no change when glycine was added. A nuclear-magnetic-resonance study showed that proline was degraded completely by H2O2, the structure of alanine changed slightly, and glycine was not affected by H2O2. It is suggested that H2O2 and * OH do not influence the inorganic tissue of dentin but attack the organic component of dentin. These facts suggest that * OH has the main role in tooth bleaching with H2O2.
研究了使用过氧化氢（H₂O₂）对变色牙冠进行漂白的机制。在一项扫描电子显微镜研究中，用于漂白的高浓度H₂O₂溶解了管间牙本质和管周牙本质。X射线衍射研究表明，羟基磷灰石不受H₂O₂影响。在一项电子自旋共振研究中，随着H₂O₂浓度的增加，检测到更多的羟基自由基（OH）。当向H₂O₂中添加牙本质蛋白的核心成分氨基酸（如脯氨酸和丙氨酸）时，OH的生成减少，但添加甘氨酸时没有变化。一项核磁共振研究表明，脯氨酸被H₂O₂完全降解，丙氨酸的结构略有变化，甘氨酸不受H₂O₂影响。提示H₂O₂和OH不影响牙本质的无机组织，但会攻击牙本质的有机成分。这些事实表明OH在H₂O₂牙齿漂白中起主要作用。
