不同pH值过氧化氢漂白影响人牙本质颜色及透明度的对比及机制初探

Effect of Different pH Hydrogen Peroxide Bleaching on Human Dentin Color and Transparency

目的:探讨不同pH值过氧化氢溶液对牙本质颜色和透明度的影响。方法:将30颗刚拔除的人前磨牙随机分为两组,每组15例,沿牙长轴剖开、去髓,使用pH=4.5和pH=7.0的两种过氧化氢溶液分别进行漂白,用Crystaleye电脑比色仪观察牙本质颜色和透明度的变化,以及与时间的关系,初步分析其机制。结果:pH=7.0过氧化氢溶液漂白1周后牙本质颜色变黄,透明度下降,基质金属蛋白酶活性下降。pH=4.5过氧化氢溶液漂白1周后牙本质颜色变黄,透明度下降,3周后部分牙本质颜色恢复,同时基质金属蛋白酶活性升高,两组差异有统计学意义(P<0.05)。结论::pH=7.0的过氧化氢溶液氧化性较强,对牙本质的破坏较大,pH=4.5过氧化氢溶液对牙本质破坏性略低。其机制与牙源性基质金属蛋白酶活性有关。

Objective： To investigate the effect of different pH value of hydrogen peroxide solution on dentin color and transparency. Methods： 30 recently extracted human premolars were randomly divided into two groups, 15 cases in each group. Along the long axis, the teeth were cut, removed of pulp, and bleached with, two hydrogen peroxide solution using the pH=4.5 and pH= 7.0. Changes of dentin color and transparency were recorded with Crystaleye computer eolorimeter as well as the relationship and time. A preliminary analysis was performed to learn its mechanism. Results： One week after the pH 7.0 hydrogen peroxide solution bleaching dentin became yellow, transparency decreased, the activity of matrix metalloproteinases decreased. One week after pH4.5 solution of hydrogen peroxide bleaching dentin became yellow, transparency reduced. Part of the dentin color restored after 3 weeks, and matrix metalloproteinase activity increased, with a significant difference between two groups （P〈0.05）. Conclusion： Alkaline hydrogen peroxide solution has strong oxidation resistance of dentin, great damage. Neutral hydrogen peroxide solution has slight dentin destruction. The mechanism is related to odontogenic matrix metalloproteinase activity.