Götz Hermann, Duschner Heinz, White Donald J, Klukowska Malgorzata A
Institute of Applied Structure and Microanalysis, Medical Faculty, Johannes Gutenberg-University, Mainz, Germany.
J Dent. 2007 Jun;35(6):457-66. doi: 10.1016/j.jdent.2007.01.004. Epub 2007 Mar 6.
This study examined the effects of elevated concentration hydrogen peroxide tooth whitening treatments on tooth surface and subsurface integrity.
Sound human molars were ground and polished to prepare an uniform substrate for bleaching treatments. A cycling treatment included alternating ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching was carried out with prototype bleaching strips containing hydrogen peroxide gel at 13% and 16% concentrations. A non-bleached group was used as a control. Treatments included 28h of total bleaching exposure in vitro. Surface color was measured prior to and following bleaching. Effects of bleach on physical properties of tooth surfaces were assessed by microhardness measures on enamel. Ultrastructural effects were examined by surface and subsurface confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) techniques. In addition, the effects of bleaching on tooth micro-chemical composition were studied by Raman spectroscopy combined with CLSM technique.
Color assessments confirmed significant ex vivo tooth bleaching. Surface microhardness and VP-SEM (variable pressure SEM) measures revealed no deleterious effects on the enamel surfaces. CLSM micromorphological assessments supported the safety of hydrogen peroxide bleaching strips both on surface and subsurface enamel, DEJ and dentin ultrastructure. Raman spectroscopy analysis demonstrated no obvious effects of bleaching treatments on the micro-chemical composition of enamel and dentin. Significant effects of bleaching were seen in reducing background luminescence of Raman spectra obtained from enamel and dentin.
These results confirm that hydrogen peroxide whitening strips do not produce changes in surface/subsurface histomorphology, surface microhardness and micro-chemical composition of teeth. Effects of bleaches on tooth luminescence recorded in micro-Raman spectroscopy may serve as an internal signature to bleaching effects and warrant further study.
本研究考察了高浓度过氧化氢牙齿美白治疗对牙齿表面及次表面完整性的影响。
将完好的人磨牙进行打磨和抛光，以制备用于漂白治疗的均匀基底。循环治疗包括在控制温度和治疗时长的条件下，将离体人唾液暴露与漂白治疗交替进行。使用含13%和16%浓度过氧化氢凝胶的原型漂白条进行漂白。以未漂白组作为对照。治疗包括体外总共28小时的漂白暴露。在漂白前后测量表面颜色。通过对牙釉质进行显微硬度测量来评估漂白对牙齿表面物理性能的影响。通过表面和次表面共聚焦激光扫描显微镜（CLSM）以及扫描电子显微镜（SEM）技术检查超微结构效应。此外，结合CLSM技术，通过拉曼光谱研究漂白对牙齿微化学成分的影响。
颜色评估证实离体牙齿有显著漂白效果。表面显微硬度和可变压力扫描电子显微镜（VP - SEM）测量结果显示对牙釉质表面无有害影响。CLSM微观形态学评估支持过氧化氢漂白条对牙釉质表面及次表面、牙本质 - 釉质界（DEJ）和牙本质超微结构的安全性。拉曼光谱分析表明漂白治疗对牙釉质和牙本质的微化学成分无明显影响。在降低从牙釉质和牙本质获得的拉曼光谱的背景发光方面观察到漂白有显著效果。
这些结果证实过氧化氢美白条不会使牙齿的表面/次表面组织形态学、表面显微硬度和微化学成分发生变化。微拉曼光谱中记录的漂白对牙齿发光的影响可能作为漂白效果的一种内在特征，值得进一步研究。
