Götz Hermann, Klukowska Malgorzata A, Duschner Heinz, White Donald J
Institute of Applied Structure- and Microanalysis, Medical Faculty, Johannes Gutenberg University-Mainz, Mainz, Germany.
J Clin Dent. 2007;18(4):112-9.
This study examined the effects of elevated-concentration hydrogen peroxide tooth whitening strips on the surface and subsurface integrity of enamel, coronal dentin, and root dentin.
Sound human teeth were ground and polished to prepare a uniform substrate for bleaching. A cycling regimen included exposures to saliva, bleaching treatments, and fluoridated toothpaste. Bleaching was carried out with plastic strips containing hydrogen peroxide gel at 11.7 and 14% concentrations. A non-bleached group served as a control. Bleaching times measured up to 45 hours. Physical properties of tooth surfaces were assessed by microhardness, while surface morphological properties of teeth were examined by profilometry, surface Confocal Laser Scanning Microscopy (CLSM), and Variable Pressure Scanning Electron Microscopy (VP-SEM). Subsurface histomorphological effects on teeth were assessed by CLSM. Lastly, the influences of bleaching on tooth micro-chemical composition was studied by micro-Raman spectroscopy using a unique spectrometer in line, coupled to the CLSM via glass fiber.
Surface microhardness, profilometry, CLSM, and VP-SEM measures showed enamel and root dentin surfaces were unchanged with bleaching. CLSM micromorphological assessments demonstrated normal histology for bleached teeth on surface and subsurface enamel, DEJ, and dentin. Raman spectroscopy demonstrated no effects of bleaching treatments on the microchemical mineral composition of enamel and dentin. Bleaching treatments were observed to reduce background luminescence of enamel, DEJ, and dentin.
These results confirm that whitening strips delivering controlled doses of hydrogen peroxide at 11.7 and 14% concentrations do not produce changes in surface/subsurface histomorphology, surface microhardness, or micro-chemical mineral composition of teeth. The 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条对釉质、冠部牙本质和根部牙本质的表面及亚表面完整性的影响。
将健康人牙进行打磨和抛光，以制备用于漂白的均匀基底。循环方案包括暴露于唾液、漂白处理和含氟牙膏。使用含有浓度为11.7%和14%过氧化氢凝胶的塑料条进行漂白。未漂白组作为对照。漂白时间最长为45小时。通过显微硬度评估牙齿表面的物理性质，通过轮廓仪、表面共聚焦激光扫描显微镜（CLSM）和可变压力扫描电子显微镜（VP-SEM）检查牙齿的表面形态学性质。通过CLSM评估漂白对牙齿亚表面组织形态学的影响。最后，使用一台独特的在线光谱仪，通过玻璃纤维与CLSM耦合，通过显微拉曼光谱研究漂白对牙齿微化学成分的影响。
表面显微硬度、轮廓仪、CLSM和VP-SEM测量结果表明，漂白后釉质和根部牙本质表面未发生变化。CLSM微观形态学评估显示，漂白牙齿的表面和亚表面釉质、牙本质-釉质界（DEJ）和牙本质的组织学正常。拉曼光谱表明，漂白处理对釉质和牙本质的微化学矿物成分没有影响。观察到漂白处理可降低釉质、DEJ和牙本质的背景发光。
这些结果证实，输送浓度为11.7%和14%的可控剂量过氧化氢的美白条不会导致牙齿的表面/亚表面组织形态学、表面显微硬度或微化学矿物成分发生变化。显微拉曼光谱中记录的漂白剂对牙齿发光的影响可能作为漂白效果的内部特征，值得进一步研究。
