Josey A L, Meyers I A, Romaniuk K, Symons A L
Department of Dentistry, University of Queensland Dental School, Brisbane, Australia.
J Oral Rehabil. 1996 Apr;23(4):244-50. doi: 10.1111/j.1365-2842.1996.tb00848.x.
This study examined the effect of a nightguard vital bleaching procedure on enamel surface morphology and the shear bond strength of a composite resin luting cement to enamel. Extracted human teeth were bleached for 1 week using a vital bleaching product. Control teeth were brushed with a fluoride toothpaste and processed similarly to the bleached teeth, however the bleaching product was substituted with artificial saliva in the night guards. Teeth were stored in artificial saliva for 24 h, 1, 6 or 12 weeks and then examined for any surface changes using light and scanning electron microscopy. The effect of etching surfaces with 37% phosphoric acid was examined at the scanning electron microscope level. The shear bond strength of composite resin luting cement to both buccal and lingual surfaces of bleached and control teeth was determined. Light microscopy investigation suggested the bleaching process resulted in a loss of mineral from enamel which was evident 24 h after bleaching and was sustained following 12 weeks storage in artificial saliva. Scanning electron microscopy showed a definite change in the surface texture of the bleached enamel surface. Acid etching of the bleached enamel surface produced loss of prismatic form and the enamel appeared overetched. The mean shear bond strength between composite resin luting cement and etched enamel tended to be lower for bleached enamel surfaces, however no significant difference in shear bond strength was noted between control and experimental groups. The results of this study suggest that bleaching resulted in changes to the surface and subsurface layers of enamel. Although surface changes were observed in the etched enamel, the shear bond strength of composite resin luting cement to etched bleached enamel appeared to be clinically acceptable.
本研究考察了夜间护齿活髓漂白程序对牙釉质表面形态以及复合树脂粘结水门汀与牙釉质之间剪切粘结强度的影响。使用一种活髓漂白产品对拔除的人牙进行为期1周的漂白。对照牙用含氟牙膏刷牙，并进行与漂白牙相似的处理，不过在夜间护齿中用人造唾液替代漂白产品。将牙齿保存在人造唾液中24小时、1周、6周或12周，然后用光镜和扫描电子显微镜检查是否有任何表面变化。在扫描电子显微镜水平上检查用37%磷酸蚀刻表面的效果。测定复合树脂粘结水门汀与漂白牙和对照牙颊面及舌面的剪切粘结强度。光镜研究表明，漂白过程导致牙釉质矿物质流失，这在漂白后24小时就很明显，并在人造唾液中保存12周后仍持续存在。扫描电子显微镜显示漂白牙釉质表面的质地有明显变化。漂白牙釉质表面的酸蚀导致棱柱形态丧失，牙釉质出现过度蚀刻。对于漂白牙釉质表面，复合树脂粘结水门汀与蚀刻牙釉质之间的平均剪切粘结强度往往较低，然而对照组和实验组之间在剪切粘结强度上未观察到显著差异。本研究结果表明，漂白导致牙釉质表层和次表层发生变化。虽然在蚀刻牙釉质中观察到了表面变化，但复合树脂粘结水门汀与蚀刻漂白牙釉质之间的剪切粘结强度在临床上似乎是可以接受的。
