不同再矿化处理对漂白后釉质表面形貌及钙磷比的影响

目的 探究不同再矿化处理对漂白后釉质表面形貌及钙磷比的影响。方法 制备牛牙釉质样本，漂白处理后，随机分为5组：去离子水(DW)组；2%氟化钠(NaF)组；10%原花青素(PC)组；酪蛋白磷酸肽-无定形磷酸钙(CPP-ACP)组；PC+CPP-ACP组。用色差仪、扫描电镜、能谱仪和原子力显微镜分别检测样本漂白前、漂白后即刻及再矿化1周的颜色、表面形貌、元素和粗糙度变化。结果 各组间色差值无统计学意义(P>0.05)。扫描电镜显示，再矿化后各组均可见程度不一的矿物质沉积，PC+CPP-ACP组沉积物更明显。能谱仪显示，漂白后釉质表面钙磷比降低，再矿化后均有升高，NaF及PC+CPP-ACP组更高(P<0.05)。原子力显微镜显示，再矿化后各组均可见沉积物且粗糙度降低(P<0.05),PC+CPP-ACP组沉积物更明显、粗糙度更小(P<0.05)。结论 PC和CPP-ACP均能促进漂白后釉质再矿化，联合作用效果更佳。PC和CPP-ACP没有影响漂白效果。

Effect of remineralization procedures on surface morphology and Ca/P ratio of bleached enamel

Objective To study the effect of remineralization procedures on surface morphology and Ca/P of bleached enamel. Methods Enamel samples of bovine teeth were prepared and bleached with bleaching gel, and then randomly divided into five groups for different remineralization procedures:deionized water (DW) group; 2% NaF group; 10% procyanidins (PC) group; casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) group; PC+CPP-ACP group. Changes of color, surface morphology, elements and roughness were detected by chromometer, scanning electron microscopy, energy dispersive spectroscopy and atomic force microscopy before bleaching, immediately after bleaching and one week after remineralization, respectively. Results Significant differences in ΔE were not found among bleached groups (P>0.05). Mineral sediments of different degrees could be observed in all groups after remineralization procedures, especially in PC+CPP-ACP group. Energy dispersive spectroscopy showed that bleaching significantly reduced the Ca/P ratio (P<0.05). All remineralization treatment increased the Ca/P ratio. NaF and PC+CPP-ACP exhibited higher remineralization capacity in comparison to other groups (P<0.05). Atomic force microscopy showed that mineral sediments were observed and roughness was reduced in all groups after remineralization (P<0.05), and sediments were more obvious and roughness was much smaller in PC+CPP-ACP group (P<0.05). Conclusion PC and CPP-ACP could promote the remineralization on enamel surface after bleaching, and their combined effect was better. PC and CPP-ACP did not interfere with bleaching efficacy.