牙齿美白剂及酸性饮料对釉质表面结构的影响

Effects of tooth whitening agents and acidic drinks on the surface properties of dental enamel

目的比较冷光牙齿美白胶贴和酸性饮料对离体牙釉质表面形貌以及Ca/P值和显微硬度的影响。方法分别用冷光牙齿美白胶贴、可乐、橙汁对新鲜离体牙表面进行涂覆处理(以生理盐水为对照组),经过即刻、7 d、14 d后分别用扫描电子显微镜观察处理前后离体牙的表面形貌和表面Ca/P值变化,用显微硬度仪检测处理前后釉质显微硬度的改变。结果处理后即刻,3个实验组的釉质表面均有脱矿现象,Ca/P值和显微硬度值均降低,明显小于对照组(P<0.05);7 d后逐渐升高,14 d后与对照组无明显差异(P>0.05)。结论牙齿美白剂对釉质有一过性脱矿作用,与日常饮用的酸性饮料相比,其脱矿属于正常范围,且随着时间推移,釉质可以发生再矿化。

Objective Using tooth whitening agents （bleaching clip） in vitro and acidic drinks, we conducted a compara- tive study of the changes in enamel surface morphology, Ca/P content, and hardness. Methods Tooth whitening glue pieces, cola, and orange juice were used to soak teeth in artificial saliva in vitro. Physiological saline was used as a control treatment. The morphology of the four groups was observed under a scanning electron microscope （SEM） immediately after the teeth were soaked for 7 and 14 d. The changes in Ca/P content and microhardness were analyzed. Results The enamel surfaces of the teeth in the three test groups were demineralized. The Ca/P ratio and the average microhardness were significantly lower than those of the control group immediately after the teeth were soaked （P〈0.05）. The Ca/P ratio and microhardness gradually increased after 7 d. No significant difference was observed between the control group and the test groups after 14 d （P〉0.05）. Conclusion Bleaching agents caused transient demineralization of human enamel, but these agents could induce re-mineralization and repair of enamel over time. Demineralization caused by bleaching covered a relatively normal range compared with acidic drinks and daily drinking.