Beauty is only ____1____. And the beauty of shiny white teeth is even less deep. Because a new study shows that fluoride forms a thinner protective shield than experts thought it did. The results appear in the surface science journal Langmuir.
American consumers spend more than $50 billion a year fighting cavities. When we realized that fluoride could help, we put it in our drinking water, our ____2____ and our mouthwash. But how does fluoride work its magic? Many figured that fluoride chemically reacts with the main mineral in enamel to form a thick, decay-resistant veneer. But the latest research ____3____ that idea in the teeth.
Scientists in Germany used x-ray photoelectron spectroscopy to get a detailed image of the surface of a treated tooth. And they found that the protective covering is actually only 6 nanometers thick. That’s about a fifteen-thousandth as thick as a sheet of paper. And a layer that skimpy would likely be ____4____ by ordinary chewing.
How fluoride keeps the tooth fairy away is a mystery that researchers are still working to ____5____. In the meantime, we may not know how it works, but we know that it works. So keep brushing.
【视听版科学小组荣誉出品】
skin deep toothpaste kicks worn away unravel
氟化物在牙科领域如何发挥作用仍是一个谜 美丽只是外表而已，一口洁白闪亮的牙齿甚至更“肤浅”。这么说是因为一项新研究表明氟化物形成的保护膜比专家们料想的还有薄。研究结果发布在《朗缪尔》（Langmuir）杂志上，是其封面报道。 美国消费者每年花在消灭蛀牙上的费用超过500亿美元。当我们意识到氟有助于保护牙齿，我们就把它放入我们的饮用水、牙膏和漱口水中。但是氟是如何发挥其魔力的？许多人认为氟跟牙釉质中的主要矿物质发生化学反应，形成一层厚厚的、抗蛀龋的保护面。不过这项最新研究颠覆了我们对牙齿的这种想法。 德国科学家利用X射线光电子光谱法绘制出一个治疗过的牙齿表面的详细图像。他们发现，保护敷层实际上只有6纳米厚，大概是一张纸的千分之十五的厚度。而这样薄薄的一层只是普通的咀嚼就会被磨损殆尽。 氟是如何保护牙齿让牙仙女远离我们是一个研究人员仍在努力解开的谜。在此期间，我们不知道它是如何工作的，但我们知道，它的确在发挥作用。因此，请坚持不断地刷牙吧。