科学美国人60秒 SSS 海狸牙齿的奥秘（在线收听）

Ah yes.The ol' fluoride rinse at the dentist. Not pleasant. But hey, good for your teeth, right?

没错，这是牙医洗牙用的含氟漱口水。确实够闹心的。但毕竟对你的牙齿有益不是吗?

Well now materials scientists have been able to figure out why—by mapping the nanostructure of tooth enamel. If you zoom way in, tooth enamel looks almost like the weave of a basket."Where each thread is made from thousands of nanowires."Derk Joester, of Northwestern University.

现在材料科学家们通过绘制牙釉质的纳米结构已经知晓其中的原因。如果放大牙釉质，它与篮子的纹理非常相近。每条线都由成千上万的纳米线条组成。西北大学德克·乔斯特尔说道。

And in between those crystalline nanowires,Joester and his colleagues discovered a sort of amorphous glue.And that's where the fluoride hangs out, helping to stave off an acid attack of the enamel—in other words, a cavity.But the researchers found something that works even better than fluoride: iron.And they found it in beaver teeth.

而在这些晶状纳米线中，乔斯特尔和同事们发现了一种非固定形状的胶质。而氟化物就在这里聚集，帮忙延缓阻挡牙釉质的酸蚀—换句话说抑制蛀牙。但研究人员发现了一样比氟化物效果更好的物质：那就是铁。他们是在海狸的牙齿中发现了它。

"Beavers don't get caries. Chewing through wood is a very good way to clean your teeth."But another reason, they say, is the iron-enriched glue in beaver enamel—which was even more acid-resistant than fluoride-treated enamel.

海狸不会患上龋齿。咀嚼木头是一种很好的清洁牙齿的方式。但他们称另一个原因则是海狸牙釉质中富含铁的胶质—相比氟这种牙釉质在耐酸性上更胜一筹。

The findings are in the journal Science.

这项研究已经在《科学》杂志上发表。

Of course iron-rich enamel comes with an unfortunate side effect: reddish-brown teeth But Joester says future human dental treatments that employ iron might find a way around that.

当然富含铁的牙釉质有着副作用：那就是会使牙齿变成红褐色。但乔斯特尔表示未来牙齿治疗方面会采用铁进行，应该可以找到相关解决办法。

"We have the entire periodic table to play with minus a few things that are not too healthy. So I'm sure we can come up with a way to do what the beaver does but do it better and do it in a way that still maintains a nice smile."

我们有整个周期可以解决那些并不健康的治疗手段。所以我相信我们能想出办法像海狸那样，而且在继续保持洁白笑容这方面会做得更好。