关于牙齿美白你应该知道的一些事

Ask Well: Whiter Teeth

关于牙齿美白你应该知道的一些事

Question: What is the healthiest and most effective way to whiten your teeth?

问：想要美白牙齿，最健康且最有效的方法是什么?

Answer: There is no shortage of ways to treat tooth discoloration: strips, rinses, brush-on gels and toothpastes sold at pharmacies; bleaching treatments at the dentist; trays bought at the dentist’s office for home use. The bottom line is all these methods work, but some require patience, and others a tolerance for painful sensitivity. And results will be only temporary.

答：治疗牙齿变色的方法有很多：药店出售的美白牙贴、漱口水、牙齿美白凝胶和牙膏;到牙科诊所做牙齿漂白;或者从牙科诊所购买适合家庭使用的美白牙托等。基本上说，上述所有方法都有用，不过它们要么起效慢，需要付出点耐心;要么需要忍受令人不舒服的牙齿敏感。效果维持的时间也很短暂。

Higher concentrations of hydrogen peroxide, a bleaching agent used in many whiteners, can be delivered in a dentist’s office, so those procedures tend to be quicker than drugstore aids. But tooth sensitivity and gum irritation can occur, and the higher the concentration of the peroxide used, the more severe these side effects are likely to be.

在牙科诊所里进行的程序可能会用到高浓度的过氧化氢(许多增白剂中都含有的一种漂白剂)，因此往往比从药店中买到的产品见效更快。但它们可能会引起牙齿敏感和牙龈发炎，而且所使用的过氧化物浓度越高，副作用可能就越严重。

More aggressive treatment isn’t necessarily more efficacious, either. A randomized trial of 90 patients found that use of a home bleaching tray with a 10 percent carbamide peroxide gel for two weeks offered the same degree of whitening as two in-office sessions using 35 percent hydrogen peroxide with light, which some dentists use because it supposedly activates bleaching agents.

较为积极的治疗手段效果未必就更好。一项以90名患者为研究对象的随机试验发现，使用含10%过氧化脲(碳酰胺过氧化氢)的家用美白牙托两周对牙齿的漂白效果，与在牙科诊所做两个35%过氧化氢加光美白疗程(据说光可以激活漂白剂，所以某些牙医会使用它)的效果相同。

Some dentists also use heat or even lasers to activate bleaching agents. But a 2007 systematic review of evidence in the journal Dental Materials found no added benefit from heat, light or lasers and suggested these methods “may have an adverse effect on pulpal tissue,” the soft material in the tooth’s center. If pulp is injured, it may require a root canal to fix.

一些牙医也使用热甚至激光来激活漂白剂。但2007年发表在《牙科材料学》杂志(Dental Materials)上的一篇对有关证据的系统性综述显示，热、光或激光都不能带来额外的增益，并指出这些方法“可能对牙髓组织(牙齿内部的软组织)造成不良影响”。如果牙髓受到损伤，可能会需要进行根管治疗。

Heat and hot lights can also have a dehydrating effect on teeth, which can make them look whiter. It can take weeks for the teeth to rehydrate and slightly darken.

热和热光也会造成牙齿脱水，使其看起来更白。牙齿复水大约需要几周的时间，而且这会使牙齿稍微变暗。

Dr. Ronald D. Perry, the director of the Gavel Center for Restorative Research at Tufts University School of Dental Medicine, said that over all, “the light doesn’t really do anything, but the marketing behind it is so powerful.”

塔夫茨大学牙医学院Gavel牙科修复研究中心(Gavel Center for Restorative Research at Tufts University School of Dental Medicine)的主任罗纳德·D·佩里博士(Dr. Ronald D. Perry)说，总而言之，“光并没有什么真正的效果，但它背后的市场营销却非常强大。”

Before any bleaching, even when it’s done at home, a dentist should check fillings and crowns, because, Dr. Perry said, applying peroxide to a restoration that is no longer perfectly sealed will be very sensitive.

在进行任何牙齿漂白程序(哪怕是在家里进行)之前，牙医应检查牙齿填充物以及牙冠，佩里博士说，这是因为，如果牙体修复物不再完全密封，对其施用过氧化氢将会造成严重的敏感。

In a 2014 review of tooth whitening studies, Clifton Carey, a professor at the University of Colorado School of Dental Medicine, warned that fillings that are designed to match the tooth’s color might get more yellow after even drugstore whiteners. Or, if teeth get whiter, and a filling doesn’t, it might stand out.

在2014年的一项对牙齿美白研究的综述中，科罗拉多大学牙医学院(University of Colorado School of Dental Medicine)的教授克利夫顿·凯里(Clifton Carey)警告说，即使使用从药店购买的增白剂，也可能使原本与牙齿颜色相匹配的牙体修复物变得更黄。又或者，牙齿被漂白了，没有同样被漂白的牙齿填充物就会变得很显眼。

Not all staining is alike. It can be caused by external factors like wine, coffee, cola and smoking, and bleaching is effective against these. Aging is another culprit, as enamel wears down and the yellower dentin that lies beneath becomes visible. Bleaching does work on older teeth, too.

此外，各种牙渍也不是完全一样的。它可能是由外部因素，如酒、咖啡、可乐和吸烟引起的，做牙齿漂白对这类牙渍很有效。衰老是牙齿变黄的另一个原因：随着牙釉质的磨损，其下颜色较黄的牙本质显露了出来。做牙齿漂白对此也有一定效果。

Unfortunately, it’s tricky to say how long the results of tooth whitening will last. A nightly merlot drinker with freshly lightened teeth may re-stain them in a month or two.

遗憾的是，很难说牙齿美白的效果能持续多久。如果每晚都饮用梅洛葡萄酒(merlot)，那么不出一两个月，刚被洗白的牙齿可能就又被染回去了。