美国国家公共电台 NPR Navigating The 'Aisle Of Confusion' To Whiten Your Teeth

 

DAVID GREENE, HOST:

Right from how smells can make us more attractive, let's turn to a multibillion-dollar global industry that is devoted¹ to making you look more attractive, teeth whitening. Just walk into any pharmacy². Go online. You'll see them - toothpastes, gels and strips and paint-on bleaches⁴, all with big promises to give you a bright, white smile. So tell us, NPR's Patti Neighmond, do these things work?

PATTI NEIGHMOND, BYLINE⁵: Not all tooth stains are the same. Some are mostly on the surface of the teeth and come from the food and liquid we consume. Dentist Ruchi Sahota.

RUCHI SAHOTA: Coffee, tea, red wine.

NEIGHMOND: And foods with vibrant⁶, yellow spices, like turmeric or tar⁷ and nicotine⁸. Sahota says these surface stains can be reduced with routine brushing, flossing and professional cleaning in the dentist's office. But there are some deeper stains you just can't avoid that come with age and years of chewing.

SAHOTA: The hard, outer shell of the tooth can start to get thinner and start to have these cracks over time.

NEIGHMOND: Literally⁹ millions of micro-cracks that can fill up with stain. And the thinner enamel¹⁰ allows the inner core of the tooth to be more visible.

SAHOTA: That inner core of the tooth is more yellow than the white enamel.

NEIGHMOND: This is where bleaching¹¹ agents come in. They can penetrate¹² that core and turn the tooth whiter again, typically two to seven shades lighter¹³. And that brings us to what some call the dental aisle¹⁴ of confusion.

SAHOTA: Because there are so many options. And you just get confused standing¹⁵ there, trying to figure out which option is the best.

NEIGHMOND: It's not easy. The strips, the gels, the paint-on bleaches aren't regulated by the FDA because it considers them cosmetic¹⁶. The American Dental Association offers an alternative, an ADA seal of acceptance. Chemist Jamie Spomer directs the program and says, when a manufacturer applies for the seal, an independent panel of dentists analyzes¹⁷ the data and performs studies of their own.

JAMIE SPOMER: The seal is rooted in science. When a consumer sees the ADA seal on a product, it is a symbol that an independent panel reviewed and approved that product for its safety and effectiveness.

NEIGHMOND: Numerous toothpastes carry the ADA seal. But so far, only one over-the-counter bleaching product does. Even so, many of the products that don't carry the seal can be effective, Sahota says, if used as directed. Most will cause tooth sensitivity during the bleaching process and, if you're not careful, other problems as well.

SAHOTA: Oftentimes, the products can leak onto the gums and cause sensitivity. It can basically bleach³ and blanch¹⁸ the gums.

NEIGHMOND: A safer but more costly¹⁹ option is to go to the dentist's office. A custom-made, take-home tray, which hugs the teeth and ensures the gel's evenly applied²⁰, costs around $400. Or have bleach applied in the dentist's office. Gums are protected by rubber, and bleach concentrations are high enough that whitening can occur in just an hour or two. That will cost you around a thousand dollars or more. Patti Neighmond, NPR News.

(SOUNDBITE OF WINDSOR AIRLIFT'S "THE CALL OF THE FOREST")

1 devoted   

adj.忠诚的，忠实的，热心的，献身于...的

参考例句：

• He devoted his life to the educational cause of the motherland.他为祖国的教育事业贡献了一生。
• We devoted a lengthy and full discussion to this topic.我们对这个题目进行了长时间的充分讨论。

2 pharmacy   

n.药房，药剂学，制药业，配药业，一批备用药品

参考例句：

• She works at the pharmacy.她在药房工作。
• Modern pharmacy has solved the problem of sleeplessness.现代制药学已经解决了失眠问题。

3 bleach   

vt.使漂白；vi.变白；n.漂白剂

参考例句：

• These products don't bleach the hair.这些产品不会使头发变白。
• Did you bleach this tablecloth?你把这块桌布漂白了吗？

4 bleaches   

使（颜色）变淡，变白，漂白( bleach的第三人称单数 )

参考例句：

• Oxidation of soils by bleaches can break down large molecules into smaller segments with polar sites. 关于漂白对污垢的氧化作用，使其大分子裂解为带极性基因的短链段。
• Clean up spilled medicines, bleaches and gasoline and other flammable liquids. 清除溢出的药品，漂白剂、汽油和其他易燃易爆液体。

5 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

6 vibrant   

adj.震颤的，响亮的，充满活力的，精力充沛的，(色彩)鲜明的

参考例句：

• He always uses vibrant colours in his paintings. 他在画中总是使用鲜明的色彩。
• She gave a vibrant performance in the leading role in the school play.她在学校表演中生气盎然地扮演了主角。

7 tar   

n.柏油，焦油；vt.涂或浇柏油/焦油于

参考例句：

• The roof was covered with tar.屋顶涂抹了一层沥青。
• We use tar to make roads.我们用沥青铺路。

8 nicotine   

n.(化)尼古丁，烟碱

参考例句：

• Many smokers who are chemically addicted to nicotine cannot cut down easily.许多有尼古丁瘾的抽烟人不容易把烟戒掉。
• Many smokers who are chemically addicted to nicotine cannot cut down easily.许多有尼古丁瘾的抽烟人不容易把烟戒掉。

9 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

10 enamel   

n.珐琅，搪瓷，瓷釉；(牙齿的)珐琅质

参考例句：

• I chipped the enamel on my front tooth when I fell over.我跌倒时门牙的珐琅质碰碎了。
• He collected coloured enamel bowls from Yugoslavia.他藏有来自南斯拉夫的彩色搪瓷碗。

11 bleaching   

漂白法，漂白

参考例句：

• Moderately weathered rock showed more intense bleaching and fissuring in the feldspars. 中等风化岩石则是指长石有更为强烈的变白现象和裂纹现象。
• Bleaching effects are very strong and show on air photos. 退色效应非常强烈，并且反映在航空象片上。

12 penetrate   

v.透(渗)入；刺入，刺穿；洞察，了解

参考例句：

• Western ideas penetrate slowly through the East.西方观念逐渐传入东方。
• The sunshine could not penetrate where the trees were thickest.阳光不能透入树木最浓密的地方。

13 lighter   

n.打火机，点火器；驳船；v.用驳船运送；light的比较级

参考例句：

• The portrait was touched up so as to make it lighter.这张画经过润色，色调明朗了一些。
• The lighter works off the car battery.引燃器利用汽车蓄电池打火。

14 aisle   

n.（教堂、教室、戏院等里的）过道，通道

参考例句：

• The aisle was crammed with people.过道上挤满了人。
• The girl ushered me along the aisle to my seat.引座小姐带领我沿着通道到我的座位上去。

15 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

16 cosmetic   

n.化妆品；adj.化妆用的；装门面的；装饰性的

参考例句：

• These changes are purely cosmetic.这些改变纯粹是装饰门面。
• Laughter is the best cosmetic,so grin and wear it!微笑是最好的化妆品，所以请尽情微笑吧！

17 analyzes   

v.分析( analyze的第三人称单数 )；分解；解释；对…进行心理分析

参考例句：

• This approach analyzes management by studying experience usually through cases. 这个学派通常从实例获得经验，用以分析管理。 来自辞典例句
• The econometrician analyzes statistical data. 经济计量学者要分析统计材料。 来自辞典例句

18 blanch   

v.漂白；使变白；使(植物)不见日光而变白

参考例句：

• We blanch almonds by soaking off their skins in boiling water.我们把杏仁泡在沸水中去皮弄成白色。
• To blanch involves plunging food into boiling water,usually very quickly.漂白是将食物放进开水里，通常非常快。

19 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

20 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。