Self-treatments using baking soda, ash and hydrogen peroxide provided online with no dental experience, can strip tooth enamel and cause lasting damage to the gums, experts cautioned.

　　專家提醒，網(wǎng)上流傳的用蘇打粉、灰末和過氧化氫進(jìn)行牙齒美白的方法，若沒有牙醫(yī)的指導(dǎo)，會損傷牙釉質(zhì)，給牙齒帶來永久的傷害。

　　The techniques are becoming an increasingly popular alternative to expensive professional treatment, especially among teenage girls.

　　目前這些美白方法廣受歡迎，尤其是受到少女們的追捧，并逐漸取代了昂貴的專業(yè)美白治療。

But dentists said some of the methods can erode the enamel covering of the teeth, making them appear darker rather than whiter.

　　但牙醫(yī)提醒說，有些方法可能會損傷覆蓋在牙齒上的牙釉質(zhì)，反而讓牙齒顯得更黑。

　　Up to 100,000 people undergo some type of teeth whitening treatment each year, ten times more than did so five years ago.

　　近年來，每年進(jìn)行牙齒美白的人數(shù)已經(jīng)達(dá)到10萬人，是五年前的十倍。

　　But for many people the process is prohibitively expensive, costing up to ￡1,300(＄2,096) for laser treatment and as much as ￡700(＄1,128) for professional bleaching.

　　但是對于很多人來說，進(jìn)行專業(yè)牙齒美白的費用太過高昂。激光美白的費用是1300英鎊（約2096美元），專業(yè)牙齒漂白至少需要700英鎊（約1128美元）。

Professor Andrew Eder, clinical director of the London Tooth Whitening Centre, said using baking soda repeatedly would strip the teeth of enamel, leaving them browner and more sensitive, while salt would scratch the enamel and any use of acid was especially damaging.

　　倫敦牙齒美白中心臨床主任安德魯 埃德爾教授表示，反復(fù)使用小蘇打會損害牙釉質(zhì)，牙齒會變得越發(fā)暗沉、敏感；用鹽可能會刮傷牙釉質(zhì)；而使用任何鹽酸美白牙齒帶來的傷害則更大。