Someone who gets tooth stains may want a whitening toothpaste .

一些人牙齿染色的人可能需要增白牙膏。

Whitening toothpastes will remove only surface stains , such as those caused by smoking , tea or coffee .

增白牙膏将可以去除牙齿表面色斑，比如由吸烟，喝茶或咖啡引起来的。

Some kind of whitening agent : sometimes these are variations on hydrogen peroxide , which are toxic when ingested .

一些增白剂：有时候增白剂是过氧化氢的变体，如果被吞食是有毒性的。

People have gone hog wild for whitening pastes , and there is concern about their longterm safety , by dentists in particular .

人们对增白牙膏趋之若鹜，关于它的长期安全性，常有担忧，尤其是牙医们。

Faced with a entire aisle full of toothpaste options-one whitening , one brightening , one with extra sensitivity , and one with extra fluoride and baking soda ingredients-their eyes glaze over and they stare , circuit-fried and numb , unable to choose or buy anything .

光是牙膏就有整整一排，增白的、提亮的、抗过敏的、含氟和小苏打的他们呆呆地瞪着，像被电击了一样愣在那里，无从挑选。