我有一颗牙在牙根管里补过。现在这颗牙变了颜色，有什么办法可以解决?
Sometimes a tooth with a root canal filling willchange color.
牙根管补过的牙有时会变色。
I can treat it by bleaching it with superoxol(30%H2O2).
我可以用30%的过氧化氢液来漂白牙齿。
If the crown of the tooth is weak it would be better to make a porcelain, acrylic, or ceramiccrown.
假如牙冠薄弱，那么还是做上瓷的、透明合成树脂的或者是烤瓷的牙冠。
If the crown of the tooth is strong, I'd rather bleach it. Bleaching a tooth isn't very difficult.
假如牙齿结实的话，还是漂白好。漂白牙齿并不困难。
What is the first step, Doctor?
医生，第一步怎么做?
The first step is to remove all of the old filling.
第一步先把所有的填补物都挖掉。
A rubber dam is needed to prevent the superoxol from burning the gingival.
需要做个橡皮障免得牙龈被烧伤了。
How is the superoxol applied?
怎样使用30%的过氧化氢液?
The Superoxol is applied to the tooth with a little bit of cotton.
可以用小棉球将30%的过氧化氢液涂到牙齿上。
The bleaching is done by applying heat to the tooth with a hot metal dental instrument.
漂白牙齿要用一种发热的金属器械把热送达牙齿上。
There's no discomfort associated with this technique.
进行这种疗法并不会有什么不舒服。
What color does this treatment make the tooth?
治疗完了之后牙齿会变成什么颜色。
The tooth might be a very light color after it's bleached.
牙齿经过漂白之后会变得十分亮，
However, it will change to a normal color in less than one week.
但是到了一个多星期之后就会变得与正常的牙齿颜色一样。
