I have a root canal filling in one of my teeth. The tooth is changing color. Can anything be done about it?

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 will change 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 ceramic crown.

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。