Before you go off and spend hundreds of dollars on teeth whitening, I suggest you try good ole fashioned Crest strips.  They work just as well long term.

I had my teeth whitened a few years ago and while I did see immediate results, they went back to what they were before just a few months after.  Not only that, but your teeth feel rough because the whitening strips them of enamel.  You can’t eat ANYTHING with any color for about a week after (coffee included) and it’s claustrophobic as all hell sitting in that chair for a half hour with your mouth spread open.

Never again for me.