If you have stains on your teeth you may not get the results you want! I'm a dental assistant student and I'll be graduating in August of 09. We're studying bleaching right now, my teacher has been preaching that there are a few different things you need to know. First of all staining is bad, chances are their not going to change however there is a chance they might just depends. Second of all if you have composite fillings on you front teeth bottom or top then they WILL NOT change colors, also if you have cavities bleaching isn't going to do anything good for these. Maybe you should look a little more into this whole bleaching thing, chances are you are not going to get the results you are looking for. This is just advice you are more than welcome to do what you want but you should take these things into consideration