Teeth Whitening? good idea?

hey, i was just wondering if teeth whitening is a good idea. and if its not why? thanks.
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I drink way too much coffee and started to get stressed out when they weren't as white anymore. I was going to go the dentist to have him do it but it was ridiculously expensive. So I looked for forever and I finally found a kit that's just like the one the dentist uses with the mold and injection. It works amazing and I'm glad I didn't have the dentist do it. I got it on sale too because they were having a trial where you get to try it for the cost of shipping for like 6 bucks. I don't know if it's still on sale but here's the website. http://mywhiterteeth.info
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