Teeth whitening was the No. 1 most requested cosmetic service in America according to a 2011 survey by the American Academy of Cosmetic Dentistry.

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We're not born with white teeth.

That might come as a shock to many, because it seems that we spend much of our adult lives trying to "get back" to the blindingly snowy smiles of our youth. In fact, teeth whitening was the No. 1 most requested cosmetic service in America according to a 2011 survey by the American Academy of Cosmetic Dentistry. Yet the fact is that most of us are born with ivory-colored teeth, or a shade known as A2 in dentist-speak -- and A2 teeth are actually seven shades away from pure white, which is designated as B1.

Thanks, in large part, to celebrities who bleach their teeth to artificial whiteness levels (well beyond B1) and then beam their bright whites at us from the silver screen, snow-white smiles are now all the rage -- with people shelling out $1.4 billion in 2006 alone for whitening procedures [source: Mapes].

But beyond celebrity emulation, there also seems to be something hard-wired into us that appreciates a clean and appealing smile. Once again, according to the American Academy of Cosmetic Dentistry: Pretty much all adults (99.7 percent of them at any rate) believe a smile is important as a social asset; 96 percent feel that dingy teeth make you less attractive to the opposite sex; and 74 percent think a sour smile can hurt your chances of having a successful career.

If you feel it's time to turn up the whiteness factor of your teeth, one option would be to seek out procedures -- like laser whitening -- that are done in the dentist's office and range between $500 and $1,000. Another option would be to ask your dentist to set you up with an at-home whitening system (such as a tray and gel), which would take a little longer and cost anywhere from approximately $200 to $500.

But if you're looking to get a million-dollar smile for a lot less than that, there are several at-home options that might just be for you, as we'll discuss next.