It is estimated that Americans pay about $600 million a year for tooth whitening.  It is true that your dentist can whiten your teeth but it will cost you about $500-$1000.  If you are looking to get that white smile but don't want to pay the high dentist's office prices, you may want to consider an off the shelf tooth whitening system. 

Off the shelf tooth whitening kits can start for as little as $15.  Of course different whitening systems will take longer to see results.  Likewise tooth whitening results will fade depending on whether or not you have a heavy cigarette, coffee, or red wine habit.

Most whitening agents will used either hydrogen or carbamide peroxide bleach as their active ingredient.  The potency of these bleaches are far less than what your dentist can use, that is why they are more affordable.  At home tooth whitening kits are designed to work on yellowish teeth as opposed to gray teeth (grey teeth are typically the result of something other than external staining). 

5 main warnings for choosing an off the shelf tooth whitening system:

1.    Tooth whitening agents are not going to make your teeth any whiter than they were when you cut your first tooth. 
2.    Tooth whiteners will whiten only natural teeth, not caps, crowns, veneers, fillings or dentures.
3.    Tooth whitening results are not permanent.  The process will need to be repeated about every 6 months
4.    Brush on and strip whitening applicators can leave splotches and miss the nooks and crannies in your teeth.  For most uniform whitening use an application where the whitening agent is put in a tray that forms around your teeth.
5.    Ask your dentist's advice before choosing an at home tooth whitening kit.  He may be able to suggest a type and brand that would work best for your specific whitening concerns.

Minimize your risk
    Do not use a tooth whitening system if you have gum irritation, a deep cavity or a toothache.  Using the whitening agent on these sensitive areas will result in a great deal of pain.
    Be sure to read and follow the instructions for use shown on the product label. Current clinical studies show that home tooth whitening products are not harmful when used as directed.
    Do not use a tooth whitening product for more than 14 days without consulting a dental professional.
    If you experience tooth sensitivity while using a whitening system, try the following:
1.    Cut your use of the whitening system to half of the recommended time (i.e. wear the whitener for 30 minutes instead of 60 minutes).
2.    Discontinue use of the whitener for two or three days, then resume use.
3.    Stop using the whitener and consult a dentist.
    If you've had dental problems, infections or recent work on your teeth, or if you already suffer from tooth sensitivity, you are at a greater risk to have sensitivity and other tooth whitening complications.  If this is your situation, talk to your dental professional before using a tooth whitener.
    If you are pregnant, have mouth or gum disease or have teeth stained by medication, you should not use tooth whiteners.
    In the event of an adverse reaction, stop using the product!!!
    Sometimes it is appropriate to seek medical attention for your adverse reaction.
    Keep the product you were using when you had the adverse reaction.  It is helpful to the medical professional who will be helping you.