How does teeth whitening work?
This is covered briefly in our Cosmetic Dentistry section, but here we will go into more detail of
the specific chemicals, processes, and interactions with your teeth that occur during a standard
teeth whitening procedure.
There are two main choices you have when choosing to get your teeth whitened. You can do it
at home, or have it done professionally by a dentist. Athome treatments come in three forms:
1. Semiopaque strips that stick to the teeth
2. Whitening trays filled with a cleaning solution
3. Brush on gels
There are some advantages to doing it yourself at home, such as decreased cost, or not having
to schedule an appointment during your busy week. But there are some disadvantages as well.
The amount of time you have to spend to get the same level of whitening done professionally
add up pretty quickly. The athome whitening procedures range from a week of use to a month
of use, and beyond. If you aren’t looking to add one more thing to your daily regimen, then
getting the job done at a dentists office is a wise choice.
Now let us discuss the typical chemical mixtures that are used in teeth whitening, both in at-
home treatments, and in those performed in dental offices. Hydrogen peroxide is the basis of
chemicals that are used to clean teeth. This is because it is chemically unstable and readily
produces reactive oxygen. When this oxygen is released in an oxidizing form it targets the
particles on the surface of the teeth that are the cause of staining or yellowing. Carbamide
peroxide operates under the same concept except for the addition of urea(carbamide). This
addition allows the peroxide to oxidize longer on the surface of the teeth. The longer the
peroxide is on the teeth, the better job it can do in attacking the cause of discoloration.
The reason this peroxide doesn’t hurt your teeth is because your enamel is essentially
composed of a layer of hardened minerals. These minerals cannot be affected by the peroxide.
But within that structure of minerals there are organic compounds which are susceptible to
staining. The peroxide targets those compounds, in effect, bleaching them so that they no
longer have any pigment. This lack of pigment is the magic behind teeth whitening.
● The strips have a gel on them which contains 10% carbamide peroxide gel or less
● The active ingredient that does all of the whitening in a tray system is usually a 616%
solution of carbamide peroxide in a gel form (approximately equal to 3.47% hydrogen
● The brush on gels use the same chemical in about a 6% solution
● Dental offices typically use a solution of 35%45% hydrogen peroxide
● They reason they don’t use carbamide peroxide is that along with the hydrogen peroxide
mixture, they use either heat, UV light, or both to enable the peroxide to work longer at
targeting aforementioned organic compounds within the enamel of your teeth.