How Do Tooth Whitening Treatments Work?

We associate a beautiful smile with good oral health—and pearly, bright whites are one of the first measures we look for. Whatever differences we have in body types, fashions and so forth, the desire for a bright smile is universal, which is why tooth whitening is so popular around the world. And its popularity continues to grow.  

 

There are innumerable products and methods, from home-based boxes to treatments that need to be performed in a professional setting. You have the luxury of choosing the one that best suits your budget and preference. 

 

But, did you ever wonder how some of these whitening treatments work? Read on to find out! 

What parts of the tooth are affected during tooth whitening procedures? 

 

Most tooth whitening procedures use materials that contain hydrogen peroxide and carbamide peroxide as active ingredients. The mechanism of each is basically the same—more commonly, we call it bleaching. 
The part of the tooth you see and feel is your enamel, which represents only the outermost layer of your teeth above your gums. It’s the hardest substance in your body, but isn’t without weaknesses or the possibility of corrosion. Enamel appears white, yet in reality is translucent.  

 

The layers of tooth right below enamel is comprised of dentin, and its natural color is a soft yellow. As you age, dentin tends to become darker, and your enamel begins to appear blurry. No matter how diligent you are in your tooth brushing and oral hygiene, your teeth will naturally change color over time.  

 

That said, stellar oral hygiene is the best way to combat this natural effect. But if push comes to shove, there are these whitening options to consider.  

 

Here’s where teeth whitening steps in: 

 

About 20 years ago, it was discovered that applying products with 10% active ingredient carbamide peroxide permeates through the enamel and decomposes the discoloration of the dentin beneath, while also clearing the enamel back to its earlier translucent shine. When carbamide peroxide is kept in contact with the tooth long enough, voila! You can whiten it from beneath the enamel itself. The longer the contact, the whiter the tooth becomes, sometimes until there is nothing left to bleach.  

 

Note that redundant bleaching can carry negative side-effects, like initiating the very decomposition of enamel, so start with a consultation with your dentist to establish what whitening regimen makes sense for you. 

 

Due to high concentrations of hydrogen peroxide or carbamide peroxide in these “bleaching” products, your gums are protected during treatments with cofferdam, or a gel called opaldam. Whitening gel is then applied to your teeth and can be activated by light, heat or chemicals. 
Limitations of tooth whitening 
Be sure to note that no tooth whitening treatment is everlasting, and in some cases teeth can only be whitened so many shades. For a full consultation of the product that’s right for you, and its possible longevity, talk to your dentist.  

 

Another interesting tooth whitening fact is that black or brown discolorations from cavities cannot be removed—these need to be drilled and filled. And, for that matter, bleaching doesn’t work on fillings, so the degree to which you whiten might also have to do with how white the fillings are that you’re working around! Of course, you can always take out old fillings and replace them with whiter ones, too. 

 

The options are many, which makes it all the more important to start with a consultation with your dentist.