In order to fully address all the questions we get about how to whiten teeth, in this article we intend to establish some definitions and differences between current common whitening techniques.
Once this foundation is in place, we can dive into the risks of whitening techniques, how to naturally whiten your teeth, and advanced strategies to have a naturally whiter smile in upcoming articles.
We recently started this discussion with an article focused on what we consider being the first step how to whiten your teeth naturally.
In today’s discussion, let’s dive into understanding how whitening works, the difference between intrinsic and extrinsic tooth discoloration, and common whitening strategies.
The Two Types of Stains
There are two main categories of stains that cause our teeth to be discolored.
Intrinsic stains occur when the deeper layer of tissue, the dentin, becomes discolored.
Common causes of intrinsic stains are:
Dental fluorosis – when a person is exposed to too much fluoride while the teeth were forming
Antibiotic exposure – exposure to tetracycline early in life can cause intrinsic stains
Tooth trauma – if you injure a tooth badly, it can permanently discolor
Extrinsic stains are what most of us think of when we want to whiten our teeth. Extrinsic stains are on/in the surface enamel layer of tissue on our teeth.
To help stop causing extrinsic stains on your teeth, please read about common staining foods in our article, the first step to having naturally whiter teeth.
Honorable mention goes to age-related discoloration.
Teeth tend to yellow as we age. The main reasons for this are accumulated stains and a thinning of enamel. You see, dentin (the layer of tissue in each of our teeth just under the outer enamel layer) naturally has an ‘off white’ color. So if we wear through our enamel more quickly, our teeth will seem more discolored.
After a handful of decades drinking coffee and brushing unconsciously, you can see why teeth yellow with age. If we allow stains to accumulate while we brush our teeth like we were scrubbing a grout line, the combination of extrinsic stains and thinning enamel will hasten results in ‘age related’ discoloration.
As you’ll see in our next articles as we continue to dive into this subject, the good news is there is much we can do to naturally whiten our teeth and not compromise the long-term health of our smiles (yes, even if we consider ourselves in that ‘age related’ group :))
Let’s continue to establish some definitions to base our discussion on…
What’s the difference between ‘whitening’ and ‘bleaching’?
While both terms whitening and bleaching are used for making our teeth whiter, our culture definitely has leaned toward using the term whitening. I’m sure this is at least in part because industry realized that using the term bleaching is bad for marketing such products.
However, there are specific differences.
For the purpose of being able to discuss this clearly, we’ll use whitening when we refer to strategies and techniques that address extrinsic (surface) stains. We will use the term bleaching when referring to strategies and techniques that address intrinsic stains.
Mechanical vs Chemical Strategies
The last distinction we want to put in place is the difference between strategies used to whiten/bleach teeth.
Mechanical methods use abrasives to remove surface/extrinsic stains from the teeth. Common choices here are ingredients like baking soda, clay powders, and hydrated silica.
Chemical methods use various bleaching agents to address both extrinsic and intrinsic stains.
All commercial whitening techniques use chemical bleaching agents to achieve their goal. Whether it’s an at home kit, a professional whitening treatment at your dentist’s office, or even just commercial ‘whitening’ toothpaste, all products and techniques we have reviewed use chemical means for whitening teeth.
These chemical agents work by bleaching the extrinsic stains as well as intrinsic stains by penetrating the teeth and bleaching the dentinal layer of tissue as well.
What are the ingredients in commercial bleaching (whitening) products?
There are currently four main chemical agents used in tooth ‘whitening’ kits/treatments. As you’ll see, they all use the same ‘strategy’, to bring free oxygen to oxidize stains (both extrinsic and intrinsic) from the teeth.
Not coincidentally, you’ll probably recognize most if not all of these chemicals as the ingredients used to bleach (whiten) our laundry.
Hydrogen peroxide has been the ‘go to’ bleaching method for many years. However, over the years, more and more studies have been conducted that show some potential drawbacks of using hydrogen peroxide at the concentrations used in tooth bleaching.
(note to Healthy Mouth System customers: We will thoroughly address the relative risks of using hydrogen peroxide in our upcoming article on the risks associated with tooth whitening methods as well as how to safely use hydrogen peroxide.)
Carbamide peroxide is a solid crystalline form of peroxide created by combining hydrogen peroxide with urea. When carbamide peroxide dissolves in water, it turns into hydrogen peroxide. It’s a different delivery of peroxide that studies seem to suggest has less drawbacks than traditional hydrogen peroxide based bleaching methods.
A main point on concentrations…
The concentration of peroxide (whether hydrogen or carbamide) has a huge impact whether this product is going to be safe or risky to use in the mouth.
When considering the concentration of a peroxide product, the whitening system has to use 3 times the carbamide peroxide to obtain the same amount of hydrogen peroxide. In other words, a 15% solution of carbamide peroxide yields a 5% hydrogen peroxide solution when used.
We will dive much deeper on this subject of concentration in upcoming articles discussing the risks of whitening products.
Chlorine dioxide is considered by some safer than the others above. However, like so many products marketed as ‘new and improved’, why industry began using chlorine dioxide helps to shed light on this confusing subject.
It turns out that the UK had some pretty big concerns about allowing the use of peroxide (either hydrogen or carbamide) to be sold in tooth bleaching products in the UK. So, in an effort to find a ‘workaround’ of the legislation, industry turned to chlorine dioxide (the legislation was clearly written based on the use of peroxides)
More on chlorine dioxide and its relative safety in future articles…
Sodium perborate is a less used chemical for bleaching treatments. Like other strategies above, sodium perborate is another form of bringing ‘free oxygen’ in the form of hydrogen peroxide to sit on the teeth to whiten.
Bringing it all together
Here are a couple of statements to help bring all this information together.
Whitening techniques use mechanical methods to remove extrinsic stains.
Bleaching techniques use chemical methods to remove both extrinsic and intrinsic stains.
(Just remember, the tooth whitening industry has chosen to move away from the term bleaching for the ‘nicer’ term. That still doesn’t change the fact that they use bleaching agents to accomplish their goals.)
Now that we have these terms defined, we can turn our attention to the relative risks of each of these strategies, how to use the strategies more wisely to reduce the risks, as well as strategies to naturally whiten our smiles.
Until the next article in this series, may your bright, healthy smile continue to bless your life and the lives of those around you each and every day!
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