Over the past few years, professional teeth whitening has become one of the most commonly requested cosmetic dental treatments in the world. In fact, the industry as a whole has experienced unprecedented growth and by 2025 is likely to be worth somewhere in the region of $7.5 billion.
If you are one of the 62% of Australians who aren’t happy with their teeth and are considering teeth whitening treatments, then it’s understandable that you would want to know the answer to the question how does teeth whitening work?
Before we dive into the mechanics of teeth whitening, it’s important to understand why teeth become stained and jaded in the first place.
Let’s take a look…
Whitening Treatments – The Science Of Tooth Staining
Teeth become discoloured for several reasons and result in both intrinsic (deep) staining and extrinsic (surface) staining.
Extrinsic staining is most commonly attributed to discolouration caused by factors such as food intake (particularly highly pigmented foods like coffee, curry and tomato sauce) and smoking. This is the easiest type of staining to remove.
Intrinsic staining on the other hand. is harder to shift and is typically caused by ageing, genetics and even, certain antibiotics.
All staining, irrespective of whether it is deep or superficial, is composed of chromogens. These are colourless chemical compounds that have the potential to become highly pigmented.
As these compounds stick to the tooth enamel or accumulate inside the tooth, they collect pigments from food, tobacco smoke or discolouration from certain medications (antibiotics). This is what causes teeth to stain.
The science behind a whiter smile
When it comes to teeth whitening, there is also another factor that needs to be taken into consideration and that’s the potential to achieve the whitest smile.
Unfortunately, the whiteness of a person’s smile has more to do with genetics than luck. You see, when it comes to teeth, there is no such thing as natural white. It’s true!
Instead, all teeth have an underlying colour or shade that ranges from reddish-brown and reddish-yellow through to reddish-grey and even grey.
Believe it or not, the average tooth colour shade is A3 (consisting of a slight yellow/red tint). Most people, however, tend to accept this as ‘white’ because they are familiar with its appearance and automatically associate it with a beautiful natural-looking smile.
To achieve the actual shade of white, a patient would need to whiten their teeth to a shade beyond B1 which gives the appearance of a ‘Hollywood smile’.
To most people. this type of smile appears fake and unnatural.
In truth, anyone looking for a more natural smile enhancement should only need to lighten their teeth by just 2-3 shades. For most people, this is enough to make a huge amount of difference.
The Science Of Oxidation Teeth Whitening
Now that you understand what teeth staining is, how it forms and how your natural tooth colour works, we can finally get to the part where we answer the question how does teeth whitening work?
The answer lies in the oxidation process…
Without getting into too much detail, oxidation is an essential part of what chemists call a redox reaction. In a redox reaction, chemical compounds that are oxidised, lose electrons. The process of rust, for example, is a good example of a redox reaction.
So, when it comes to teeth whitening, one of two chemical compounds are used.
- Carbamide peroxide or
- Hydrogen peroxide
Hydrogen peroxide is the bleaching agent while carbamide peroxide breaks down into a combination of hydrogen peroxide and urea when applied to the teeth.
Teeth whitening treatment works because when either hydrogen peroxide or carbamide peroxide is applied to the teeth it can penetrate the porous tooth enamel and cause an oxidation process on the stain chromogens. This process breaks down any chemical bonds in the chromosomes (electrons) causing the pigments to break into tiny, microscopic fragments, scattering them. Once scattered, it gives the illusion of a brighter whiter smile.
This in effect is how teeth whitening works…
So What’s The Difference Between Professional Teeth Whitening And Over-The-Counter Whitening Treatments?
The answer lies in the strength of the hydrogen peroxide (the bleaching agent). The stronger the peroxide, the quicker the results.
Typically in Australia, over-the-counter teeth whitening products are only permitted to contain up to 6% hydrogen peroxide. On the contrary, because professional teeth whitening treatments such as take-home trays and even more so, chair-side teeth whitening are dentist-led, they usually contain around 35% hydrogen peroxide.
In the case of chairside teeth whitening treatments patients can expect to see a noticeable difference in as little as 1 hour whereas take-home whitening kits can take 7-10 days to produce noticeable results. Moreover, despite their added strength, dentist-led whitening treatments are safe and effective.
Are you ready to experience the science behind a brighter whiter smile?
If so, come and talk to our Southpoint Park Dental team about professional teeth whitening. We can help you to achieve the whiter smile you deserve!
Call us on (07) 5655 7688 or book a smile consultation online today.
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