Before we get down to the nuts and bolts of how teeth whitening works, we really should take some time to talk about the enemy – stains!
The fact is that unless you live on a diet of water and lettuce, it’s highly likely that you will develop some kind of teeth staining over a period of time.
Every time you put stain-inducing foods or beverages in your mouth – and there are a lot of them – chemical compounds such as chromogens and tannins (the same chemicals that give them their distinctive strong colour) will collect on the surface of the teeth. Over time, it forms a new layer known as a pellicle film over the top of your tooth enamel. This in effect is tooth staining in action!
While regular brushing can eradicate some staining, when the pellicle layer remains on the tooth’s surface, some of that staining will penetrate down into your tooth enamel via microscopic pores. Once stains penetrate below the tooth surface, they simply can’t be scrubbed or brushed away. As such, the only real way to remove them is via a process known as cosmetic teeth whitening.
There are of course several ways to whiten teeth, but for the purposes of this article, we’re going to be talking about professional teeth whitening – The kind that you would talk to your dentist about – rather than buying one of the thousands of over-the-counter products.
Professional teeth whitening – The in’s and out’s.
Most professional tooth whitening brands utilize one of two whitening or bleaching agents. These are carbamide peroxide or hydrogen peroxide (the same substance that bleaches hair).
When a patient undergoes dentist-supervised teeth whitening they’ll be exposed to controlled but relatively high strengths of either carbamide or hydrogen peroxide. More than can be legally supplied over-the-counter.
Treatments can be administered either chair-side in the dental clinic or given to you in kit form to use in the comfort of your own home. Either way, they’re carefully controlled by your dentist and should, therefore, be safe.
As a general rule of thumb, dentists offering chairside teeth whitening tend to use hydrogen peroxide gels of around 15-35% bleaching strength. Take-home systems supplied by your dentists will typically contain 10-20% carbamide peroxide and will often include sodium fluoride to soothe any sensitivity.
Teeth whitening chemistry
Both hydrogen and carbamide peroxide has been proven to be extremely efficient at lifting tooth stains but how is this achieved?
Time for some chemistry…
Firstly, it’s worth pointing out that when carbamide peroxide is mixed with water (in this case saliva) it releases hydrogen peroxide elements anyway. For this reason, most chairside treatments will utilise hydrogen peroxide as their main source of teeth whitening. This kind of makes sense as it skips a process.
Once the hydrogen peroxide is applied to the teeth it breaks down and forms what are known as free radicals. Sometimes a special activating light is used to aid the process.
Free radicals are, in this instance, organic, stain-busting molecules that penetrate through the pores of the tooth enamel and break down the bonding agents that hold the stain together.
Once the stain has been broken up, the same molecules then oxidise the chromogens or tannins (the chemical compounds that give off a strong colour) causing those compounds to become significantly lighter in colour. Hey presto, you have whiter, brighter teeth!
Of course, applying a powerful chemical to your mouth may sound somewhat alarming but, manufacturers work hard to ensure their tooth products are both safe and have a neutral pH level. Because of these factors, side effects – if any – are usually reduced to mild temporary tooth sensitivity.
The good news is that thanks to some clever chemistry and the skill of an experienced dentist, you can enjoy a whiter, brighter smile with professional chairside teeth whitening in as little as one hour.
It’s worth pointing out that typically, teeth will continue to whiten for up to a week after a chairside whitening session. So while patients should see a difference immediately, whitening will continue to improve over the coming days.
So that’s chairside teeth whitening covered…
What about take-home teeth whitening – how does that work?
So you want to know how take-home teeth whitening kits work.
In reality, the chemical process works in pretty much the same way. The only real difference is that carbamide peroxide is usually the bleaching agent of choice and generally, it’s of lower strength. This means that patients can expect a whiter, brighter smile in a few weeks rather than a few days.
As opposed to a whitening application painted directly onto the teeth by your dentist (as in a chairside whitening treatment) your dentist will make custom-made trays. These are designed to fit your teeth exactly and are filled by you with a designated amount of whitening agent.
Trays are then worn over the teeth (either a few hours a day or overnight) in the comfort of your own home. Once worn for the allotted time, the trays are removed, and the teeth are rinsed off. The process is continually repeated the next day/night until eventually, the right degree of whiteness has been reached.
So there you have it…how teeth whitening works!
If you would like to find out more about the teeth whitening process or you would like to book a chairside whitening treatment, don’t hesitate to contact the team at Infinity Dental Care on 02 9159 6237. We guarantee that you are in safe and trusted hands.