Cosmetic teeth whitening has definitely increased in both popularity and availability so lets explore a little about what it is, how it works and why having a great smile is important.
The history of teeth whitening, or cleaning, can be traced back to 3000 B.C. People used “chew sticks” to clean particles off their teeth, (much the same as you see in the show Survivor).
Race ahead to the 20th century where peroxide was used as an oral antiseptic gel to treat the gums; dentists tried different ways to keep the gel on the gums longer. It became quickly apparent that a side effect of that treatment was that it whitened the teeth. This in turn led to the mass marketing of tooth whitening products of which you see today.
Tooth-enamel discolouration is caused by a variety of things. They include ageing, superficial stains from drinking coffee, coke and wine, smoking, or from taking medications such as tetracycline, diseases and even genetics.
To understand how teeth whitening works we first need to have a tooth anatomy lesson.
OK…so the white part surrounding the top of the tooth is the enamel, the peachy colour just under that is the dentin. This is essentially what gives your tooth it’s colour and this is genetically pre-determined.
Think of the enamel as the window surrounding your tooth, so when we whiten the tooth we are basically “cleaning the windows” to show the true colour of your tooth. If your dentin is more an ivory colour than white then unfortunately you will never have that bright white Hollywood smile unless you invest in veneers. So when you are looking through all those Instagram feeds and you see blindingly white teeth you are either looking at veneers or clever lighting ( IE Photoshop).
Next question, why do our teeth stain? If you could look at your tooth enamel under a powerful microscope, you would see small textures and pores in the mineral crystals. These contours are likely to be even more significant if you’ve struggled with enamel erosion in the past. When dark foods and beverages are introduced to your mouth, the small particles can get trapped in the microscopic pores, causing stains on your teeth.
Using a bleaching agent like hydrogen peroxide or carbamide peroxide essentially works its way through these pores to get to the stains and bleaches them.
The deeper the stains or the darker the staining the more time it takes. Some peoples teeth are naturally more porous than others again, genetics to thank and what this means in a nutshell is, the more porous your teeth the better results generally but the downside is that the tend to stain faster than those will naturally less porous teeth.
Have you ever noticed that as you get older your teeth your teeth look more discoloured? This is due to the fact that as we get older our enamel becomes thinner resulting in more of the dentine showing through, hence yellower looking teeth.
Are there risks associated with teeth whitening?
Absolutely as with anything there is always an element of risk which is why you must choose your provider carefully.
The most common complaint of tooth whitening is sensitivity. This can be due to a few factors. The percentage of hydrogen peroxide used. The higher the percentage the more likely it is you will experience sensitivity. The most common percentage used on cosmetic whitening is 6%-12%. If you are a dentist then you can use 35% +.
Many cosmetic whitening clinics will use a 12% because they can get faster results but that can come at a cost for the client who is left with sensitivity that can be extremely uncomfortable and last for days.
Demineralisation of the enamel was also a concern however after studies it has shown this to be only a problem when using 35% hydrogen peroxide and stronger. ( Link to study will be posted at bottom of blog)
Not every one that wants their teeth whitened is a good candidate and this is where good training comes into its own. Because we are not dentists, cosmetic teeth whitening practitioners must err on the side of caution and refer clients back to their dentist of they are unsure of the suitability of the treatment for the client. A comprehensive consent process must be undertaken to ensure there are no contraindications to treatment.
With more and more teeth whitening clinics popping up the clients must do their due diligence and check the training of the practitioner as some have as little as a couple of hours training that “come with the machine”. It’s a case of buyer beware.
As a practitioner, registered nurse and member of the New Zealand Cosmetic Teeth Whitening Associates I am very strict about who I will take on as a client as it is my responsibility to provide education and safe and effective care.
The best part of my day is when I hand the client the mirror and their face lights up with a beautiful whiter smile. The increased confidence that comes from a brighter smile is not to be underestimated which is why I love what I do, but with this comes great responsibility.