Teeth collect superficial stains that result in the outer layer appearing dirty or yellow; these can be polished of easily. Teeth also accumulate stain into the very structure of the tooth and these cannot be easily polished off. But tooth whitening methods can remedy this discoloration. There are natural methods, at home treatments, and laser treatments available.
What causes teeth to discolour?
The enamel of teeth is typically white, or perhaps ’ivory’ in colour. Enamel becomes more translucent with age allowing more of the layer beneath, called ‘dentine’ to shine through. This dentin can vary widely in colour but is naturally a darker tint than enamel. Enamel and dentine are naturally porous allowing stains to seep into the very structure of a tooth over time. For some people this discoloration with age occurs much faster than in others. A higher acid environment in the mouth, for example, as a result of acidic fruits and drinks, leads the enamel of teeth to become more porous increasing the risk that the teeth will discolour at a faster rate.
Other causes of discolouration?
Teeth discoloration can also result from the thinning of the surface (enamel) layer of the teeth with time. When this happens, the layer beneath the enamel called the “dentin” is more easily seen and may even be seen directly. The enamel of teeth is naturally thinner towards the gum line so that it common for teeth to appear yellower or darker towards the gum line.
When is teeth whitening helpful?
With time, coffee, cigarettes, and food stains can seep into the cracks in the enamel and discolor the dentin further. This only serves to darken that yellow hue. Dental cleaning will remove the plaque and the dirt from this enamel layer but that does not actually address the source of the discoloration. This is where teeth whitening comes into play.
How does teeth whitening work?
Teeth whitening uses peroxide groups to react on contact with the enamel. When this happens, it releases free radical oxygen which oxidizes the pigments responsible for making colour, and produces a whiter appearance.
Teeth whitening can be done at a dentist office or at home. This form of treatment varies in terms of the time it takes. Generally, the length of time required is about 1 hour over the course of several days (for at home treatments) or several weeks (for regular clinical treatments). This is also contingent upon the shade you desire as your end product. At its most simple, tooth whitening is a function of time and the concentration of the peroxide. The secret to successful whitening is about holding the peroxide on the tooth surface for sufficient time, in sufficient concentration.
How long does tooth whitening last?
Of course, while the effect bleaching is long lasting, as teeth continue to accumulate stain into their very structure over time, the whitening effect fades. It typically takes many years for teeth to return to their pre-whitening state. Whether using tooth whitening or not, the colour of natural teeth is not static. Having whitened teeth to a desired level, you can extend this lifetime by avoiding staining elements like wine, coffee, tea, or tobacco.
Types of Teeth Whitening
Put simply, tooth whitening can be undertaken In-Surgery by your dentist, or At-Home by you.
In-surgery teeth whitening is a dental procedure whereby your dentist whitens your teeth with, as the name suggests, a strong light source and a peroxide heavy gel. This procedure can be done in a significantly shorter amount of time compared to at home methods, though the cost is higher. This method often creates an abnormally white color which actually results from dryness induced by having the mouth open for the extended time of the treatment. Light energy is shone on the teeth without the production of saliva and when paired with the bleach it results in an extreme whiteness that will lose the glow with the natural return of moisture to the teeth.
Home whitening can be done safely without a dentist because the amount of peroxide contained is lower compared to the professional gels. The key element is to have close fitting custom flexible trays made to enable the peroxide to be held on the tooth surface for the extended periods at the desired concentration. Standard trays supplied with off-the-shelf products are nowhere near as effective as close fitting professionally made trays. They are often clumsy and ill-fitting to the individualized mouth. Investing in a personalized tray can minimize gum irritation and produce more effective results across the whole of your smile. Properly fitting trays are durable and last many, many years and enable very effective tooth whitening to be undertaken any time you need to whiten up for a special event.
There are several off-the-shelf systems:
- Whitening kits which use flexible teeth trays for the application of whitening gels. These kits come with LED to expedite the effect in a similar fashion to that of lasers used by professional dentists.
- Whitening pens are another alternative which contain whitening gel you can apply to your teeth.
- Whitening strips are the simplest to use out of all the products and they are relatively inexpensive.
Are there risks with At-Home teeth whitening?
At-home products is nowhere near as effective as the use of custom fitted tray. There is also an increased chance that the peroxide will irritate your gums or cause tooth sensitivity. These are symptoms that the percentage of peroxide is too high, or that you are whitening your teeth at home too often. Inflammation can occur if the gums have been heavily irritated.
Overall, tooth whitening is an effective companion to regular teeth maintenance and care, one which can afford you a brighter smile for years to come.In-surgery tooth whitening by a dentist is generally preferred to at-home use of whitening kits.
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