Teeth whitening is a method of removing stains that have built up on the teeth because of eating or other habits, and it makes your smile brighter. Whitening is the cosmetic procedure dentists perform most often, because it makes a noticeable difference to the look of your smile. It is not a one-off procedure: it needs to be refreshed from time to time to keep the result for longer.
Why do teeth become stained?
The outer, visible part of the teeth is covered by a layer of mineralised hard tissue – tooth enamel. The natural colour of teeth comes from the light that falls on them and is reflected and scattered. How this light behaves depends on the smoothness of the enamel, its thickness and how much the layer of dentine beneath it shows through. Every day, a layer of proteins (the pellicle) forms on the surface of the teeth and is stained by food. In addition, the enamel itself has pores that hold on to stains. Because of these factors, tooth colour differs from person to person and changes with age.
The most common causes of darkened and yellowed teeth are:
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Smoking cigarettes;
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Dark-coloured drinks – coffee, cola, tea, red wine;
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Not taking enough care of your teeth;
You can read more in the article 5 foods that stain your teeth
With age, teeth become less white, because the enamel gets thinner and the dentine that shows through it darkens.
Stains can also form inside the teeth. For example, they can be seen in patients who took more than the recommended dose of fluoride as children. Another example is staining caused by tetracycline antibiotics taken by the mother in the second half of pregnancy, or by children under 8 years of age while their permanent teeth are forming. Injuries to the teeth can also cause internal stains.
Whitening methods are most effective for surface stains.
Preparation before whitening
Other dental problems can affect teeth whitening. If you have tooth decay, it needs to be treated before whitening, because the whitening gel can penetrate deep into the tooth. If your gums have receded, the visible part of the root will look more yellow and will not respond to whitening. Whitening gel cannot change the colour of fillings, ceramic crowns or veneers.
Before whitening, the teeth are cleaned to remove plaque, food debris and tartar.
Types of whitening
There are two main types of whitening: vital and non-vital. Vital whitening is done on teeth with a living nerve, and non-vital whitening on teeth whose nerve is no longer alive.
What solutions do we offer at iSmile Dental Clinic?
In our everyday practice we see patients who would like their teeth whitened, and we offer them all types of whitening procedures, with excellent results and the utmost care for their teeth.
Vital whitening
Whitening living teeth aims to remove stains and discolouration from the surface and to lighten the colour by several shades. We use two main methods: home whitening and in-clinic whitening.
Before whitening, we get to know your oral health through a thorough dental examination. You take an active part in your treatment: you can ask questions and receive explanations and information, and then we move on to the procedure. If we find any tooth decay, it must be treated first.
Build-ups, fillings, veneers and crowns in the smile area will not change colour under the whitening gel. We need to discuss the risk that they may look noticeably darker after the procedure and may need to be replaced.
A professional oral hygiene session is carried out, which includes removing plaque and tartar with ultrasound and polishing. Cracks and defects in the enamel, as well as a large number of fillings, can cause short-term sensitivity during and after whitening, and we warn our patients about this.
Home whitening
For home whitening we offer an Opalescence kit with 4 syringes of whitening gel containing 16% carbamide peroxide. The kit also includes a special whitening toothpaste. We take impressions of your upper and lower jaws. These are sent to a dental laboratory, where custom-made trays are produced.
Your starting tooth shade is recorded so that the result can be compared, and you are given instructions on how to use the gel at home.
You put the gel in the trays and wear them overnight while you sleep. How long the treatment takes depends on the starting colour and structure of your teeth and on how long you wear the trays (on average 8 hours a day). The gel is applied every evening, but we may change the schedule if you have tooth sensitivity. After the whitening is finished, we wait between two weeks and one month before assessing the final result, because the colour still changes somewhat during this time. If your teeth become sensitive during whitening, we prescribe a professional high-concentration fluoride product for extra protection. The result is a brilliant smile.
Advantages of the method:
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The gel has a lower concentration of the active ingredient and is less likely to cause temporary tooth sensitivity;
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The custom-made trays can be used again later to refresh the result;
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The custom-made trays can also be used to apply other products – fluoride or remineralising ones;
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The result is reached more slowly, and you can control it until you achieve the effect you want.
Disadvantages:
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It takes longer;
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Some patients find sleeping with trays uncomfortable;
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You put the gel in the trays yourself, which some patients find difficult. If more gel is used than needed, some of it may reach the gums and cause pain.
In-clinic whitening
At iSmile Dental Clinic we carry out in-clinic whitening with the Opalescence BOOST PF system, with 40% hydrogen peroxide as the active ingredient. This type of whitening does not require impressions. The procedure is done in a single visit to the clinic. The lips and cheeks are isolated, and a special material is applied to protect the gums from the gel. The teeth, which have already been cleaned and polished, are dried and covered with the whitening gel. The gel works actively for 20 minutes on the front surfaces of the upper and lower teeth. The gel is then carefully removed and the change in tooth colour is checked. If needed, and if you would like an even brighter smile, 2–3 applications of 20 minutes each can be done in a single visit to the dental clinic. Tooth sensitivity may occur during whitening, but it will pass. We always warn our patients about this possibility. This way we make sure you feel at ease, and it makes our work more pleasant too.
Advantages of the method:
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The desired effect is reached much faster than with home whitening – within a single visit to the dental clinic;
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No impressions of the teeth are needed, which some patients find unpleasant;
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Lower risk of the gel reaching the gums and causing irritation, thanks to better isolation and control by the dentist;
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You can take an active part in the procedure by saying what you would like, and the dentist has more control over the result – giving you peace of mind.
Disadvantages:
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The gel contains a higher percentage of the active ingredient than home whitening gel, which may cause more temporary sensitivity;
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It is a more expensive procedure.
Non-vital whitening
This is the name for whitening teeth whose nerve is no longer alive. After the nerve has been removed, the tooth takes on a different shade – pinkish, greyish or brownish – and looks different from the vital teeth. When this happens to a tooth in the smile area, its colour can be changed in two ways: by covering it with a crown or by whitening it. Applying whitening gel to the surface has no effect in this case; the gel needs to be placed deep inside the tooth. The filling placed after the root canal treatment is removed, and Opalescence Quick 45% carbamide peroxide whitening gel is placed inside the tooth under a temporary filling for 2 days. At the next appointment we assess whether the gel needs to be placed again. Once the desired colour is reached, a permanent filling is placed.
During home whitening, and after home or in-clinic whitening, you need to follow a "white diet" for one month. During this period you must avoid coloured drinks – coffee, tea, cocoa, wine, coloured natural juices and dark fizzy drinks – and foods containing tomatoes, blueberries or chocolate. During this time your teeth stain more easily.
If you follow your dentist's instructions, the whitening effect lasts about 24 months. If your diet does not include the most common and strongest staining agents, such as coffee, smoking, red wine, chocolate and cocoa, your smile will stay white even longer. After this period, you can have a top-up whitening – in the clinic or at home – which is often shorter than the first whitening.
Side effects and risks
No negative effects of whitening procedures have been established. Sensitivity may occur while the gel is working. It is felt as a sharp pain, and how strong it is depends on your individual pain threshold. The likelihood of sensitivity can be predicted at your first examination, and you will be warned about the risks. The pain gradually decreases and disappears completely within anything from a few hours to a few days.
Frequently asked questions
Does whitening damage tooth enamel?
The procedure does not harm the enamel. The gel penetrates the pores of the enamel and removes the stains that have built up there. Over time, coloured organic matter collects in the pores again, which is why the procedure needs to be repeated from time to time. The strength of the enamel does not change. There is no loss of mineral content.
Can whitening cause tooth decay?
The strength of the enamel does not change. Whitened teeth are just as likely to develop tooth decay as teeth that have not been whitened, and this depends on your oral hygiene, diet and other individual factors.
Do I need to care for my whitened teeth differently?
If whitening causes sensitivity, it is a good idea to use a toothpaste for sensitive teeth until it passes. Following the white diet for the recommended period is also very important. Your teeth should be cleaned regularly.
Can any dentist offer me whitening?
Most dentists offer these procedures. Different manufacturers of whitening products give different instructions for their use. The procedures described here are for Opalescence products, which we have chosen to work with at iSmile Dental Clinic. The reason is that we are confident they deliver the desired results, and this confidence is based on our clinical experience.
This article is for information only and does not replace an examination by a dentist.
