Whitening

People have long wanted to have white teeth, which led to tooth whitening attempts a few hundred years ago. At that time teeth were whitened with harmful agents such as urine or acids. There are now good, pH-neutral products that, when used properly, do not damage the teeth or cause other side effects. This is a modern method against tooth discoloration Whitening.

What is whitening?

At Whitening (English "to bleach") is a method of whitening human teeth. Teeth whitening is usually done for aesthetic and cosmetic reasons.

As a rule, it is the patient's ideal of beauty that provides the motivation for teeth whitening. From a medical point of view, bleaching is usually only necessary if the tooth discoloration is stressful for the patient on a psychological level. In the case of tooth discoloration, coloring substances are deposited in the tooth enamel and dentin.

This discoloration can no longer be removed with a simple tooth cleaning, which is why bleaching is often the only way to whiten teeth. It is important that a dental check-up for damage to teeth and gums and, if possible, professional teeth cleaning is carried out before a whitening treatment.

Function, effect & goals

Whitening can be done in different ways. In general, preparations with hydrogen peroxide are used here. These penetrate the tooth and split off the oxygen radicals there.

Oxygen radicals can influence the dyes in the tooth in such a way that they can no longer be recognized. It is important that the whitening agents have a neutral pH value to prevent roughening of the teeth and thus renewed discoloration. The following methods are used for bleaching:

1. Whitening through individually made aligners ("home bleaching") With this method, a splint is made from an impression of the teeth before the actual bleaching treatment. The splint is usually made of plastic and is precisely tailored to the patient's teeth. A peroxide-containing whitening gel is applied to the splint, the splint then covers the teeth. The concentration of peroxide in home bleaching is usually 10 to 20 percent. Depending on the initial color of the teeth and the concentration of the gel, the patient has to wear the splints for between 1 and 8 hours. Depending on the degree of discoloration, 5 to 7 treatments (e.g. for age discoloration) or more than 15 treatments (e.g. for discoloration due to tetracyclines) are sometimes necessary. If the entire dental arch is to be lightened, home bleaching is particularly suitable.

2. Lightening through direct application ("in-office bleaching" or "power bleaching") With so-called power whitening, the concentration of the whitening gel is usually higher than with home whitening. Treatment is therefore carried out directly at the dentist. In preparation, the gums are protected with the help of a rubber dam (rubber-like coating) or another flowable material. The whitening agent is then applied directly to the teeth and can act there. With whitening lamps, more intense results can be achieved through light irradiation, if special gels are applied that can be activated under UV light. The gel is then usually removed after 15 to 45 minutes. Usually one or two more treatments are necessary for the first treatment until the desired degree of lightening is achieved. Power bleaching is mostly used when only individual teeth that are still alive are to be whitened.

3. Whitening through tooth inlays ("walking bleach technique") The walking bleach technique is mostly used when only individual (mostly dead) teeth are to be whitened. The tooth crown is opened and a suitable insert is placed in the tooth cavity. The whitening agent usually stays in the tooth for a few days, which is then closed with a temporary. After the lightening agent has been removed, the crown is permanently sealed. With this method, the whitening is always delayed, as it takes a few days for the peroxide to work its way through the tooth enamel inside the tooth. It is possible to carry out another treatment if the desired degree of lightening has not been achieved. For this reason, many dentists only close the crown when the result is what the patient wants.

In general, it applies to all methods that the teeth do not remain permanently whitened. As a rule, however, the result remains for a few years, but this also depends on the quantity and quality of oral hygiene and the patient's consumption habits (e.g. coffee, tea, smoking). The bleaching has to be repeated when the teeth are noticeably darkened. These so-called refreshing treatments are usually much more gentle on the teeth, as the amount of peroxide no longer has to be selected so high.

Bleaching is always used when unsightly tooth discoloration is to disappear. These usually arise from the consumption of coloring foods such as tea, coffee, juices, red wine or tobacco smoke. But also due to medication, accidents, tooth decay, as well as malnutrition and the death of the tooth pulp, teeth can be discolored.

If whitening is carried out, the colors of tooth fillings, bridges or crowns do not change. Especially in the visible area, fillings, crowns or bridges and veneers usually have to be renewed after bleaching and adapted to the new color. The problem here is the amount of costs that can arise as a result, because tooth whitening is not permanent and with each refresh treatment it can happen that bridges, crowns, fillings and veneers have to be renewed. The dentist should therefore always have an informative discussion with the patient about the effects and costs of bleaching before treatment, as the costs are not covered by the statutory health insurance.

Risks, side effects & dangers

Through the WhiteningTreatment, the patient may experience some side effects. The first often show up during the treatment in the form of a painful sensitivity reaction to the bleach.

In addition, teeth that have just been treated are usually sensitive to sweet and sour food, as well as cold and warmth. In general, however, these sensations are only temporary and often disappear within a few days. It is important that all whitening agents are pH-neutral, since if the pH value is too low, the surface of the tooth substance can be roughened. If the whitening is carried out professionally and with appropriate preparations, whitening can even protect against tooth decay.

However, bleaching can remove minerals from the teeth and thereby weaken the protective layer of the tooth, at least temporarily, which in certain circumstances can also result in covering white spots. However, these also disappear within a few days after the treatment, which can be supported with the help of a special gel. In any case, patients should always bear in mind that bleaching can weaken the tooth structure and, as a result, make the tooth fragile. Irritation of the mucous membrane must also be expected if the whitening agent comes into contact with the oral mucous membrane.

In the meantime, there are research results that show that bleaching can damage the tooth surface. It is also assumed that around 25 percent of the gel is swallowed during bleaching, which can damage the mouth and throat as well as the stomach. However, these estimates relate to home use. In the meantime there are also products for teeth whitening in the free trade (e.g. for brushing on or adhesive strips).

Since these products have different quality features, some products can under certain circumstances lead to lasting tooth damage or insufficient and uneven whitening. In addition, a preliminary diagnosis is missing here, because as a layman it is difficult to assess the causes of the tooth discoloration. As a result, more serious damage to teeth may be overlooked (e.g. tooth decay, inflammation of the roots). For this reason, a dentist should always be consulted beforehand so that any necessary treatments can be carried out.