Bleaching for teeth

Synonym

teeth whitening, bleaching English: bleaching

Definition

Bleaching is the artificial lightening of the tooth surface through various technical and chemical processes. Discoloured teeth thus regain a radiant white.

Causes of tooth discoloration

The older a tooth gets, the longer it is exposed to external influences such as colouring food. A tooth therefore undergoes a natural darkening process. This darkening process can be accelerated by food and drinks.

For example, frequent drinking of coffee and tea discolours the teeth. Smoking also darkens the teeth. But teeth can also be discoloured by caries and tooth inflammation.

The colour of the teeth is then usually yellowish-brownish. As a rule, all teeth of the dentition change colour in the same way, so that a discolouration is not noticeable to the observer at first. Only by comparing the colour with the natural tooth colour (e.g. by placing a sample colour palette next to the tooth) does the severity of the discolouration become clear. Furthermore, discolouration can also occur when the tooth pulp dies off (e.g. in case of nerve inflammation and subsequent root canal treatment). In most cases, however, the resulting discoloration is not visible in the entire dentition, but only on the affected tooth.

Bleaching Products

In many cases a hydrogen peroxide base is used for bleaching. Hydrogen peroxide molecules can penetrate the tooth structure (enamel and dentine) and release oxygen radicals. Radicals are molecules which are very reactive and quickly form a bond with other molecules.

The oxygen radicals released in the tooth substance tend to react chemically with colour particles. The consequence of this chemical reaction is that the properties of these particles are changed and they therefore appear colourless. In the dental practice, much higher doses of tooth whitening products are used.

As they are particularly corrosive to the gums and the oral mucosa, they may only be applied by the dentist himself or by his trained specialist staff. Most of these products are applied to the tooth and then irradiated with short-wave light. This intensifies the brightening effect.

There are several products that whiten the teeth, the simplest of which can be applied by the patient himself at home. The variety of the bleaching products offered can be seen in the following overview:In addition to the dentist’s bleaching, there are also bleaching kits available for free sale. The principle is comparable to the dentist’s kit, the concentration of hydrogen peroxide is variable, which is much lower with the over-the-counter bleaching kits.

The set also includes a plastic splint for the upper and lower jaws, but these are not individually made and may therefore not fit well or at all. The danger here is that the splint closes so badly that the gums come into contact with the hydrogen peroxide preparation and are irritated or injured. Special care must therefore be taken when applying the splint.

In order to use a suitable preparation individually, an agreement with the treating dentist can clarify the situation and reduce the risk of complications. Handling: strips are glued to the front of the teeth. Remark: Complicated handling of the plastic strips and therefore they seem to be less suitable for home use.

Handling: Gels are brushed on Every offered bleaching gel works in principle in the same way, they only differ in the concentration of hydrogen peroxide (H2o2). Because of the different hydrogen peroxide concentration the bleaching gels are divided into two main groups: Bleaching gels are offered for home use, which have an oxidative or reductive effect on the colour particles within the tooth substance. This means that the gel either releases or absorbs oxygen.

In general, an oxidative bleaching gel has a stronger and longer lasting effect on the teeth, it works more effectively. The user can apply the gel to the teeth on his own and decide how often the procedure is repeated. Since the chemical processes of teeth whitening take time, the gel should be allowed to work for a few hours before it can be brushed off.

In order to avoid damage to the gums and/or the oral mucosa, it is recommended to place a splint made in the dental laboratory over the teeth. In the dental practice, much higher doses of bleaching products are used. The high concentration of hydrogen peroxide in the gel ensures that the product has a highly corrosive effect on the tissue around the tooth.

For this reason, it should only be applied by a dentist or his specialist staff. In addition, a laser or light source is often used to enhance the whitening effect of the bleaching gel. – One is for use at home

  • The other may only be used in the dental surgery by trained personnel.

Handling: Different felt-tip pens – similar whitening pens. The teeth are “painted”. Remark: The whitening pens all perform well in relevant tests.

A bleaching pen is a whitening product that can also be used on the go. The shape and size of the pencil is reminiscent of a lipstick, which is why it fits in every handbag or trouser pocket. The structure of the pencil consists of an applicator brush and a reservoir containing a gel containing hydrogen peroxide.

The concentration of the bleach is 0.1%, which is why it is freely available for sale and falls under cosmetic products. To use the pencil, not even the teeth need to be cleaned beforehand. They are simply dried with a handkerchief so that the gel can be applied with the pen.

Only when the gel has dried may the lips be closed again so that the hydrogen peroxide does not come into contact with the gums and damage them. After application, the mouth should be rinsed. Handling: Bleaching product is filled into the tray.

Remark: The splints impress by their easy application and comparatively good results. They perform best in the tests. The splint is individually made of plastic in a dental laboratory and is optimally adapted by taking impressions and making plaster models.

A hydrogen peroxide preparation in gel form is inserted into these splints and applied to the teeth. After a certain period of exposure strictly according to the dentist’s instructions, the teeth can be whitened permanently. Care should be taken to ensure that the hydrogen peroxide does not come into contact with the gums, as it damages them.

After inserting the splint, any excess should be removed quickly. The recommended use with the splint is about 1 – 2 times a year and should not be done more often in order not to damage the teeth. If the application is carried out more often, the teeth can become very sensitive to pain and cause discomfort due to cold stimuli, which did not cause any discomfort before the treatment.

There are some bleaching toothpastes on the market that promise to whiten the teeth. But how gently can a toothpaste whiten the teeth? The mechanism of all whitening toothpastes is to remove the upper layer of discolouration by a certain particle size, thus whitening the teeth.

The problem is often that the particles in the toothpaste are so large that they not only remove the discolouration but also the enamel, thus weakening the tooth. If this toothpaste is used too often, the enamel layer becomes thinner and thinner and the teeth become sensitive. The sensitivity of the teeth increases as the protective layer in the form of enamel is removed and the dentine layer comes to the surface.

To avoid this, when buying toothpastes, you should pay attention to the RDA value, which indicates the particle size within the toothpaste. Unfortunately, very few manufacturers nowadays indicate the RDA value on the packaging. Internet research and consultation with the dentist can help in this case.

A value of 0-40 is considered to be weakly erosive, between 40 and 60 a medium value, from 60 upwards toothpastes are very strongly erosive. We therefore advise against toothpastes with an RDA value above 60. The frequency of once a week for a medium abrasive toothpaste and once every two weeks for a highly abrasive toothpaste should not be exceeded.

Individually, the use of bleaching toothpaste is not recommended for patients with very thin enamel, as these are already more sensitive and less well protected than with a thicker enamel layer. Consultation with the dentist in charge is advisable to use the optimal product for the individual situation. A relatively new possibility to whiten the teeth is the bleaching lamp.

The lamps emit a bluish cool light. A whitening agent is first applied to the teeth to be bleached. The light from the lamp then activates the gel, which should give a more efficient result.

However, the gel consists of hydrogen peroxide, which has not been proven to be activated by light (regardless of wavelength). Furthermore, these lamps produce a lot of heat which can damage the teeth. At a temperature of 42 degrees Celsius at the latest, the blood and nerve vessels inside the pulp marrow die and the tooth dies.

Bleaching lamps are therefore not recommended. Bleaching at home or home bleaching is a popular option for many patients to whiten their teeth themselves about once or twice a year. Beforehand, a special plastic splint has been made in the dentist’s office by taking an impression, into which the bleaching preparation is inserted without the rest of the oral cavity coming into contact with the agent.

The preparation most commonly used is not hydrogen peroxide, but carbamide peroxide, which is much milder and has fewer risks. Hydrogen peroxide is about three times as strong as carbamide peroxide, which is why the time the splint is worn with the preparation is longer with carbamide peroxide. Teeth that have already been bleached should be left for about a year before the next application in order not to strain and damage the teeth.

Too frequent applications of home bleaching can make the teeth much more sensitive, so that cold stimuli in particular are more likely to cause pain. Bleaching at home can lighten the teeth by a maximum of two tooth shades. Larger jumps are not possible with the carbamide preparations.