How does bleaching with hydrogen peroxide work?

Whether it is for bleaching clothes, hair or even teeth, in each of these cases hydrogen peroxide is the bleaching agent of choice. Hydrogen peroxide consists of a compound of hydrogen and oxygen. In the dental field, products with a concentration not exceeding 0.1% are freely available.

These belong to cosmetic products. All higher concentrated preparations are subject to dental use. The dentist uses concentrations between 10% and 40% where the gums must be protected in order not to come into contact with the hydrogen peroxide.

Swallowing the preparations can also lead to vomiting and burns of the oesophagus. Therefore these concentrations are far too dangerous for the user at home and should be carried out under medical instruction and supervision. The dentist distinguishes between in-office bleaching, where bleaching is carried out in the practice under supervision using a specially made bleaching tray, and home bleaching, where the patient carries out the application at home.

Bleaching pencils, toothpaste and similar products are available in the trade, which are part of the cosmetic products. However, the low concentration of these products does not mean that they should be used excessively often, as they can also damage the teeth. The instructions for use must therefore be strictly adhered to, and the dentist should be consulted if anything is unclear.

It is important to have bleaching carried out by a dentist and to have the health of the teeth to be bleached checked first. The dentist should check that the teeth to be bleached have no caries and that the surrounding gums are not irritated, inflamed or affected by periodontosis. In addition, the dentist should be able to assess what the cause of the discolouration of the teeth is (normal age-related discolouration, metabolic discolouration, discolouration caused by food).

Only healthy teeth should be bleached. Before teeth bleaching, the teeth to be bleached are first cleaned. For this purpose, the tooth surfaces and the adjacent gum areas are cleaned with a strong water jet. For this purpose, the gums are slightly lifted with an instrument at the regions adjacent to the tooth and the gum pockets are rinsed under. Bleaching can only begin after cleaning and after a health check.

Is bleaching unhealthy for the teeth?

In general, the use of hydrogen peroxide is a cosmetic treatment that carries risks. Regardless of the product and its concentration, hydrogen peroxide causes the removal of liquid from the teeth. This dehydration implies that the teeth are more sensitive to thermal stimuli.

Cold and heat stimuli that did not pose any problem before treatment can cause pain after application. In the case of insensitive teeth, a rare application about once a year can cause no subsequent complaints, whereas the treatment of pain-sensitive teeth is rather disadvised. Whether a tooth is resistant to external stimuli depends on the thickness of the uppermost layer of the tooth’s hard tissue, the enamel.

If the enamel is particularly thick, bleaching usually does not cause any problems at all. If the enamel layer is thin, a single application can already cause severe pain. Therefore, it cannot be generally said that bleaching is healthy or unhealthy. Nevertheless, the application should be weighed with caution. In order to be sure that the application is suitable, an informative conversation with the dentist should be held beforehand, so that the dentist can select the optimal preparation and the appropriate application for the patient, so that a lasting, gentle whitening is achieved.