With chemicals that react with dirt that darkens teeth. The process is simple and consists of applying a gel and letting it act for a few minutes. It is possible to whiten entirely with the dentist, arrange sessions in the office with others at home or do everything just at home.
To get better results, it’s worth making several lightweight applications over a long time (30 in a month, for example). People with particularly sensitive gums or enamel problems should talk to their dentist before attempting to bleach, as there may be contraindications. The procedure also has less effect on blemishes caused by the use of antibiotics.
1) The tooth is formed by several overlapping layers. The most superficial is the enamel, which is naturally porous. Over time, pieces of food enter through these micro-cracks and settle on the layer beneath the enamel, dentin. It is the accumulation of this material that darkens the tooth.
2) Before performing the procedure, a basic cleaning of the tooth structure is necessary . The dentist uses a tool called a curette to clean plaque and tartar. This process increases the effectiveness of bleaching and avoids pain and damage to some particularly sensitive area.
3) It is also necessary to protect the gums. If the application is in the office, the most common is to cover it with a protective liquid, which is then exposed to a beam of light that makes it more rigid, like a rubber. At home, as the whitening substance is applied to a mold, it does not touch the gums.
4) The dentist applies the bleaching gel to the teeth with a syringe. In all cases, the active ingredient is hydrogen peroxide (the popular hydrogen peroxide) or carbamide peroxide (most commonly used). Both cause an oxidation reaction and break down organic molecules, such as those derived from food.
5) The gel penetrates the cracks and reacts with the substances. The reaction causes the stain molecules to be broken down into smaller pieces, such as ammonia (NH3), carbon dioxide (CO2) and oxygen (O2). They detach themselves from the dentin and are expelled from the tooth. As the process is slow, several sessions are required.
6) In cases where it is desired to accelerate the result, a potent source of light can be used to stimulate the reaction of the peroxide with the spots. This produces more oxygen, the main “cleansing” agent. However, some studies question the actual efficacy of this technique.
7) In each session in the office, the patient stays for 20 to 30 minutes with the gel in his mouth. To clean the tooth, the dentist just squirts it with water, eliminating leftovers from chemical reactions. At home, it is six hours with the gel, which may be during sleep, and the product is removed with brushing.