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 do the whitening entirely with the dentist, combine sessions in the office with others at home, or do everything just at home.
For best results, it’s worth doing several light applications over a long period of time (30 in a month, for example). People with especially sensitive gums or enamel problems should speak to their dentist before trying whitening, as there may be contraindications. The procedure also has less effect on stains caused by antibiotic use.
Check out the step-by-step below.
– (Filipe Campoi/)
1) The tooth is made up of several superimposed layers. The most superficial is enamel, which is naturally porous. Over time, little pieces of food enter through these micro-fissures and are deposited in the layer below the enamel, the dentin. It is the accumulation of this material that darkens the tooth.
two) Before carrying out the procedure, it is necessary to make a basic cleaning in tooth structure. The dentist uses a tool called a curette to clean away plaque and tartar. This process increases the effectiveness of whitening and prevents pain and damage to any particularly sensitive areas.
3) It is also necessary to protect the gum. If the application is in the office, the most common is cover it with a protective liquid, which is then exposed to a beam of light that makes it more rigid, like rubber. At home, as the whitening substance is applied in a mold, it does not touch the gums.
4) The dentist apply the whitening gel on the teeth with a syringe. In all cases, the active ingredient is hydrogen peroxide (the popular hydrogen peroxide) or carbamide peroxide (the most used). Both cause an oxidation reaction and break down organic molecules, such as those derived from food.
5) O gel penetrates the cracks and reacts with substances. The reaction causes the stain molecules to be decomposed into smaller pieces, such as ammonia (NH3), carbon dioxide (CO2) and oxygen (O2). They detach from the dentin and are expelled from the tooth. As the process is slow, several sessions are required.
6) In cases where you want to speed up the result, you can use a powerful source of light to stimulate the peroxide reaction with the spots. This produces more oxygen, the main “cleaner” agent. However, some studies question the real effectiveness of this technique.
7) In each session in the office, the patient spends 20 to 30 minutes with the gel in the mouth. For clean tooth, the dentist just squirts it with water, eliminating leftovers from chemical reactions. At home, it takes six hours with the gel, which can be during sleep, and the product is removed by brushing.
CONSULTANCY Sizenando de Toledo Porto Neto, professor at the Department of Restorative Dentistry at Unesp in Araraquara
SOURCES American Dental Association