The research by one dentist was generally overlooked for almost 2 decades. A - I t is hypothesized that the pigments in the tooth are oxidized. Anywhere from a few days to a few weeks. When dealing with extreme stains, there are cases that have taken months to complete. A-Carbamide peroxide and hydrogen peroxide.
Some people get some sensitivity in their teeth.
This can be handled with desensitizers or changing from the usual tray wearing regimen. Can I continue to use the whitening gel in the future. These can cause significant structural damage to the enamel when used for extended periods. Other types of OTC products have abrasives that will remove surface stains and make the teeth look whiter - the problem with these is that they also remove a small amount of enamel due to their abrasiveness. This is a whitening tray being loaded with the whitening gel.