Cosmetic whitening
Cosmetic tooth whitening uses peroxide to lighten stain molecules in natural teeth after the dentist checks enamel, gums, and restorations.
The short answer
Cosmetic tooth whitening uses peroxide to lighten stain molecules in natural teeth after the dentist checks enamel, gums, and restorations. It changes natural tooth color, but not the color of fillings, crowns, veneers, or bonding.
How does peroxide lighten stained teeth?
Peroxide penetrates enamel and dentin and breaks down colored organic molecules. Yellowing from age or dietary stains may respond differently from internal discoloration caused by trauma, medication, fluorosis, or a non-vital tooth.
What should be checked before choosing tooth whitening?
Have decay, gum inflammation, cracks, and existing restorations assessed before choosing in-office or dentist-prescribed home whitening. Follow the specified gel amount and exposure time, keep trays off the gums, and pause if sensitivity becomes significant.
When should tooth problems be treated before whitening?
Seek dental care before whitening for toothache, untreated cavities, gum disease, or a single dark tooth. Report persistent sensitivity, gum burning, or uneven color so the cause can be examined rather than treated with more gel.
What type of discolouration does whitening address?
Ask whether your discoloration is external or internal, whether restorations need replacement for color matching, and which delivery method fits your teeth. Ask how sensitivity will be managed and how the final shade will be assessed.
Frequently asked questions
Can whitening fix a single dark tooth?
A dark tooth may have internal pulp or dentin changes and needs examination before cosmetic whitening is selected.
Why do teeth feel sensitive after whitening?
Peroxide can temporarily irritate dentin pathways and the pulp, especially when exposure is excessive or teeth are already sensitive.
Who wrote this page
This library is published by Dental Nation, a licensed dental group practising in the United Arab Emirates. Pages are written and overseen by the same clinical team that treats patients in our clinics, and are held to a fixed editorial standard for safety and accuracy.
This page is patient education, not medical advice, and cannot replace an examination. Anything urgent — facial swelling, trauma, uncontrolled bleeding or severe pain — needs a dentist or emergency care now.