16 Carbamide peroxide teeth whitening
A 16% carbamide peroxide gel releases hydrogen peroxide to lighten some tooth stains when used in a correctly fitted tray.
The short answer
A 16% carbamide peroxide product is a tooth-bleaching gel, not a polishing paste. Carbamide peroxide breaks down into hydrogen peroxide and urea, allowing peroxide to diffuse through enamel and dentine and oxidise some stain molecules.
What should be checked before using whitening gel?
A dentist checks for decay, cracks, leaking fillings, gum recession, and existing crowns or veneers before whitening. The tray is fitted so gel contacts tooth surfaces without pooling against the gingiva, and instructions specify application time and frequency.
How should you apply carbamide peroxide whitening gel?
Follow the supplied tray instructions, use only the intended amount, and wipe away gel that reaches the gums. Stop and arrange advice if marked sensitivity, gum soreness, or a burning sensation develops.
When should whitening wait for a dental examination?
Have a dental examination before use if you have untreated decay, painful sensitivity, gum disease, pregnancy-related questions, or restorations whose colour cannot change with peroxide.
What should you ask about whitening safety and sensitivity?
Ask whether the concentration suits your teeth, how long each application should remain, which restorations will not whiten, and how sensitivity or uneven shade will be managed.
Frequently asked questions
Will it whiten a crown?
No. Ceramic and most restorative materials keep their existing shade, so whitening can reveal a colour difference.
Why can teeth feel sensitive?
Peroxide can move through tooth structure and temporarily irritate the pulp or expose sensitivity at recession or defects.
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.