Teeth whitening 16 carbamide peroxide
A 16% carbamide peroxide gel is a tooth-whitening material that releases hydrogen peroxide gradually in contact with saliva.
The short answer
Carbamide peroxide breaks down into hydrogen peroxide and urea. The peroxide moves through enamel and dentine and oxidizes some stain molecules, while urea changes the local chemical environment.
Why must whitening products and trays be professionally checked?
Use only a product and tray supplied or checked by a dental professional, and follow its wear instructions. Clean the tray, avoid gel on the gums, and pause if sensitivity or gum irritation develops.
What should you check before using whitening gel?
Have a dental examination first if you have cavities, cracked teeth, gum disease, exposed roots, or untreated sensitivity. Whitening does not change the colour of crowns, fillings, or veneers.
When should a dentist assess your teeth before whitening?
Is 16% appropriate for my teeth and tray? What is causing the discoloration, and how will existing restorations look after natural teeth are lightened?
Frequently asked questions
Can I whiten a tooth with a crown?
The crown itself generally does not lighten, so the colour match should be planned before whitening.
When should I arrange an examination?
Arrange an examination when symptoms persist, worsen, or interfere with eating, sleeping, cleaning, or normal function.
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.