Whitening
Tooth whitening uses peroxide to lighten stain in natural teeth, but a dental examination comes first when decay, gum disease, or sensitivity is present.
The short answer
Tooth whitening uses peroxide to lighten stain in natural teeth, but a dental examination comes first when decay, gum disease, or sensitivity is present. Existing restorations do not whiten like enamel.
How do peroxide gels break down tooth stains?
Hydrogen peroxide or carbamide peroxide breaks down coloured molecules within enamel and dentine. Surface deposits may also improve with professional cleaning, while intrinsic changes such as fluorosis, trauma, or tetracycline staining may respond differently.
What should you arrange before choosing a whitening method?
Arrange an examination and cleaning before selecting in-clinic whitening, a dentist-made tray, or another supervised method. Follow the prescribed gel amount and contact time, and pause if sensitivity or gum burning develops.
Which symptoms mean you should seek care before whitening?
Seek care for toothache, a single dark tooth, bleeding gums, exposed roots, or sensitivity that continues after whitening. These findings can signal pulp disease, decay, cracks, recession, or another problem needing diagnosis.
How can whitening affect fillings, crowns, enamel and gums?
Ask which stain is present, whether whitening will match your fillings or crowns, and which method fits your enamel and gum condition. Ask how sensitivity will be reduced and when the shade should be reviewed.
Frequently asked questions
Does whitening remove dental plaque?
No. Cleaning removes plaque and calculus; whitening changes the colour of natural tooth structure.
Why is one tooth darker than the others?
A dark single tooth can follow trauma, pulp damage, decay, or a restoration and should be examined before whitening.
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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.