Crest 3d strips before and after
Whitening strips can lighten some surface and internal stains, but results vary with stain type, tooth color, fit, and whether restorations are present.
The short answer
Whitening strips use a peroxide gel to lighten some natural tooth stains, but the visible change depends on the stain, exposure pattern, tooth color, and existing restorations.
How does peroxide gel contact the enamel surface?
Whitening strips are flexible carriers coated with a peroxide-based gel that contacts the outer enamel surface. The active compound diffuses into enamel and dentin and can break down some stain molecules, but it does not whiten fillings, crowns, veneers, or bonding.
How should whitening strips be placed and used safely?
Follow the product directions and keep the strip on the teeth it is designed to cover, avoiding the gums. Stop if marked sensitivity or gum irritation occurs, and have dark single-tooth discoloration or cavities assessed before whitening.
When is an examination needed before whitening?
Ask for an examination before whitening if you have decay, cracked enamel, gum recession, untreated sensitivity, or a restoration in the visible area. Seek care for pain, a persistent white or brown patch, or uneven color that does not match normal surface staining.
How will whitening affect existing visible restorations?
Ask whether the discoloration is external or internal, whether the teeth and gums are healthy enough for whitening, and how existing restorations will appear afterward. Ask which concentration and application pattern fit your teeth.
Frequently asked questions
Will strips whiten one dark tooth?
A single dark tooth may have internal discoloration or previous trauma and should be assessed before using a general strip product.
Why can strips make teeth sensitive?
Peroxide can temporarily move through enamel and dentin and irritate the pulp or exposed root surfaces.
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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.