Crest 12 levels whiter before and after
Whitening strips use peroxide to lighten some natural tooth stains, but results vary with the stain, fit, use, and restorations.
The short answer
Whitening strips are flexible plastic carriers coated with a peroxide-containing gel that contacts the front surfaces of natural teeth. Before-and-after results cannot be predicted from a product label alone, and restorations such as fillings, crowns, and veneers do not bleach like enamel.
What is the direct answer?
What does this question mean?
Peroxide breaks down stain molecules within enamel and dentin. Uneven contact, calculus, intrinsic staining, cracks, or restorations can make the result look patchy. A dentist checks cavities, gum recession, enamel wear, sensitivity, and restoration shade before recommending a whitening plan.
What can you do next?
Follow the product directions exactly, keep gel off the gums, and stop if pain or marked sensitivity develops. Do not extend wear time or combine multiple whitening products without professional guidance. Use a soft brush and fluoride toothpaste, and arrange a dental cleaning if deposits are contributing to the color.
Frequently asked questions
Why did my strips whiten unevenly?
Coverage can differ around tooth shape, spacing, calculus, enamel defects, or restorations, so the gel may not contact every area in the same way.
Will whitening last permanently?
The shade can change again as teeth pick up new stain; maintenance depends on diet, tobacco exposure, oral hygiene, and the original cause of discoloration.