Whitening strips use a low-concentration peroxide gel and are the cheapest way to lighten natural tooth color over a couple of weeks. Custom trays from a dentist hold carbamide or hydrogen peroxide gel evenly against teeth for more control. In-office whitening uses stronger gel for faster results. All can cause temporary sensitivity, and none change crowns, veneers or fillings. Results vary.
Whitening lightens the natural color of teeth with peroxide. The options differ in strength, fit, supervision and price.
Side by side
| Strips | Dentist trays | In-office | |
|---|---|---|---|
| Active ingredient | Low-concentration hydrogen peroxide | Carbamide or hydrogen peroxide gel | Higher-concentration hydrogen peroxide |
| Fit | One size | Custom molded | Applied by dentist |
| Time to results | About 1 to 3 weeks | About 1 to 2 weeks | One or two visits |
| Supervision | None | Dentist | Dentist |
| Cost | Lowest | Moderate | Highest |
| Sensitivity risk | Low to moderate | Moderate, adjustable | Higher |
Before you whiten
- Get a dental check first. Whitening over untreated decay or gum disease can cause pain.
- Know that crowns, veneers and fillings will not change color.
- Some stains, such as from certain medications or trauma, respond poorly.
Managing sensitivity
Use a sensitivity toothpaste for two weeks before and during whitening, take breaks between sessions, and do not exceed the product’s directions.
What to look for
Products with the ADA Seal have had their claims reviewed. Avoid products that promise guaranteed shades or use unlabeled ingredients.
Related: How to Clean Retainers and Clear Aligners Safely.
This is general information. Talk to your dentist about which option suits you. Browse whitening and appliances.
Common questions
Do whitening strips damage enamel?
Used as directed, approved products are considered safe for enamel. Overuse increases sensitivity and gum irritation.
What is the difference between carbamide and hydrogen peroxide?
Carbamide peroxide breaks down into hydrogen peroxide. A 10 percent carbamide gel is roughly 3.5 percent hydrogen peroxide.
Will whitening work on crowns and fillings?
No. Whitening only lightens natural tooth structure, so restorations may no longer match.
How long does whitening last?
Months to a few years, depending on diet, smoking and touch-ups.