Whitening strips contain peroxide that breaks down stains on tooth enamel.
How they work
Strips are coated with a peroxide gel, usually hydrogen peroxide or carbamide peroxide (3% to 10%). It penetrates the enamel and breaks down stain molecules.
Results
Teeth can be about 1 to 3 shades lighter after 7 to 14 days.
Side effects
Tooth sensitivity and gum irritation.
Tips
- Follow the label on time.
- Don’t overuse.
- Stop if sensitivity worsens.
Not for
Crowns, fillings or veneers: they don’t whiten.
Active ingredient
Most whitening strips contain hydrogen peroxide (about 6% to 14%) or carbamide peroxide, which breaks down into hydrogen peroxide. The peroxide releases oxygen that penetrates enamel and breaks down stain molecules inside the tooth. Whitening changes the color of stains, rather than removing the surface.
Typical use
Strips are applied for 30 minutes once or twice daily for 7 to 14 days, according to the product instructions. Results are typically visible in a few days.
Results
Clinical studies show strips can lighten teeth by several shades, with effects lasting 3 to 12 months depending on diet and habits. Coffee, tea, red wine and smoking cause restaining.
What does not whiten
Whitening does not change the color of crowns, veneers, fillings or dentures. It works best on yellow stains and less well on gray stains from medications such as tetracycline.
Side effects
- Tooth sensitivity, in up to 50% or more of users, usually temporary.
- Gum irritation from contact with peroxide.
- Uneven results where the strips don’t cover.
Overuse can erode enamel.
ADA Seal
The American Dental Association gives its Seal of Acceptance to some whitening products after testing safety and effectiveness. Look for it on the package.
Tips
- Brush gently and floss before applying.
- Avoid staining foods for a few hours afterward.
- Use a desensitizing toothpaste with potassium nitrate if teeth are sensitive.
- Do not exceed the recommended time.
Who should not use
Children under 12 or 14 (check the label), pregnant or nursing women unless approved by a dentist, and people with gum disease, cavities or exposed roots until treated.
Dentist options
In-office whitening uses higher concentrations, and results are quicker but cost more.
Ingredients and how to use
Whitening strips are thin plastic strips coated with a peroxide gel, usually 6 to 14 percent hydrogen peroxide or a carbamide peroxide equivalent, which breaks down stain molecules in enamel. Typical use is 30 minutes once or twice a day for 7 to 14 days. Results vary, with many users seeing a lightening of one to several shades, and effects can last several months, longer if you avoid coffee, tea, red wine and tobacco. Strips do not whiten crowns, veneers or fillings and work less on gray stains caused by medicines such as tetracycline.
Side effects and dentist options
Up to about half of users report temporary tooth sensitivity or gum irritation. Do not exceed the recommended time, and use desensitizing toothpaste if needed. Look for the American Dental Association Seal of Acceptance. Those with cavities, gum disease, exposed roots or pregnancy should ask a dentist first. In office whitening uses peroxide at 25 to 40 percent and usually costs several hundred dollars, while custom trays from a dentist provide a middle option. Avoid overuse, which can damage enamel.
Based on data from the American Dental Association
