Over-the-counter products are best for those who don't want to spend megabucks and don't need the instant gratification of a professional treatment. Follow these steps to get the best results.
In-office bleaching could set you back $300 to $600, but the 16 to 25 percent peroxide can lighten your teeth six shades or more. Here's how to get the most out of spending the extra money:
Can bleaching harm my teeth?
There are no studies that have proven that hydrogen or carbomide peroxide can cause permanent damage, because they maintain the enamel coating, according to Dr. Rosen. However, skip a product if it has an acid on the ingredients list (although most brands on the market don't include acids, it's still smart to check the label). "It etches away the superficial layer, leaving a chalky residue," explains Dr. Rosen.
Why do my teeth feel sensitive after whitening treatments?
Sensitivity can be caused by overuse of at-home products containing acids (like citric acid), which strip outer layers of enamel. "You can feel a slight zinging to a more intense pain, especially with hot or cold temperatures," explains Dr. Liechtung. This is normal and should diminish in 24 to 48 hours post-treatment, but if it lasts longer, consult a dentist.
How white is too white?
On the shade guide used by dentists, B1 is the whitest hue. However, due to overbleaching, new shades have been added that are considered whiter than what's naturally possible (OMI, OMII and OMIII). "Teeth in the OM category can stop reflecting light and appear gray," says Dr. Rosen. To reach this super-white level you'd have to have repetitive professional whitening, which would likely not be recommended by a dentist.
Can I change the color of my caps and veneers?
No, only your natural teeth can be lightened by bleaching agents. Because caps and veneers are artificial, peroxide can't change their hue, so dentists recommend that you seek a professional's advice instead of using over-the-counter kits. Dentists can usually bring caps and veneers back to their original shade through cleaning and polishing, helping your teeth to maintain a uniform look.
FITNESS staffers put over-the-counter tooth brighteners to the test.
Colgate Luminous Enamel Strengthening Toothpaste in Mint Twist, $2.99, drugstores
The claim: Fluoride gently lifts away surface stains, while minerals help rebuild weak enamel so teeth appear whiter.
Our tester says: "The texture wasn't abrasive like other whitening toothpastes I've tried and the mint flavor made my mouth feel really clean." —Sara, 24
The pro says: "By removing tartar on a daily basis and strengthening the enamel in between professional cleanings, it will make your smile brighter," says Dr. Liechtung.
GoSmile Zen Toothpaste for Sensitive Teeth, $18, sephora.com
The claim: Potassium nitrate helps block exposed areas in the enamel, while silica polishes away stains and fluoride prevents decay and strengthens the enamel.
Our tester says: "The paste felt slightly chalky but my teeth didn't have the sensitivity they usually do while brushing." —Tara, 28
The pro says: "Minerals combined with your saliva help to close off exposed nerve fibers and lessen sensitivity from overwhitening," says Dr. Rosen.
Crest Whitestrips Daily Multicare, $39.99, drugstores
The claim: Daily use of these five-minutes-a-day formfitting gel strips prevents stain buildup, whitening teeth several shades after one kit (42 pouches).
Our tester says: "I noticed a slight difference after one week, but once I finished the box, I got tons of compliments on my super-white smile." —Nicole, 27
The pro says: "Even low amounts of peroxide can have a big effect — it's really about using the active ingredient on a consistent basis," says Dr. Rosen.
Listerine Whitening Pre-Brush Rinse, $5.49, drugstores
The claim: Germ-fighting ingredients prevent bad breath, while whitening agents brighten your smile after 12 weeks. Our tester says: "I didn't like the taste it left behind, but my teeth are whiter and it's super-easy to use." —Kathy, 45
The pro says: "A whitening rinse is a great tool to prevent already whitened teeth from rebounding back to their original shade," says Dr. Liechtung.
Sally Hansen Smile Brightening Lip Treatment in Radiant, $6.95, drugstores
The claim: The blue-based hues diffuse yellow tones and make not-so-bright smiles seem super-white.
Our tester says: "I never think my teeth look really white, so I loved applying a gloss to instantly make my smile seem brighter." —Jenna, 31
The pro says: "The color white that your eye can see naturally has blue undertones," explains Dr. Rosen.
Tip: Watch what you sip. Coffee, tea, dark soda and red wine (and, of course, cigarettes) can penetrate teeth's enamel and cause yellowing. "Skip them entirely for 24 hours after a professional treatment, when teeth are more apt to absorb dark hues, or use a straw to lessen the contact," advises Dr. Rosen.
Originally published in FITNESS magazine, April 2007.