Teeth whitening

What it is

Your tooth color comes from two layers. Enamel (the hard outer layer) is partly see-through. Under it is dentin (the yellower layer that makes up most of the tooth). As enamel thins with age and picks up stains, more of that yellow shows through.

• AEnamel
• BDentin
• CPulp
• DGum
• ERoot canals
• FBone

1. AEnamel
2. BDentin
3. CPulp
4. DGum
5. ERoot canals
6. FBone

Whitening gel contains a peroxide (a bleaching ingredient) that breaks down stains inside the tooth, not just on the surface. Dentists offer it in two ways:

• In the office. A stronger gel is used while your gums are covered and protected. It often takes one visit.
• At home with custom trays. Thin trays are made to fit your teeth. You wear them with a milder gel for a set time each day, often for a week or two.

Who it helps

Whitening tends to work well on yellow stains from age, coffee, tea, red wine, and tobacco. It often works less well on gray or brown stains, such as those from some antibiotics taken in childhood, and on white spots.

It won’t change the color of crowns, fillings, veneers, or bonding, so these may stand out once your teeth are lighter.

Whitening may not be a good idea if you have cavities, gum disease, or exposed roots, because the gel can make them sore. Many dentists also suggest waiting until after pregnancy and breastfeeding.

What happens

In-office whitening usually goes like this:

1. Exam and cleaning. Your dentist checks for cavities and gum problems, and a cleaning removes surface stains. You’ll note your starting shade together.
2. Protecting your gums. A plastic holder keeps your lips and cheeks back, and a protective coating is painted over your gums. Keeping your mouth open can get tiring, so ask for a break if you need one.
3. Applying the gel. The gel sits on your teeth for a set time, and then it’s removed and often applied again. Some people feel brief, sharp twinges.
4. Checking the shade. The gel is rinsed off, and your new shade is compared with where you started.

Take-home whitening starts with the same exam. Then your dentist makes trays from impressions (molds or digital scans) of your teeth. You’ll learn how much gel to use, and your dentist checks how it’s going.

Recovery and aftercare

There’s no healing time. The most common side effect is sensitivity: teeth may ache or twinge, and gums may feel irritated, for a day or two. It usually fades on its own, and toothpaste for sensitive teeth can help.

For the first day or two, your teeth pick up stains more easily. Many dentists suggest going easy on coffee, tea, red wine, and tobacco during that time. Results fade slowly, and touch-ups can help keep your shade.

Cost and insurance

The cost depends on the method, how many sessions you need, and whether trays are made. Touch-up gel adds some cost later.

Dental plans usually treat whitening as cosmetic and don’t cover it, though the exam and cleaning beforehand may be covered as usual. Financing can spread the cost; see insurance and financing.

Alternatives

• A professional cleaning. If most of the stain is on the surface, a cleaning may brighten your teeth enough.
• Store-bought strips or toothpaste. These cost less. Toothpaste mostly removes surface stains, and strips work more slowly than a dentist’s gel.
• Bonding or veneers. For stains that bleaching can’t lift, bonding or veneers cover the front of the tooth. Both change more than color, and veneers mean removing some enamel.
• Leaving your teeth as they are. Natural teeth aren’t bright white, and a yellow tint isn’t a sign of poor health.