Options for getting whiter teeth

Q. I’m 68 and my teeth are yellow. I’m thinking of getting them whitened. Is it worth it?

Whitening processes are effective. Based on clinical studies, 96 percent of patients with common stains experience some lightening effect.

But, be forewarned that whitening has to be repeated periodically if you want to maintain a sparkling smile. Whiteness can start to fade in a month.

The least expensive option is a bleaching system you buy over the counter and use at home yourself. A home-bleaching system that your dentist supervises is the next step up. Getting your teeth done in a dentist’s office usually is the most expensive procedure. Costs vary widely.

In addition to these options, you can get your teeth whitened with bonded resins and porcelain veneers. Bonding a composite resin onto the teeth can change its color. This procedure usually can be done in one office visit. Porcelain veneers can be bonded onto stained teeth to whiten them.Veneers require at least two office visits.

There are also “whitening” toothpastes. These toothpastes don’t change the shade of your teeth, but help prevent stains from sticking to your teeth. Whitening toothpastes can be used to help preserve the results of a whitening procedure.

The most common reasons for yellow teeth are:

• Aging. As we age, we accumulate surface stains. Also, the insides of our teeth yellow and can be seen through the outer enamel as it gradually becomes thinner over time.

• Tobacco that is smoked or chewed.

• Beverages such as coffee, tea, red wine and dark-colored soda.

• Foods such as blueberries, tomato sauce, curry and soy sauce.

You can also have stains within a tooth. These can be caused by too much fluoride or certain antibiotics during tooth development. These stains are harder to treat than surface stains.

How should you proceed? I recommend seeing your dentist first. Don’t go to the drugstore and start putting chemicals on your teeth without professional advice. Then choose the technique that is appropriate for you. Here are more details about your choices:

At home

There are several types of products available for use at home, which can either be dispensed by your dentist or purchased over-the-counter.

OTC products include clear, peroxide-based gels you apply with a small brush. And there are almost invisible strips coated with a peroxide-based whitening gel that you place on your teeth.

The most popular option is doing the whitening at home under your dentist’s supervision. You get trays molded to your teeth. These hold a peroxide whitening agent. The trays are usually made in one office visit. Then you wear the trays at home. Some products are used for about twice a day for two weeks, and others are intended for overnight use for one to two weeks.

Products used at home usually are not as strong as those used in a dentist’s office.

In the dentist’s office

In-office whitening can take between 30 and 90 minutes and can require up to three appointments. Or, whitening may involve two to six visits of about 45 minutes each.

With in-office bleaching, the whitening product is applied directly to the teeth. These products can be used in combination with heat, a special light, or a laser to accelerate the whitening.

Any cavities must be treated first, because the whitener can penetrate decay and cause sensitivity. Whitening will not work on exposed tooth roots, because roots do not have an enamel layer. Receding gums—an age-related problem—can cause roots to become exposed. Whitening also does not work on crowns or veneers.

Regular whitening may not improve the appearance of a tooth that has had root-canal treatment. A dentist can employ a special treatment to whiten the tooth from the inside.