Tooth-whitening products and services have been around for decades, but the era of reality television - particularly makeover shows - made teeth whitening less of a luxury and more of a priority to consumers. In image-conscious 2006, nobody is satisfied with yellow stains or brownish hues on their teeth, and people have many options for brightening up their smiles.

However, experts say, whether you whiten via a dentist or with an at-home product, the success of this confidence-building gesture is typically a matter of expectation.

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"I try to make sure the patient has realistic expectations," said Dr. Michael Kirk, D.D.S., who runs Oklahoma City's Grand Dental Studio.

Those expectations, he said, could vary from teeth just a couple shades whiter to five or six shades whiter.

While going to a doctor such as Kirk may intimidate some, Procter & Gamble's Crest-brand Whitestrips nearly single-handedly turned the process of teeth whitening into something that could be achieved via a grocery store purchase.

"They ... kind of spent a lot of marketing dollars all at once," Kirk said.

But how do you separate the marketing from the results? What options do consumers have to get that Hollywood-white smile? How long will it take to achieve results? What does it cost, and how much will it hurt?

Again, it depends on expectations.

All teeth whitening does is remove stains, according to an article written by Dr. Jerry Gordon, by using bleaching chemicals to dissolve stains on tooth enamel. Your chances of whitening success depend on the type of stains.

Dentists say one of the simplest ways to work toward whiter teeth is to alter some personal habits: Quit smoking. Cut back on coffee and red wine. Make frequent trips to the dentist for formal cleanings.

However, for those who need more than that, there are two options: Do-it-yourself whitening and at-the-dentist whitening.

Do It Yourself

According to Dr. Harold Katz on Therabreath.com, founder of the California Breath Clinics, there are three kinds of at-home whitening products: brush-on products, strips placed on teeth and bleaching trays.

Most any store with a significant pharmacy section will have the products. Whitestrips, the initial marketplace standard-bearer for the bight-smile movement, will run a shopper about $35 per package.

The primary advantages of at-home whitening products are cost and convenience. At-home treatments cost significantly less than work done in a dentist's chair. Plus, it can be done on any schedule.

However, hygienists with Grand Dental Studio noted that while at-home treatments can produce results, they might take several weeks to do so, often frustrating consumers enough to give up on over-the-counter efforts.

"Most people do (try) the take-home first," before going to a professional, Kirk said.

There is the possibility of some pain and sensitivity when doing any sort of teeth whitening. Most whitening kits are powered by carbamide peroxide, which can cause some sensitivity, usually lasting no more than 24 hours. Whitestrips' active ingredient, for example is hydrogen peroxide, which is derived by mixing carbamide peroxide and saliva.

Either way, it's hydrogen peroxide doing the work.

At The Dentist

At Kirk's Oklahoma City dental office, customers pay anywhere from $350 to $1,000 for whitening. His prescription for most customers is a one-hour power whitening session with laser light, followed up by two days of work at home. For most people, that produces desired results.

Kirk said there is less pain when pursuing whitening via a dentist because there is only one major session, as opposed to weeks of work, which can cause some general soreness.

Many people choose to supplement a dentist's visit with over-the-counter whitening products to maintain white teeth. However, the dentist acknowledges that going through the whitening process isn't necessarily a permanent solution.

"Even if you whiten, it's going to get old after a while," Kirk said.

He advises many patients to consider more permanent solutions such as veneers or a product called Lumineers, which are porcelain covers that "do not require removing painful tooth structure," according to a promotional Web site.

"I think there is more of a trend toward more permanent solutions," Kirk said.

Dentists say that two groups of consumers might be better served by alternative whitening techniques: Those with teeth that are discolored but not yellow and those whose teeth need restoration, such as fillings and crowns.

Experts say that yellowed teeth respond much better to whitening procedures than brown or gray teeth. Furthermore, while whitening is ideal for people with unrestored teeth and healthy gums, a dentist's visit is recommended before starting any whitening program.