One of the easiest ways to transform your appearance is by brightening your smile. Stained, yellowed teeth make people appear older and less healthy, and whitening is a simple process that can result in a remarkable difference.

Over-the-counter tooth whitening kits are inexpensive and easy to use. “I’ve got some patients who just swear by them, and they think that whitening strips work great,” says Dr. Charles Fuszner, a St. Louis dentist who specializes in cosmetic dental procedures. “Other people have used them and actually spent a lot of money and have seen no results.”

Fuszner says the secret to whitening is less in the chemical and more in the ability to reach every nook and cranny with the whitening agent. That’s where professional whitening can trump strips since whitening strips can be difficult to attach tightly to every contour of the teeth.

To achieve the objective of allowing the bleaching agent to reach all portions of the enamel, custom whitening systems include a tray made to fit the individual by using a mold of the teeth made in the dentist’s office. The whitening chemical is then put into the tray, and the individual generally wears it for one to two hours per day for a two-week period.

“You need to hold the product right up against the tooth for a certain period of time,” Fuszner says. The amount of time needed daily varies somewhat depending on the type of whitening agent used. “There are ways to get around almost anything that is objectionable about the normal, standard process. If somebody wants it done faster or has sensitivity issues, there are ways you can work around that.” However, diverting too much from the typical two-week process can result in less predictable results.

“The next level of whitening is done in the dental chair, in the office,” says Dr. Douglas Watanabe, a dentist with Ballas Dental Care. This ‘chair-side’ process involves very strong chemical agents that can whiten teeth within about an hour but require careful shielding of the gums and soft tissues throughout the procedure.

“The only detrimental aspect of this occurs if you have gum recession and root exposure or sensitive teeth that cause pain and sensitivity to cold,” Watanabe says. “There are treatments that help with that.” He adds that people with sensitive teeth need to be cautious about the whitening process regardless of what type of procedure they choose.

Not everyone is a good candidate for tooth whitening, and realistic expectations are important to a satisfactory outcome. For instance, grayish discoloration caused by the use of tetracycline, often as a child, is difficult to change. It may be lightened a bit but is unlikely to disappear completely. Crowns and fillings will not change color, although some patients with very discolored teeth that are not prone to whitening may choose to explore the option of porcelain veneers, which can give the smile a more consistent color and tooth shape.

Fuszner notes that whitening procedures have been around for years yet have retained their popularity, especially among older people who seek a younger, fresher appearance. Watanabe agrees, saying, “It’s a simple, readily available dental procedure that’s relatively inexpensive.” With so little to lose, it’s worth a conversation with your dentist.