Results are subjective,

varying considerably from person to person. Many are immediately delighted with their outcome, while others may be disappointed. Before you embark on any whitening treatment, ask your dentist for a realistic idea of the results you are likely to achieve and how long it should take to achieve them.

In the dental office, before-and-after tooth color is typically measured with shade guides. These are hand-held displays of wide ranges of tooth colors. (Dentists also use them in choosing crown and other restoration shades.)

The standard-setter among them has long been the Vitapan Classic Shade Guide. This shade guide standard incorporates 16 shades, systematically arranged from light to dark into four color groups, and provides a universal tooth-color terminology.

While whitening can occasionally lighten tooth color by nine or more shades, most of those who bleach their teeth are likely to see a change of two to seven shades.

Risks

Teeth whitening treatments are considered to be safe when procedures are followed as directed.

However, there are certain risks associated with bleaching that you should be aware o

• Sensitivity: Bleaching can cause a temporary increase in sensitivity to temperature, pressure and touch. This is likeliest to occur during in-of ce whitening, where higher-concentration bleach is used. Some individuals experience spontaneous shooting pains (“zingers”) down the middle of their front teeth. Individuals at greatest risk for whitening sensitivity are those with gum recession, signi cant cracks in their teeth or leakage resulting from faulty restorations. It has also been reported that redheads, including those with no other risk factors, are at particular risk for tooth sensitivity and zingers. Whitening sensitivity lasts no longer than a day or two, but in some cases may persist up to a month. Some dentists recommend a toothpaste containing potassium nitrate for sensitive teeth.
• Gum irritation: Over half of those who use peroxide whiteners experience some degree of gum irritation resulting from the bleach concentration or from contact with the trays. Such irritation typically lasts up to several days, dissipating after bleaching has stopped or the peroxide concentration lowered.

Maintaining Your Results

To extend the longevity of newly whitened teeth, dentists are likely to recommend:

• At-home follow-up or maintenance whitening – implemented immediately or performed as in frequently as once a year.
• Avoiding dark-colored foods and beverages for at least a week after whitening.
• Whenever possible, sipping dark-colored beverages with a straw.
• Practicing excellent oral hygiene – brushing and flossing after meals and at bedtime.

Caveats

In addition to the aforementioned risk factors, a number of caveats should be considered before undergoing teeth whitening:

• No amount of bleaching will yield “unnaturally” white teeth.
• Whitening results are not fully seen until approximately two weeks after bleaching. This is an important consideration if you are about to have ceramic restorations and want to be sure the color matches that of your newly bleached teeth.
• If cosmetic bonding, porcelain veneers or other restorations are part of your treatment plan, they should not be placed until a minimum of two weeks following bleaching to ensure proper adhesive bonding, function and shade matching.
• To avoid the technicolor effect, tooth-colored restorations will likely need replacement after bleaching.
• Recessed gums often reveal their yellowish root surfaces at the gum line. That yellow color has proven dif cult to bleach.
• Pregnant or nursing women are advised to avoid teeth whitening. The potential impact of swallowed bleach on the fetus or baby is not yet known.