Teeth whitening is ideal for patients who have healthy, unrestored teeth (no fillings) and healthy gums who would like a brighter smile. Patients with yellow tones to their teeth respond best. But this cosmetic procedure is not recommended for everyone.
There are three general approaches:
Whitening toothpastes (dentifrices)
At-home bleaching (Dentist supervised tray-based whitening system)
In-office bleaching, also called chairside bleaching or power bleaching
All toothpastes help remove surface stains through the action of mild abrasives. Some whitening toothpastes contain gentle polishing or chemical agents that provide additional stain removal effectiveness. Whitening toothpastes can help remove surface stains only and do not contain bleach; professional whitening products contain hydrogen peroxide (a bleaching substance) that helps remove stains on the tooth surface as well as stains deep in the tooth. None of the home use whitening toothpastes can come even close to producing the bleaching effect you get from your dentist's office. Whitening toothpastes can lighten your tooth's color by about one shade. In contrast, light-activated whitening conducted in your dentist's office can make your teeth three to eight shades lighter.
At-Home vs At-the-Dentist Dental Bleaching: Main Differences
Strength of bleaching agent. For starters, dentist-supervised at-home products usually contain a lower strength-bleaching agent (from 10% carbamide peroxide-which is equivalent to about 3 percent hydrogen peroxide – up to 22% carbamide peroxide). In-office, professionally applied tooth whitening products contain hydrogen peroxide in concentrations ranging from 15 to 43 percent.
Mouthpiece trays. With dentist-supervised at-home bleaching products, your dentist will take an impression of your teeth and make a mouthpiece tray that is customized to exactly fit your teeth. This customization allows for maximum contact between the whitening gel, which is applied to the mouthpiece tray, and the teeth. A custom-made tray also minimizing the gel's contact with gum tissue. With in-office procedures, the bleaching agent is applied directly to the teeth.Additional protective measures. In the office setting, your dentist will apply either a gel to the gum tissue or use a rubber shield (which slides over the teeth) prior to treatment to protect your gums and oral cavity from the effects of the bleaching.
Speed of the bleaching process. Dentist-supervised at-home bleaching typically needs to be applied every day for 1 or 2 hours or every overnight for up to 4 weeks. In-office bleaching provides the quickest and most effective way to whiten teeth. 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, and/or a laser. The light and/or heat accelerate the whitening process. Results are seen in only 1, 30- to 60-minute treatment. To achieve dramatic results, however, several appointments are usually needed. With laser-enhanced bleaching, however, dramatic results can be seen after the first treatment.
Whitening is not permanent. People who expose their teeth to a lot of foods and beverages that cause staining may see the whiteness start to fade in as little as 1 month. Those who avoid foods and beverages that stain may be able to wait one year or longer before another whitening treatment or touch-up is needed.
Tips for maintaining your newly whitened teeth include:
Avoiding the consumption of or exposure to products that stain your teeth (see first question in this document on what causes teeth to become stained). If you do choose to consume beverages that stain, consider using a straw so that the liquid bypasses your front teeth.
Brush or rinse immediately after consuming stain-causing beverages or foods.
Follow good oral hygiene practices. Brush your teeth at least twice daily and floss at least once daily to remove plaque. Use a whitening toothpaste (once or twice a week only) to remove surface stains and prevent yellowing. Use a regular toothpaste the rest of the time.
Consider touch-up treatments. Depending on the whitening method used, you may need a tough-up every 6 months or after a year or two. If you smoke or drink lots of stain-causing beverages, you may need a touch up more often.
Risks Associated With Teeth Whitening
The two side effects that occur most often are a temporary increase in tooth sensitivity and mild irritation of the soft tissues of the mouth, particularly the gums. Tooth sensitivity often occurs during early stages of the bleaching treatment. Tissue irritation most commonly results from an ill-fitting mouthpiece tray rather than the tooth-bleaching agent. Both of these conditions usually are temporary and disappear within 1 to 3 days of stopping or completing treatment.
If you do experience sensitivity, you can reduce or eliminate it by:
Wearing the tray for a shorter period of time (for example, two 30-minute sessions versus two 60-minute sessions)
Stop whitening your teeth for two to three days to allow your teeth to adjust to the whitening process
Ask your dentist for a high fluoride-containing product, which can help remineralize your teeth. Apply the fluoride product to the tray and wear for 4 minutes prior to and following the whitening agent.
Brush your teeth with a toothpaste made for sensitive teeth. These toothpastes contain potassium nitrate, which helps soothe your teeth's nerve endings.
Teeth whitening is not recommended or will be less successful in the following circumstances:
Age and pregnancy issues. Bleaching is not recommended in children under the age of 16. This is because the pulp chamber, or nerve of the tooth, is enlarged until this age. Teeth whitening under this condition could irritate the pulp or cause it to become sensitive. Teeth whitening is also not recommended in pregnant or lactating women.
Sensitive teeth and allergies to products. Individuals with sensitive teeth and gums, receding gums and/or defective restorations should consult with their dentist prior to using a tooth whitening system. Anyone allergic to peroxide (the whitening agent) should not use a bleaching product.
Gum disease, worn enamel, cavities, and exposed roots. Individuals with gum disease or teeth with worn enamel are generally discouraged from undergoing a tooth whitening procedure. Cavities need to be treated before undergoing any whitening procedure. This is because the whitening solutions penetrate into any existing decay and the inner areas of the tooth, which can cause sensitivity. Also, whitening procedures will not work on exposed tooth roots because roots do not have an enamel layer.
Fillings, crowns and other restorations. Tooth-colored fillings and resin composite materials used in dental restorations (crowns, veneers, bonding, bridges) do not whiten. Therefore, using a whitening agent on teeth that do and do not contain restorations will results in uneven whitening-in this case, making the teeth without restorations appear lighter than those with restorations. Any whitening procedure should be done prior to the placement of composite fillings, bonding, veneers, crowns, dentures, or porcelain restorations in order to best match the degree of whitening to your new tooth color. A minimum of 2 weeks following a whitening procedure should be allowed before crowns, bondings, or veneers are completed. This will allow enough time for the enamel to remineralize and optimize the bonding strength. Tooth-colored fillings will need to be replaced after the bleaching process is complete. Individuals with numerous restorations that would result in uneven whitening may be better off considering bonding, veneers or crowns rather than a tooth whitening system. Ask your dentist what strategy may be best for you.
Unrealistic expectations. Individuals who expect their teeth to be a new "blinding white" may be disappointed with their results. Smokers need to be aware that their results will be limited unless they refrain from continued smoking, particularly during the bleaching process. A healthy guide as to a reasonable degree of whiteness to achieve with a whitening process that would give a natural appearance to a person's teeth is a slightly whiter color than the whites of your eyes.
Darkly stained teeth. Yellowish teeth respond well to bleaching, brownish-colored teeth respond less well, and grayish-hue or purple-stained teeth may not respond well to bleaching at all. Blue-gray staining caused by tetracycline is more difficult to lighten and may require up to 6 months of home treatments or several in-office appointments to successfully lighten. Teeth that have dark stains may be better candidates for another lightening option, such as veneers, bonding, or crowns. Your dentist can discuss the options best suited for your situation.
Will all types of bleaching procedures, the degree of whiteness will vary from individual to individual depending on the condition of the teeth, nature of the stain, the concentration of the bleach and the duration of time and bleaching system used.
Frequently Asked Questions
Do teeth whiteners damage tooth enamel?
Studies of whitening products using 10% carbamide peroxide showed little to no effect on the hardness or mineral content of a tooth's enamel surface.
Do teeth whiteners damage existing dental restorations?
Over 10 years of clinical use of whitening products containing 10% carbamide peroxide have not shown any damage to existing fillings. The issue is not "damage" to existing restorations; rather, keep in mind that existing restorations such as tooth-colored fillings, crowns, bonding, veneers, and bridges do not lighten. This means that any preexisting dental work may need to be replaced to match the new tooth shade achieved in the natural teeth, should a bleaching process proceed.
Do teeth whiteners damage a tooth's nerve?
There's no evidence to date that the tooth whitening process has a harmful effect on the health of a tooth's nerve. One study reported that at both a 4.5 and 7-year follow up, no individual who used a tooth whitening system needed a root canal procedure on any teeth that had been whitened.