Teeth Whitening

Definition

Teeth whitening is the process of using bleach or other materials to make teeth look whiter. The materials remove stains or other discoloration from the tooth surface.

Purpose

Teeth whitening is a cosmetic treatment done to improve the appearance of teeth. Teeth are whitened to remove the effects of coffee, cigarettes, and other substances that permanently stain or discolor teeth. Medications such as antibiotics like tetracycline may discolor teeth. Fluorosis, a condition caused by absorbing too much fluoride, could affect tooth color. Furthermore, aging also causes teeth to loose their bright color.

Precautions

Teeth whitening is not safe or effective for everyone, so a person should have a dental exam before starting treatment. The dentist can advise the patient about the most appropriate procedure. The oral health professional will also discuss the expected results of treatment. Patients may expect yellow or gray teeth to be replaced with a bright, white color. However, whitening may not work well on some stain colors.

The importance of a check-up

Whitening may not be recommended for people with gum disease, receding gums, or sensitive teeth. The dentist may advise against certain treatments if the enamel is worn. Enamel is the outer layer of the tooth. There is no enamel on an exposed tooth root, so the root cannot be whitened.

In addition, cavities must be filled before treatment begins. Otherwise, the patient could experience additional mouth sensitivity when treatment material comes into contact with decay or the tooth interior.

When whitening is not recommended

Women who are pregnant and nursing should avoid any whitening treatment except for toothpaste. Oral health care professionals advise that other treatments could contain levels of peroxide that are potentially dangerous to the child. Although no connections have been made between these treatments and harm to the child's health, mothers are urged to take preventive action and delay whitening treatment.

Teenagers should not have their teeth bleached until they are between 14 and 16 years old. In a younger child, the nerve of the tooth called the pulp chamber has not fully developed. Whitening at this point could irritate the pulp and cause sensitivity.

People who are allergic to peroxide should not be treated with this whitening agent.

Cautions about tooth color

Treatments such as bleaching are most effective on yellowish stains, according to the American Dental Association (ADA). Teeth with brown stains may not bleach as well, and the treatment is even less effective on gray-stained teeth.

Furthermore, bleaching will not change the color of tooth-colored fillings, dentures, crowns, porcelain restorations, bonding, or other material used to restore or replace a tooth. If bleaching is done, the newly whitened teeth will stand out in contrast to fillings or other modifications.

Description

Teeth are whitened by the use of bleach or other material. The treatment may be done in the dental office, at home with guidance from a dentist, or at home with the use of over-the-counter products. Tools for self-treatment include bleaching trays, gels or strips that are applied to the teeth, and toothpaste.

Whitening treatments are cosmetic procedures, and are usually not covered by dental insurance.

Products used by oral health professionals such and those sold over the counter may have the ADA Seal of Acceptance. This endorsement indicates that products carrying the seal have met the American Dental Association's criteria for safety and effectiveness. Those standards are based on the patient following directions when the product is used.

The ADA evaluation program is voluntary. That means manufacturers are not required to submit products for review. As a result, the lack of a seal may not indicate that the product is unsafe. However, products on the Accepted list have the ADA endorsement, and the association may take positions on certain unevaluated procedures such as laser treatment.

Dental office treatment

The whitening treatment provided by dentists is known as chairside bleaching, in-office bleaching, or power bleaching. The dentist first protects the patient's gums and tissue by applying a protective gel or a rubber shield. The dentist than applies a whitening solution on the teeth.

The whitening solution contains hydrogen peroxide, which is a bleaching agent that could change the tooth color. The bleach is used to remove surface (extrinsic) and deeper (intrinsic) stains. Professionally applied whiteners, those solutions used by dentists, usually contain hydrogen peroxide. This bleaching agent comes in concentrations ranging from 15% to 35%. As of March of 2005, all solutions with the ADA Seal had a 35% concentration of hydrogen peroxide.

After the gel is applied, a light may be shined on the teeth to accelerate the whitening agent. Some agents are enhanced by lasers. However, no treatments requiring lasers were on the ADA list of accepted products as of March 2005. Although lasers may be safe, the association had not seen published, peer-reviewed data on the safety and effectiveness of laser whitening.

Chairside bleaching treatment may last from thirty minutes to an hour, according to the ADA. In addition, patients may need to return for additional treatments. The cost of treatment for the whole mouth can cost from $500 to $1,000. Factors affecting cost include the patient's location and the number of treatments needed. At the high end of the range is laser treatment, which could cost $1,000 or more.

Dentist-supervised treatment

Supervised treatment combines visits to the dentist with treatment at home. The procedure is also called tray bleaching or nightguard bleaching because the patient wears a tray on the teeth that protects the gums from the whitening solution.

For this treatment, the dentist takes an impression of the patient's teeth and makes a mouthpiece tray, or mouthguard, that will fit over the teeth. The dentist dispenses a whitening gel that the patient will place in the customized mouthguard.

The gel usually contains carbamide peroxide, which comes in concentrations of 10%, 16%, and 22%. Products with the ADA Seal have a 10% concentration. That amount is the equivalent of an approximately 3% concentration of hydrogen peroxide. The ADA endorsement applies only to home systems dispensed by dentists. The association's Seal reflects the importance of consulting with a dentist before undergoing treatment at home, according to the ADA.

The dentist will set up a schedule for wearing the mouthguard. Wearing times vary by product. A patient may we ar the piece overnight for one to two weeks. For other systems, the patient wears the mouthguard for a set amount of time twice a day. This treatment usually lasts two weeks.

During supervised treatment, the dentist generally schedules appointments to monitor the patient's progress. In addition to checking the whitening process, the dentist may examine the fit of the mouthguard and look for signs of gum irritation.

Supervised home bleaching of the whole mouth costs from $300 to $600.

Over-the-counter (OTC) products

In-home treatments that can be purchased over-the-counter include products that use bleach in mouthguard trays as well as strips and gels. The bleaching agent is usually carbamide peroxide, which is not as strong as the hydrogen peroxide found in solutions that are used in chairside bleaching and supervised home treatment.

OTC treatments range in price from $20 to $150. Treatment lasts 14 days on average. Another treatment is the use of whitening toothpaste, a product that does not contain bleach.

TRAY TREATMENT. Mouthguard treatment kits can be bought in stores and over the Internet. The tray kits involve the use of a mouthguard and gel. While similar to dentist-supervised home treatment, the patient does not use a customized tray specifically for her or his mouth. Some kits have mouthguards that patients can mold to their teeth. However, the patient relies on the generic instructions provided by the manufacturer.

GELS AND WHITENING STRIPS. Gels are applied directly to the teeth. Whitening strips are thin, clear strips coated with a peroxide-based gel. The strips are applied to the teeth and worn for 30 minutes twice a day. Treatment time varies by product and generally lasts from five to 14 days.

WHITENING TOOTHPASTES. Whitening toothpastes do not contain bleach. Instead mild abrasives remove surface stains, but do not change tooth color. Products with the ADA Seal contain special chemicals or polishing agents that remove stains. A tube of whitening toothpaste costs about $5.

Preparation

The ADA advises people to consult with a dentist before beginning any teeth whitening treatment. The dentist can review the patient's oral health history and discuss the appropriate treatment. If necessary, the dentist will fill cavities.

Aftercare

During supervised at-home treatment, the dentist may schedule appointments to check on the progress of whitening, side effects, and the tray fit.

After treatment is completed, people need to be aware that smoking will cause teeth to discolor. Beverages with caffeine should be consumed with a straw to reduce the effects of staining. Another preventive action is brushing the teeth after drinking or eating foods that cause stains.

Risks

Teeth-whitening may cause sensitivity to hot and cold food and beverages. This is a temporary side effect that usually ends when treatment is completed. Some patients also experience gum irritation if the tray does not fit properly.

Normal results

Dentists use a stronger bleaching agent than that found in commercial products, so in-office whitening treatment produces a more dramatic effect on teeth with yellow stains. Over-the-counter products with bleach provide some change in the tooth color, and whitening toothpaste works only on surface stains.

Bleaching does not leave teeth permanently white. Whitening can last from six months to a year. Sometimes teeth stay white even longer. However, smoking or consumption of food and beverages that stain can cause discoloration within one month.

KEY TERMS

Enamel— The hard, white, outer layer of the tooth.

Fluoride— A compound believed to combat cavities in teeth.

Peroxide— A bleaching agent that is a compound consisting of two atoms of oxygen connected by a single bond.

Resources

PERIODICALS

Caruana, Claudia M. "The Smiles Have It!" Vegetarian Times, February 2003, 35-39.

Foley, Denise; Poust, Jenny. "Home Tooth-Whitening Kits." Prevention, February 2004, 160 (4 pages)[cited March 21, 2005]. 〈http://search.epnet.com/login.aspx?direct=true&db=hxh&an=11891865〉.

ORGANIZATION

Academy of General Dentistry. 211 East Chicago Avenue, Suite 900, Chicago, IL 60611-1999. 888-AGD-DENT (888-243-3368). 〈http://www.agd.org〉.

American Dental Association. 211 East Chicago Avenue, Chicago, IL 60611-2678. 312-440-2500. 〈http://www.ada.org〉.

American Dental Hygienists' Association. 444 North Michigan Avenue, Suite 3400, Chicago, IL 60611. 312-440-8927. 〈http://www.adha.org〉.

OTHER

"Teeth Whitening: Is it for you?" Academy of General Dentistry. December 20, 2004 [cited March 21, 2005]. 〈http://www.agd.org/media/2004/dec/whitening.asp〉.

"Tooth Whitening Systems." American Dental Hygienists' Association 2005 [cited March 21, 2005]. 〈http://www.adha.org/oralhealth/whitening.htm〉.

"Tooth Whitening Treatments." American Dental Association 2005 [cited March 21, 2005]. 〈http://www.ada.org/public/topics/whitening.asp〉.