Cosmetic dentistry

Along with your eyes, your smile is the first thing a person notices when meeting you. So, when you hesitate to smile because of broken, discolored, or poorly spaced teeth, you may be sending an unintended negative message. But many people are finding they don't have to hide their teeth any longer. With the advent of different materials and treatments, a better smile is now within reach for millions of adults.

Teeth whitening

According to the Academy of General Dentistry, tooth whitening is a $600 million industry that is growing by 15%–20% each year. In addition to the whitening procedures performed under the supervision of a dentist, drugstore and supermarket aisles overflow with whitening remedies.

Whitening products fall into two main categories: those that contain peroxide, which actually changes the natural color of the tooth, and others, such as whitening toothpastes, that remove surface stains using polishing or chemical agents and mild abrasives. Because whitening toothpastes don't change the color of teeth, their effects are more subtle than bleaches. This section focuses on products containing peroxide.

Bleaching, or whitening of the teeth using peroxides, is available both through your dentist and in several types of over-the-counter products. The American Dental Association recommends you consult with your dentist before using a bleaching product, even an over-the-counter one. That's because bleaching can be uncomfortable for people with sensitive teeth or an exposed root. Also, because most products only bleach natural teeth, if you have tooth-colored fillings, crowns, veneers, or dentures, bleaching may leave some areas whiter than others. In addition, your dentist can evaluate whether bleaching is right for your teeth, since different kinds of discoloration respond differently to whitening.

Most bleaching is not permanent, so keeping your teeth pearly white means repeating the bleaching process regularly. How long a bleaching treatment lasts depends upon which method you choose (see Table 6) and on how well you take care of your teeth, whether you smoke, and what you eat and drink.

Table 6: Common over-the-counter teeth-whitening kits
Product	How it is used	How often it is used	Main active whitening ingredient	How long manufacturer claims effects last
Rembrandt Whitening Pen	Apply gel to teeth	Once per night for 14 days	Hydrogen peroxide	Up to 6 months
Crest Night Effects Whitening Gel	Paint gel on teeth	Once per night for 14 days	Sodium carbonate peroxide	Up to 6 months
Crest Whitestrips	Apply strips to teeth	Twice per day for 30 minutes each; repeat for 7, 10, or 14 days depending on type of kit	Hydrogen peroxide	12 months
Rembrandt Whitening Strips	Apply strips to teeth	Once per day for 30 minutes; repeat for 5 days	Hydrogen peroxide	Up to 6 months
Klear Action Whitening Light system	Rinse teeth; paint on gel; shine activating light on teeth	10–20 applications (under 5 minutes each)	Urea peroxide	Up to 6 months

Dentist-supervised bleaching

Your dentist can perform a bleaching process in the office or prescribe a procedure for you to do at home.

Chair-side bleaching. Your dentist begins a whitening treatment by applying a protective gel or rubber shield to your gums to protect them from the bleaching agent. Your dentist etches your teeth with an acid solution and then applies an oxidizing agent to the enamel. Your teeth are exposed to a bright light or a laser to hasten the lightening. It usually takes three to four sessions, each lasting about 30–60 minutes, to achieve the color you want. Chair-side bleaching can offer more uniform results than at-home bleaching methods. A newer technique, called power bleaching, uses a highly concentrated form of hydrogen peroxide as the lightening agent. It can deliver results in just one session. Your teeth will darken again within one to three years, and you may need to repeat the procedure. Costs vary, with some dentists charging between $100 and $250 a session and others charging a single fee of $250 to $400 per arch (upper or lower teeth).

Bleaching pulp-damaged teeth. When the pulp is dead or injured, a tooth will darken. To correct this problem, your dentist can rinse the pulp chamber with a bleaching agent while performing root canal therapy. If the stain persists or the tooth darkens after the root canal procedure is completed, your dentist can reopen the pulp chamber and fill it with bleach for several minutes under a heat light. This process may have to be repeated several times. Alternately, the dentist can fill the pulp chamber with bleaching solution and cover it with a temporary filling. In this case, you'll need to return after a few days to have the bleach removed and the tooth permanently sealed. Costs vary; some practices charge between $300 and $600 per tooth.

Home bleaching (dentist prescribed). To enable you to do the bleaching at home, your dentist makes a custom-fitted mouthpiece to hold the bleaching chemicals (carbamide peroxide or hydrogen peroxide). Then you spread the chemicals into the mouthpiece and put it on for the recommended period (between 30 minutes and several hours) each day for a week or two. Some users report tooth sensitivity during the treatment, but it usually subsides once the treatment is complete. This procedure generally costs between $250 and $400 per arch (upper or lower).

Over-the-counter bleaching kits

All of the following products contain some kind of peroxide as their active ingredient and, therefore, actually change the natural color of the teeth. The bleaching agents in these products usually aren't as strong as the chemicals found in the products administered by a dentist.

Whitening strips. Whitening strips are thin, flexible pieces of plastic applied directly onto the teeth. After the specified amount of time, usually 30 minutes either once or twice a day, the strips are peeled off the teeth. This process is repeated for between 5 and 14 days. In general, the strips designed for use over a shorter number of days contain a higher concentration of the peroxide ingredient than those intended to be worn over a longer number of days.

Gels. The main difference among the gels is how they are applied to the teeth. Some are applied with a small paintbrush, while others come in a pen-like applicator. Generally, the gel is applied before you go to bed and left on, and is used for about two weeks.

Combination gel and light. One whitening system, called Klear Action, involves three steps: You use an acid rinse, apply a whitening gel, and hold a special light up to your teeth for two minutes to "trigger" a whitening ingredient in the gel.

Whitening rinses. A whitening rinse from Listerine promises whiter teeth in 12 weeks. Simply rinse with the product for 60 seconds twice a day before brushing.

Which method is right for you?

Unfortunately, there is no simple answer. It isn't clear which bleaching method is the most effective. An analysis of studies that compared at-home whitening products (dentist dispensed and over-the-counter) with placebos and with each other found that whitening products are effective. The analysis, conducted by the independent Cochrane Collaborations, found differences among the products, primarily because of varying levels of the active ingredients. But they didn't recommend one product over another, because they found that most of the existing studies on whiteners were sponsored or conducted by the makers of whitening products and thus were not very reliable. The researchers concluded that more independent studies are needed. They also suggested that consumers be made more aware of side effects such as tooth sensitivity and gum irritation.

One advantage of over-the-counter bleaching methods is that they cost far less than techniques offered by dentists. On the other hand, as of 2007, none of the over-the-counter bleaching products carry the ADA Seal of Acceptance, while several bleaches used by dentists do carry the seal.

Some Internet companies sell materials to make a bleaching tray for use at home. However, according to the Academy of General Dentistry, trays can cause gagging, gum irritation, or damage to existing dental work if not properly fitted and supervised by a dentist.

There is not yet enough information to determine the long-term safety of whitening products. Therefore, they are not recommended for children under age 16, women who are pregnant or breast-feeding, people with sensitive teeth or an allergy to peroxide, or those with gum disease or worn tooth enamel.

Bonding

Bonding involves applying a tooth-colored composite resin to the surface of the teeth to correct chips, cracks, or tooth spacing, or to get rid of stubborn stains. First, your dentist treats your teeth with acid to make them more receptive to the resin. Next, he or she applies a thin coat of the bonding material to the tooth and hardens it using a light or a chemical solution. Additional coats of resin can be applied to fill gaps and lengthen teeth. Finally, the dentist polishes the tooth. The whole procedure can be accomplished in one visit. The cost of bonding depends on the size and complexity of the site being repaired.

Veneers

Veneers also alter the tooth's color, shape, and surface. They can be used to cover stained or chipped teeth, camouflage gaps and spaces, and make crooked teeth appear straighter without orthodontic treatment. These thin shells are prefabricated in a laboratory based on an impression your dentist makes of your mouth. Veneers can be formed out of porcelain, acrylic, or composite resin. Porcelain generally provides the best looking and longest lasting veneer.

Installing a veneer takes two appointments. On the first visit, your dentist will pare down the enamel so the added thickness of the veneer does not affect your bite. Next, he or she makes a mold of your teeth, which is used to craft the veneer in a dental laboratory. On your next visit, the dentist etches the surface of the enamel and attaches the veneer using a thin coat of composite resin.

Veneers are subject to chipping, but you can count on them lasting up to 10 years if you avoid activities that are likely to break them, including biting hard objects and chewing ice. Veneers cost between $1,000 and $1,300 per tooth.

Tooth reshaping

Minor imperfections in tooth length, contour, and shape can be remedied by removing small amounts of enamel from the surface and sides of the tooth. Your dentist can also correct signs of wear and tear, such as chips, grooves, and ground-down edges. Recontouring is often done in conjunction with bonding. Some people experience tooth sensitivity for a brief period after the procedure. Individuals with thin enamel are not good candidates for this technique. The process can cost between $200 and $400 per tooth.

Crown lengthening

Sometimes teeth appear "too short" because there is excessive gum tissue around their bases. This problem can be corrected with a type of minor gum surgery called gingivectomy. The crown of the tooth is made to appear longer by trimming or reshaping the gum and bone to expose more of the tooth enamel. The gum line can also be trimmed to produce a more even appearance. The procedure also has therapeutic uses. A dentist may need to remove gum tissue before repairing a tooth that is broken or decayed below the gum line or installing a crown or bridge.

Review Date: 2007-04-01

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