Teeth Whitening

Choosing a tooth whitening product
You may have seen or read about tooth whiteners in magazine and newspaper ads, televised "infomercials" and radio announcements. But how do you know which product is right for you?

Peroxide-containing Whiteners or Bleaching Agents
These include products that are dentist-dispended for home use, administered in the dental office, or purchased over-the-counter for home use.

I. Home-Use Whiteners
Home-use whiteners dispended by dentists usually contain 10 percent carbamide peroxide (the most commonly used active ingredient in home-use bleaching products), which is equivalent to about 3 percent hydrogen peroxide. Currently, all of the home-use whiteners that have the ADA Seal of Acceptance contain 10 percent carbamide peroxide, although this concentration is not a requirement of the program.

Although bleaching agents are available over-the-counter, the ADA Seal of Acceptance program considers only those dispended by a dental office. That's because professional consultation by a dentist is important to the whitening procedure's safety and effectiveness.

Clinical data on 10 percent carbamide peroxide continue to support both its safety and effectiveness. In a water-based solution, carbamide peroxide breaks down into hydrogen peroxide and urea, with hydrogen peroxide being the active bleaching agent. Other ingredients of peroxide-containing tooth whiteners may include glycerin, carbopol, sodium hydroxide and flavoring agents.

The most commonly observed side effects to hydrogen or carbamide peroxide are tooth sensitivity and occasional irritation of the soft tissues in the mouth, particularly the gums. Tooth sensitivity often occurs during the early stages of bleaching treatment, but usually lessens as the treatment continues. Tissue irritation, in most cases, results from an ill-fitting tray rather than the tooth-bleaching agents. Both of these conditions usually are temporary and stop after the treatment.

II. In-office Whitening
In-office (chairside) whitening is done in the dental office. There are many professionally applied tooth whitening bleach products available to dentists. These products contain hydrogen peroxide in concentrations ranging from 15 percent to 35 percent. They are sometimes used with a light or laser, which reportedly accelerates the whitening process. Currently, all of the professionally applied whiteners that have the ADA Seal of Acceptance contain 35 percent hydrogen peroxide, although this concentration is not a requirement of the program.

While home-use products often are intended for use over a two-to-four week period, the in-office procedure is usually completed in about one hour. To help protect the mouth, the patient's gum tissues are isolated either with a rubber dam or a protective gel.

As with the 10 percent home-use carbamide peroxide bleach products, the most commonly observed side effects of professionally applied hydrogen peroxide products are temporary tooth sensitivity and occasional irritation of oral tissues. On rare occasions, irreversible tooth damage has been reported.

Whitening Toothpastes
Several whitening toothpastes (dentrifices) that are available over-the-counter have received the ADA Seal of Acceptance. Whitening toothpastes in the ADA Seal of Acceptance program contain polishing or chemical agents to improve tooth appearance by removing surface stains through gentle polishing, chemical chelation, or some other non-bleaching action. Whitening toothpastes should not be expected to provide the same level of whitening as a bleach product.

Special Considerations
It may be difficult to whiten some teeth. If your teeth are naturally yellow or have brown stains from tetracycline use, your dentist may recommend other options such as bonding, crowns or veneers to improve your smile.

If you have several fillings, crowns, and extremely dark stains, talk to your dentist about which tooth whitening method and product is right for you. A thorough oral examination is essential to determine if bleaching is an appropriate course of treatment. Your dentist then can monitor the treatment plan.

Your dentist may suggest the at-home method, where you lighten your teeth at a time that is convenient for you. The dentist will prescribe a whitening gel and provide special bleaching trays to fit your mouth. The gel is placed in the bleaching tray and worn during the day or in the evening for a certain period of time specified by the dentist.

What to Expect
Dentists usually bleach teeth a shade lighter than the desired color because they may darken with time. For a few days following treatment, your teeth may be sensitive to temperature extremes or the gums may experience mild irritation. If this persists, see your dentist.

Be aware that newly whitened teeth may more readily absorb stains. It is a good idea to avoid stain-causing beverages (such as coffee, tea, red wine) for several days after the procedure.

Some patients with certain dental conditions may not be good candidates for bleaching. Those with gum recession and exposed, highly sensitive root surfaces may find the whitening ingredients further irritate their teeth. Your dentist can advise you about which method is right for you.

If you avoid tobacco and large quantities of stain-producing foods, your teeth may remain lightened for several years, after which the whitening process may need to be repeated.

Brushing twice a day, flossing or using an interdental cleaner once a day, and regular dental visits and cleanings will help keep your teeth healthy and bright.

WHITEN YOUR SMILE - The Questions Behind Tooth Whitening
There are many causes behind tooth staining. Certain medicines, tooth trauma, root fillings, and even foods and beverages can cause tooth discoloration over time. Some discolorations are superficial while others are internal. However, both can be effectively treated by a dentist. Professional whitening is the best option to safely lighten discolored teeth.

How does bleaching work?
The whitening process is possible "due to the ability of the carbamide peroxide and hydrogen peroxide to freely pass through enamel and dentin and to permeate to all parts of the tooth." These peroxides break down into oxygen radicals, which then migrates between the enamel prisms, breaking down any colored molecules that result in tooth discoloration. The structure of the tooth is not altered; the internal tooth color is simply made lighter.

"Bleaching agents breaks down into tiny molecules and move in all directions so even if the entire tooth is not covered with bleach, the entire tooth is whitened."

Numerous studies have proven the effectiveness of peroxides in whitening teeth. Enamel, dentin, existing fillings, and binding materials are not affected by the whitening agents, nor are they harmed by the whitening materials.

Will bleaching affect bond strength?
Even though bleaching agents release a great amount of oxygen into the tooth, existing bonds are not weakened."

If one is planning to bleach first and then bond, a period of 7-10 days should elapse after the bleaching before bonding is attempted, due to the high concentration of oxygen in the tooth, which could significantly and adversely affect polymerization of the resins.

How long does the bleaching last?
Bleaching results are very stable. However, depending on the patient's nutrition and lifestyle habits, bleaching may need to be redone periodically. Due to the safety of the bleaching agents, this should not cause concerns to the dentist or patient.

Will bleaching cause tooth sensitivity?
Tooth sensitivity is a common side effect of bleaching. This sensistivity is transient and disappears after the completion of bleaching. However, Opalescence products are available with PF desensitizing agents already in them. Research has shown that "just as hydrogen peroxide penetrates through the enamel and dentin and to the pulp, so does potassium nitrate. Fluoride acts primarily as a tubular blocker, plugging the holes and slowing down the fluid flow that causes the sensitivity. Potassium nitrate acts more like an analgesic or anesthetic by keeping the nerve from repolarizing after it has depolarized in the pain cycle. Therefore, there are tow mechanisms of action - one affecting fluid flow and the other a direct effect on the nerve."

Will bleaching cause problems by weakening the tooth's enamel?
Findings on the Opalescence PF product line presented at the American Association of Dental Research confirm that whitening with Opalescence PF will actually minimize sensitivity, provide anti-caries benefits, increase enamel microhardness, and improve overall enamel health.

Important: Whitening treatments should only be done under dental supervision!
Tooth whitening treatments today are effective/efficacious and safe, if they are used appropriately and with the correct materials. This includes an initial diagnosis, professional teeth cleaning, briefing on the whitening process to be used, and then monitoring of the patient during the treatment phase. Self-treatment by the patient with over-the-counter (OTC) products can pose risks for the teeth and gums, and often does not provide the results desired. Therefore, all products of the Opalescence system are medical products, and are dispensed or released only by dental practitioners.