Tooth Whitening Methods

Professional Tooth Whitening

There are two main methods of tooth whitening or tooth bleaching. The first involves applying a high concentration of oxidizing agent for a short period of time, which is the so-called office bleach. This produces quick results but risks chemical burns to the soft tissues. Therefore, most in-office bleaching procedures use a light-cured protective layer that is carefully painted on the gums and papilla (the tips of the gums between the teeth). The bleaching agent is either carbamide peroxide, which breaks down in the mouth to form hydrogen peroxide, or hydrogen peroxide itself. The bleaching gel typically contains up to 35% hydrogen peroxide equivalent.

When teeth start to age they tend to turn yellow.  This and other sorts of stains can be removed by whitening processes.  There are at home bleaching processes that take anywhere from three to six weeks, depending on the stain.  The carbamide peroxide level is about 10% to 22% and is used in a custom tray that should be worn twice a day for one hour.  Bleaching done by a dentist has a much stronger carbamide peroxide level, which can range from 34% to 44%.  Because of such a high level of carbamide peroxide only a professional should do this process.  Power bleaching is the most powerful form of bleaching that is still used today.  This has the highest level of peroxide (30% to 50%.)  It is used for those with severe discoloration.  This type of bleaching takes about 35 minutes depending of the stain.  Power bleaching lasts anywhere from one to seven years, depending on personal habits.
 

Home Tooth Whitening

The alternative method involves using a thin mouthguard or strip to hold a low concentration of oxidizing agent next to the teeth for as long as several hours a day for a period of 5 to 14 days. This is known as take-home or over-the-counter bleaching. This is a slower process but has fewer risks to the soft tissues. The bleaching agent is typically less than 10% hydrogen peroxide equivalent.

A typical course of bleaching can produce dramatic improvements in the cosmetic appearance of most stained teeth; however, some stains do not respond to bleaching. Tetracycline staining may require prolonged bleaching, as it takes longer for the bleach to reach the dentine layer. White-spot decalcifications may also be highlighted and become more noticeable. Bleaching is least effective if your teeth have white spots, decay or infected gums. It is also least effective when the original tooth color is grayish. Bleaching is most effective with yellow discolored teeth.

Recently, efforts have been made to accelerate the bleaching process by the use of light. Studies have shown varying results as to the efficacy of light-activated bleaching.

Side effects of tooth bleaching include: chemical burns (if a high-concentration oxidising agent contacts unprotected tissues, which may bleach or discolor mucous membranes), sensitive teeth, and overbleaching (known in the profession as "over white teeth"). Rebound, or teeth losing the bleached effect and darkening, is also an issue, with some studies showing the rebound effect over 30 days. A recent study by Kugel et al has shown that as much as 4 shades of lightness can be lost over 30 days with light-activated/office bleaching.

Tooth Whitening - Internal Bleaching

Internal bleaching procedures are performed on devitalized teeth that have undergone endodontic therapy but are unesthetic due to internal staining of the tooth structure by blood and other fluids that leached in

As you can see there are many ways to whiten teeth.  You can bleach your teeth at home or have them bleached by the dentist.  These are just some of the tooth whitening processes.