Encyclopedia / T / Teeth Bleaching

Teeth Bleaching


Article updated and reviewed by Micheal Kapner, DDS, Editor--Bulletin Ninth District Dental Association. Editorial review provided by VeriMed Healthcare Network on July 26, 2005.

Teeth bleaching can be defined as: The whitening (or lightening) of a single tooth or multiple teeth via the application of an external agent or agents.


Teeth bleaching, or whitening, can be achieved by either “over-the-counter” methods, or by seeing your dentist. The latter is known as professional bleaching, and in most cases offers stronger, more predictable results.

“Over the counter” techniques offer a variety of gels, liquids, toothpastes, and “do-it-yourself” kits. While usually more affordable than having your teeth professionally whitened, the results may vary greatly, and in many cases, only marginal differences can be observed.

Professional whitening offers a number of choices to people as well. There is internal bleaching, as well as external bleaching. Internal bleaching is used mostly to lighten one tooth at a time. The tooth is usually much darker than the other teeth in the mouth. This is typical for non-vital, or “dead” teeth, where root canal therapy has been performed in the past. In this case, a small cotton pellet saturated with a concentrated bleach solution (a minimum of 35 percent hydrogen peroxide) is sealed inside the tooth anywhere from a few days up to a week. Sometimes, a special light is fixed on the tooth to speed up the process.

When full arch external bleaching is requested (and indicated), the dentist can offer two choices – take-home or in-office. Take home bleaching is more common, and usually more affordable. In this case, the dentist will take impressions (molds) of each arch, pour stone models of the teeth, and make custom trays for the patient to wear. These custom trays are made from a clear, rubberized material, and they serve to hold the bleaching material (or gel in most cases) on the teeth. This optimizes treatment by keeping the bleaching material where it should be – on the teeth - and away from where it should not be – on the gums – thus reducing sensitivity and irritation.

In-office bleaching is usually more expensive than the take-home alternatives. However, there are advantages to this technique that may well justify the increase in cost. Speed, convenience, and outcome predictability are the main advantages to in-office bleaching. Most cases see a dramatic change (nine to 10 shades lighter) in about an hour. This is compared to similar changes that could take up to two weeks using the take-home technique. This speed of treatment is not only convenient for a multitude of reasons, but also leads to more predictable results. Each step of the bleaching process is monitored and controlled by the dental professional. There are no compliance issues (such as not wearing the trays every night, not smoking, or not drinking red wine during the bleaching process) which could lead to less than optimal results.

In-office bleaching requires the patient to sit in the dental chair for about an hour. First, the teeth are isolated with a liquid dam. This isolation process is done to not only keep the bleaching material on the teeth, but just as importantly, to keep the material away from the gum tissue as well. Once the teeth are isolated, and the gums are protected, the dental professional applies the bleaching agent (or gel) to all the teeth being bleached. After this is complete, the dentist will place special, protective glasses over the patient’s eyes. Once everything is in place, the bleaching light is positioned in front of the teeth and activated. During the process, the dental professional will check on the patient to make sure that he or she is tolerating it without complication. At the end of the process, the bleaching gel (which is usually re-applied up to three or four times) is rinsed away, and a fluoride paste is applied. This is used to decrease post-operative sensitivity. The patient is then sent home with post-care instructions; restrictions might include abstaining from: smoking, citrus beverages, fruits, red wine, or highly staining liquids for up to two weeks. The final shade of the teeth is usually noted in about two weeks post-treatment, and is noted in the patient’s chart at the follow-up visit. For optimal results, and in order to maintain whiteness, it is recommended that touch-up kits be used every 12 to 18 months.


Can the teeth be treated and whitened?

Does it hurt or damage the teeth in any way?

Can it be done at home?

Which product would you recommend?

Should I do veneers or caps instead of bleaching?

How much does it cost?

Would a whitening toothpaste help?