What Is Tooth Bleaching
Tooth bleaching is one of the most conservative dental treatments for lightening natural teeth. There are two types of bleaching, vital and non vital. The word "vital" is used to describe any tooth which has a normal nerve and has not had endodontic therapy (commonly referred to as a root canal). Vital bleaching generally works best on teeth with uniform yellow or brown stains. Blue and gray stains are more difficult to remove and often stay behind after the yellow and brown color in a tooth are lightened. In addition, younger teeth bleach more quickly than older teeth.
Tooth Preparation
Generally, any leaking fillings are replaced prior to bleaching procedures. Bleaching will only lighten natural teeth and will have no effect on crowns or fillings. Any fillings which do not match after bleaching can be covered with a lighter filling material.
Types of Bleaching Procedures
There are two types of vital bleaching, one is called Office Bleaching since it is entirely done by the dental staff over a series of 30 to 60 minute bleaching appointments. The other is often called Home Bleaching since the application of the bleach is done at home by the patient. Both types of bleaching can work effectively.
Office bleaching generally involves placing a very strong bleach on the teeth for a short period of time. A rubber barrier is used to protect the soft tissues from bleaching chemicals.
Home bleaching uses a very mild bleach which is placed on the teeth daily by the patient with the use of a custom made tooth-tray. This allows the bleach to be applied for a longer period of time. The teeth slowly become lighter over a period of 4 to 8 or more weeks.
Due to its safety and lower cost, home bleaching is more commonly used as a first step treatment.
Home Bleaching
Procedure A custom plastic tooth tray is made for the patient's teeth to be bleached. This is given to the patient with home bleach and instructions for use.
The patient is usually instructed to place a drop of bleach in each tooth space in the tooth tray and to wear it during sleep or for 3-4 hours during the day for a period of 2 to 5 weeks. Patients refill the appliance every hour when used during the daytime, primarily after eating and before going to bed.
This usually produces an average shade lightening of two shades on the dentists tooth shade guide. The average time for optimal change is generally 3-6 weeks.
Limitations. The major limitations of this technique is that tooth lightening occurs slowly. With some patients, little change is seen until after 3 or 4 weeks of daily treatment while with others there is remarkable improvement sooner. However, home bleaching is generally more cost effective to the patient and is often the treatment of first choice.
Typical Results. Home bleaching, like office peroxide bleaching, works best on yellow, orange, or light brown stains. Effects are less dramatic with dark gray and blue stains and tetracycline banding, particularly in the gingival one-third. However, some improvement is possible even with severe tetracycline stains if treatment time is extended.
Because bleach is usually acidic it can increase discomfort in patients with dentin sensitivity. Patients with non sensitive exposed dentin surfaces will generally not have discomfort from home bleaching materials. However, if sensitivity starts during treatment it will often continue until treated with fluoride or sodium nitrate containing toothpastes (e.g. Denquel, Promise, or Sensodyne). However, for some patients, none of these will relieve sensitivity.
Safety. Almost all home bleaching materials have been classified by the FDA as oral antiseptics. The only noted side effect from ingesting large doses was a laxative effect from the glycerin in most of these materials.
Since a portion of home bleaching solutions is ingested, there have been concerns about its safety . Home bleaching solutions breaks down into hydrogen peroxide and urea. Hydrogen peroxide breaks down to water and oxygen. Urea, is safely excreted by the kidney.
Less than 10% of patients experience such complications as sensitivity to cold or sweets, soft tissue lesions, tissue sloughing, nausea, sore throat from swallowing the bleaching material, or jaw joint disorders from tray induced malocclusion.
With long term use of home bleaching teeth can sometimes appear chalky, a finding not observed with office bleaching or with home bleaching materials based on hydrogen peroxide.
Office Bleaching
Great care is taken to protect the gums and lips from the bleaching procedure. The process of bleaching natural teeth starts by isolating the teeth with a synthetic rubber device called a rubber dam. Then a strong hydrogen peroxide is applied to the teeth with a small piece of cloth. Heat is then applied for 30 minutes to 1 hour. The heat speeds up the time it takes for the bleach to work. Heat does not increase the degree of lightening and is kept at a level the patient finds comfortable. After the proper bleaching time has elapsed the teeth are thoroughly rinsed and a fluoride gel is applied to the teeth. The rubber dam is then removed.
Typical Results. Immediately after bleaching the teeth will appear very white. Much of this is from desiccation of the teeth. A day or two later the teeth will return to a normal color which should be whiter than before. The bleaching treatment may be repeated two, three, or more times if additional lightening in tooth shade is desired.
Limitations. One limitation of bleaching is that it is impossible to predict with any degree of accuracy, how much tooth lightening will occur with the process. It is possible no lightening will occur in some cases. However, we optimistically expect at least one to two shades of lightening after the completion of one or two bleaching treatments.
Complications. Occasionally bleach will come in contact with the gum or cheek tissues and can result in mild tissue irritation. During the bleaching process some discomfort is possible. Some patients experience sharp and intermittent shooting pains. Though uncomfortable, this is a benign symptom from the bleach working in the tooth. Following a bleaching session this discomfort is almost always gone within a day or two.
It is possible, though highly unlikely, that tissue burns, root canal treatment, or tooth loss could result from this, as with any other dental procedure. However, with bleaching procedures these problems are extremely rare.
Longevity of Vital Bleaching (Home or Office)
Bleaching is not permanent and the teeth will tend to get darker over time even though an initial lightening is usually achieved. The length of time bleaching lasts is highly variable from patient to patient. Generally speaking, we expect the lightening of the teeth to last about one year, after which the procedure may be repeated.
Overall Assessment.
All things considered, vital bleaching is the most safe and conservative method to lighten teeth. The procedure is often the treatment of choice for patients who wish to have a lighter and brighter smile.NonVital Bleaching Non-Vital bleaching is a very conservative dental treatment for lightening natural teeth. The word non-vital is used to describe any tooth which has had endodontic therapy (commonly referred to as a root canal). Non-Vital bleaching generally works best on teeth with uniform yellow or brown stains. Blue and gray stains are more difficult to remove and often stay behind after the yellow and brown color in a tooth are lightened. In addition, younger teeth bleach more quickly than older teeth.
There are a number of different techniques for bleaching non-vital teeth. The most popular and safest is referred to as a walking bleach.
Great care is taken to protect the gums and lips from the bleaching procedure. This process starts by isolating the teeth with a synthetic rubber device called a rubber dam. Next, the filling which was used to seal the root canal opening is removed.
The chamber where the nerve once was is cleaned and a mixture of strong hydrogen peroxide bleaching materials are placed into the tooth. A temporary filling is then placed and the patient is asked to return in one or two weeks. During the time the patient "walks around" between appointments, the bleaching material will slowly lighten the tooth.
Bleaching will only lighten natural teeth and will have no effect on crowns or fillings. Any fillings which do not match after bleaching may be replaced or covered with a lighter filling material.
After non-vital bleaching the teeth will appear lighter. In some cases the procedure is repeated one or more times until the desired result is achieved.
One limitation of non-vital bleaching is that it is impossible to predict with any degree of accuracy, how much tooth lightening will occur with the process. It is possible no lightening will occur in some cases. However, we optimistically expect at least one to two shades of lightening after the completion of one or two bleaching treatments.
Non-Vital bleaching is not permanent and the teeth will get darker over time even though an initial lightening is usually achieved. The length of time bleaching lasts is highly variable from patient to patient. Generally speaking, we expect the lightening of the teeth to last about one to two years, after which the procedure may be repeated.
All things considered, non-vital bleaching is the most safe and conservative method to lighten teeth which have had endodontic therapy.