Tooth whitening is a procedure that lightens teeth and helps to remove stains and discoloration. Whitening is among the most popular cosmetic dental procedures because it can significantly improve the appearance of your teeth at much less cost and inconvenience than other techniques. The majority of dentists perform tooth whitening.
Every day, a thin coating forms on your teeth and it picks up stains. Also, the outer layer of each tooth, called the enamel, contains pores that can hold stains. Whitening is not a one-time solution. It will need to be repeated periodically if you want to maintain the brighter color.
What It’s Used For
The most common reasons for yellowing or stained teeth are aging, tobacco, tea and coffee, which can stain the surface of the teeth.
It is also possible to have stains that are inside the tooth. These are called intrinsic stains. For example, intrinsic stains can be caused by exposure to too much fluoride as a child while teeth are developing. Other causes include tetracycline antibiotics taken during the second half of pregnancy or given to children 8 years old or younger when the teeth are still developing.
Tooth whitening is most effective on surface stains caused by age, foods or drinks.
Cavities need to be treated before teeth are whitened because the whitening solution can penetrate decay and reach inner areas of the tooth, which can cause sensitivity. Also, whitening will not work on exposed tooth roots, because roots do not have an enamel layer. Receding gums can cause roots to become exposed. Whitening also does not work on crowns or veneers.
Whitening can be done in the dental office or at home. For in-office whitening, your dentist probably will photograph your teeth, which will help him or her to monitor how the treatment is progressing. Whitening in the office may involve two to six visits of approximately 45 minutes each. He or she also will examine your teeth and ask you questions to determine the type and severity of staining.
When the examination is complete, the dentist or a dental hygienist will clean your teeth. Once this is completed, the whitening procedure begins.
For whitening at home, your dentist will direct you to use custom trays that are made in the dental office and fit your teeth precisely. Home whitening usually takes two to three weeks. Over-the-counter kits also are widely available for home use. You should talk to your dentist about using these products, and use them according to directions to avoid overuse and possible damage to your teeth and mouth.
How It’s Done
There are two main types of whitening procedures. When whitening is done on a tooth that has had root-canal treatment and no longer has a live nerve, the process is called non-vital whitening. Vital whitening means that the procedure is being done on teeth that have live nerves.
Vital whitening may not improve the appearance of a tooth that has had root-canal treatment. If this is the case, your dentist will use a different procedure that whitens the tooth from the inside. He or she will place a whitening agent inside the tooth and will place a temporary filling. It will be left this way for several days. You may need this done only once, or it can be repeated until the tooth reaches the desired shade.
The most common type of vital tooth whitening involves placing a gel-like whitening solution, which usually contains hydrogen peroxides, in a tray that resembles a night guard or mouth guard. The tray is then placed over the teeth for a certain period of time — anywhere from an hour or two to overnight.
Tooth whitening can be done in the dentist’s office or at home. In-office whitening (also called chairside whitening) has the advantage of allowing your dentist to supervise the process — and your progress — more closely.
In-office whitening usually takes between 30 and 90 minutes and can require up to three appointments with your dentist. The number of visits required will depend on the type of discoloration and how white you want your teeth to be.
Your dentist will start by asking about your medical history to learn how your teeth became discolored. Different types of stains will respond differently to the treatment.
Your dentist will apply a special gel to the gums to protect them from the whitening agent. Then the whitening agent is applied. The most common substance used for chairside whitening is hydrogen peroxide.
Some whitening agents are activated by special lights or by heat. After the whitening agent is applied, the dentist will shine the light on your teeth for a short time. Some dentists have started to use lasers as a high-speed alternative to conventional whitening procedures. Consumers like the high-tech aspects of laser treatments, but the technology is still too new — and too expensive — to justify its general use. The American Dental Association states that while the technique may be safe, it has not seen published data on the safety or effectiveness of using lasers for tooth whitening.
If your teeth are badly discolored, you may need more extensive whitening than can be done in the office. Or you may decide you would prefer to whiten your teeth at home.
For in-home whitening, your dentist will take impressions of your teeth and will make one or two custom mouthpieces to fit you, depending on if you are having both upper and lower teeth whitened. It is important that the mouthpiece fit well so that the whitening agent remains in contact with your teeth and doesn’t irritate your gums. Over-the-counter mouthpieces are unlikely to fit correctly and can cause gum irritation if the whitening agent seeps out.
At home, you will fill each mouthpiece with a whitening gel your dentist provides, and wear the mouthpiece for several hours every day. Many people achieve the amount of whitening they want within a week or two, but you may need to wear the mouthpiece for four weeks or longer.
Your dentist may want to see you a few days after in-office whitening to check your gums. If your gums were exposed to the whitening agent, they can become irritated. If you are whitening your teeth at home, your dentist will want to check to make sure the process is working properly, usually after a week.
Whitening is not a permanent solution. The stains will come back. People who expose their teeth to a lot of staining may see the whiteness start to fade in as little as one month. Those who avoid staining foods and drinks may be able to wait six to 12 months before another whitening treatment is needed.
Re-whitening can be done in the dentist’s office or at home. If you have a custom-made mouthpiece and whitening agent at home, you can whiten your teeth as frequently as you want to. You should discuss your whitening schedule with your dentist, and talk about what whitening products would work best for you.