What Is It?
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
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.
The most common reasons for yellowing or
stained teeth are aging, tobacco, tea and
coffee, which can stain the surface of the
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
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 —
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
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
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
Whitening is unlikely to cause serious
side effects, although some people;'s teeth
may become more sensitive temporarily. There
may be mild gum irritation as well.
Whitening procedures should not be done
while a woman is pregnant because the effect
of the whitening materials on the
development of the fetus is not known. Since
the procedure is cosmetic and option, it
should be postponed until after delivery.
When To Call A Professional
If you feel your teeth would benefit
from whitening, contact your dentist to
discuss the procedure.
American Dental Association
211 E. Chicago Ave.
Chicago, IL 60611
Phone: (312) 440-2500
Fax: (312) 440-2800
back to top