Teeth Whitening: Customize Your Bright,
White Smile
Transform your smile
with a customized teeth whitening
solution.
In the blossoming world of cosmetic
dentistry, teeth whitening reigns
supreme. Universally valued by men and women
alike, whitening (or bleaching) treatments
are available to satisfy every budget, time
frame and temperament.
Whether in the form of one-hour bleaching
sessions at your dentist's office, or
home-use bleaching kits purchased at your
local drugstore, teeth whitening solutions
abound. Yet only 15 percent of the
population has tried the cosmetic procedure,
and misinformation on the subject is rife.
The long and the short of it is that
teeth whitening works. Virtually everyone
who opts for this cosmetic treatment will
see moderate to substantial improvement in
the brightness and whiteness of their smile.
However, teeth whitening is not a permanent
solution and requires maintenance or
"touch-ups" for a prolonged
effect.
Bleaching vs. Whitening
According to the FDA, the term
"bleaching" is permitted to be
used only when the teeth can be whitened
beyond their natural color. This applies
strictly to products that contain bleach -
typically hydrogen peroxide or carbamide
peroxide.
The term "whitening," on the
other hand, refers to restoring a tooth's
surface color by removing dirt and debris.
So any product that cleans (like a
toothpaste) is considered a whitener. Of
course, the term whitening sounds better
than bleaching, so it is more frequently
used - even when describing products that
contain bleach.
Why Teeth Whitening? Examining Enamel
Most of us start out with sparkling white
teeth, thanks to their porcelain-like enamel
surface. Composed of microscopic crystalline
rods, tooth enamel is designed to protect
the teeth from the effects of chewing,
gnashing, trauma and acid attacks caused by
sugar. But over the years enamel is worn
down, becoming more transparent and
permitting the yellow color of dentin -
the tooth's core material - to show
through.
During routine chewing, dentin remains
intact while millions of micro-cracks occur
in the enamel. It is these cracks, as well
as the spaces between the crystalline enamel
rods, that gradually fill up with stains and
debris. As a result, the teeth eventually
develop a dull, lackluster appearance.
Teeth whitening removes the stains and
debris, leaving the enamel cracks open and
exposed. Some of the cracks are quickly
re-mineralized by saliva, while others are
filled up again with organic debris.
Tooth Discoloration: The Two Types of
Tooth Stains
There are two categories of staining as
it relates to the teeth: extrinsic staining
and intrinsic staining.
Extrinsic stains are
those that appear on the surface of the teeth
as a result of exposure to dark-colored
beverages, foods and tobacco, and routine
wear and tear. Superficial extrinsic stains
are minor and can be removed with brushing
and prophylactic dental cleaning. Stubborn
extrinsic stains can be removed with more
involved efforts, like teeth bleaching.
Persistent extrinsic stains can penetrate
into the dentin and become ingrained if they
are not dealt with early.
Intrinsic stains are
those that form on the interior of teeth.
Intrinsic stains result from trauma, aging,
exposure to minerals (like tetracycline)
during tooth formation and/or excessive
ingestion of fluoride.
In the past, it was thought that intrinsic
stains were too resistant to be corrected by
bleaching. Today, cosmetic dentistry experts
believe that even deep-set intrinsic stains
can be removed with supervised take-home
teeth whitening that is maintained over a
matter of months or even a year.
What Causes Tooth Staining?
Age: There is a direct
correlation between tooth color and age.
Over the years, teeth darken as a result of
wear and tear and stain accumulation.
Teenagers will likely experience immediate,
dramatic results from whitening. In the
twenties, as the teeth begin to show a
yellow cast, teeth-whitening may require a
little more effort. By the forties, the
yellow gives way to brown and more
maintenance may be called for. By the
fifties, the teeth have absorbed a host of
stubborn stains which can prove difficult
(but not impossible) to remove.
Starting color: We are
all equipped with an inborn tooth color that
ranges from yellow-brownish to greenish-grey,
and intensifies over time. Yellow-brown is
generally more responsive to bleaching than
green-grey.
Translucency and thinness:
These are also genetic traits that become
more pronounced with age. While all teeth
show some translucency, those that are
opaque and thick have an advantage: they
appear lighter in color, show more sparkle
and are responsive to bleaching. Teeth that
are thinner and more transparent - most
notably the front teeth - have less of the
pigment that is necessary for bleaching.
According to cosmetic
dentists, transparency is the only
condition that cannot be corrected by any
form of teeth whitening.
Eating habits: The
habitual consumption of red wine, coffee,
tea, cola, carrots, oranges and other
deeply-colored beverages and foods causes
considerable staining over the years. In
addition, acidic foods such as citrus fruits
and vinegar contribute to enamel erosion. As
a result, the surface becomes more
transparent and more of the yellow-colored
dentin shows through.
Smoking habits: Nicotine
leaves brownish deposits which slowly soak
into the tooth structure and cause intrinsic
discoloration.
Drugs / chemicals:
Tetracycline usage during tooth formation
produces dark grey or brown ribbon stains
which are very difficult to remove.
Excessive consumption of fluoride causes fluorosis
and associated areas of white mottling.
Grinding: Most
frequently caused by stress, teeth
grinding (gnashing, bruxing,
etc.) can add to micro-cracking in the teeth
and can cause the biting edges to darken.
Trauma: Falls and other
injuries can produce sizable cracks in the
teeth, which collect large amounts of stains
and debris.
Teeth Whitening options
Three major teeth whitening options are
available today. All three rely on varying
concentrations of peroxide and varying
application times.
In-Office Whitening
Significant color change in a short
period of time is the major benefit of
in-office whitening. This protocol involves
the carefully controlled use of a relatively
high-concentration peroxide gel, applied to
the teeth by the dentist
or trained technician after the gums have
been protected with a paint-on rubber dam.
Generally, the peroxide remains on the teeth
for several 15 to 20 minute intervals that
add up to an hour (at most). Those with
particularly stubborn staining may be
advised to return for one or more additional
bleaching sessions, or may be asked to
continue with a home-use whitening system.
Professionally Dispensed
Take-Home Whitening Kits
Many dentists
are of the opinion that professionally
dispensed take-home whitening kits can
produce the best results over the long haul.
Take-home kits incorporate an easy-to-use
lower-concentration peroxide gel that
remains on the teeth for an hour or longer
(sometimes overnight). The lower the
peroxide percentage, the longer it may
safely remain on the teeth. The gel is
applied to the teeth using custom-made
bleaching trays that resemble mouth guards.
Over-the-Counter Whitening
The cheapest and most convenient of the
teeth whitening options, over-the-counter
bleaching involves the use of a store-bought
whitening kit, featuring a bleaching gel
with a concentration lower than that of the
professionally dispensed take-home
whiteners. The gel is applied to the teeth
via one-size-fits-all trays, whitening
strips or paint-on applicators. In many
cases this may only whiten a few of the
front teeth unlike custom trays that can
whiten the entire smile.
Hydrogen Peroxide vs. Carbamide Peroxide
The bleach preference for in-office
whitening, where time is limited, is
powerful and fast-acting hydrogen peroxide.
When used in teeth bleaching, hydrogen
peroxide concentrations range from
approximately nine percent to 40 percent.
By contrast, the bleach of preference for
at-home teeth whitening is slower acting
carbamide peroxide, which breaks down into
hydrogen peroxide. Carbamide peroxide has
about a third of the strength of hydrogen
peroxide. This means that a 15 percent
solution of carbamide peroxide is the rough
equivalent of a five percent solution of
hydrogen peroxide.
How White Can You Go? A Matter of
Esthetics
Teeth whitening results are subjective,
varying considerably from person to person.
Many are immediately delighted with their
outcome, while others may be disappointed.
Before you embark on any whitening
treatment, ask your dentist for a realistic
idea of the results you are likely to
achieve and how long it should take to
achieve them. Expectations play a major role
in teeth whitening.
Whitening Shade Guides
In the dental office, before-and-after
tooth color is typically measured with shade
guides. These are hand-held displays of wide
ranges of tooth colors. (Dentists also use
them in choosing crown and other restoration
shades.)
The standard-setter among them has long
been the Vitapan Classic Shade Guide. This
shade guide standard incorporates 16 shades,
systematically arranged from light to dark
into four color groups, and provides a
universal tooth-color terminology.
While whitening can occasionally lighten
tooth color by nine or more shades, most of
those who bleach their teeth are likely to
see a change of two to seven shades.
Teeth Whitening Risks
Teeth whitening treatments are considered
to be safe when procedures are followed as
directed. However, there are certain risks
associated with bleaching that you should be
aware of:
- Sensitivity:
Bleaching can cause a temporary increase
in sensitivity to temperature, pressure
and touch. This is likeliest to occur
during in-office whitening, where
higher-concentration bleach is used.
Some individuals experience spontaneous
shooting pains ("zingers") down the
middle of their front teeth.
Individuals at greatest risk for
whitening sensitivity are those with gum
recession, significant cracks in their
teeth or leakage resulting from faulty
restorations. It has also been reported
that redheads, including those with no
other risk factors, are at particular
risk for tooth sensitivity and zingers.
Whitening sensitivity lasts no longer
than a day or two, but in some cases may
persist up to a month. Some dentists
recommend a toothpaste containing
potassium nitrate for sensitive teeth.
- Gum irritation: Over
half of those who use peroxide whiteners
experience some degree of gum irritation
resulting from the bleach concentration
or from contact with the whitening
trays. Such irritation typically lasts
up to several days, dissipating after
bleaching has stopped or the peroxide
concentration lowered.
- Technicolor teeth:
Restorations such as bonding, dental
crowns or porcelain veneers are not
affected by bleach and therefore
maintain their default color while the
surrounding teeth are whitened. This
results in what is frequently called
"technicolor teeth."
Maintaining Your Whiter Smile
To extend the longevity of newly whitened
teeth, dentists are likely to recommend:
- At-home follow-up or maintenance
whitening - implemented immediately or
performed as infrequently as once a
year.
- Avoiding dark-colored foods and
beverages for at least a week after
whitening.
- Whenever possible, sipping
dark-colored beverages with a straw.
- Practicing excellent oral hygiene -
brushing and flossing after meals and at
bedtime.
Caveats
In addition to the aforementioned risk
factors, a number of caveats should be
considered before undergoing teeth
whitening:
- No amount of bleaching will yield
"unnaturally" white teeth.
- Whitening results are not fully seen
until approximately two weeks after
bleaching. This is an important
consideration if you are about to have
ceramic restorations and want to be sure
the color matches that of your newly
bleached teeth.
- To avoid the technicolor effect,
tooth-colored restorations will likely
need replacement after bleaching.
- Recessed gums often reveal their
yellowish root surfaces at the gum line.
That yellow color has proven difficult
to bleach.
- Pregnant or nursing women are advised
to avoid teeth whitening. The potential
impact of swallowed bleach on the fetus
or baby is not yet known.
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