crown, commonly referred to as a “cap”, is a
tooth-shaped covering placed over a damaged
tooth to restore its shape, size, strength or to
improve its appearance.
drills, the tooth is first reduced in size and
then the dental crown is cemented on to encase
the tooth above the gums. Dental crowns are made
of metal and/or ceramic porcelain.
When are crowns required?
majority of a tooth’s surface becomes an issue,
but the root structure is of good health, a
dental crown is often recommended. What sort of
circumstances does this include?
|Porcelain crown was
used to fix the fractured tooth seen in
the top row. Large restorations that
were failing were replaced with
porcelain-fused-to-metal dental crowns
in the bottom row.
worn down beyond simple repair. This can
result from general use over a lifetime, teeth
grinding while asleep (bruxism), or from acid
foods that dissolve away the enamel (erosion).
that is too large to fill with dental material.
If dental decay grows too large, there will not
be enough sound tooth structure to hold a
filling in place – a dental crown may hold
Misshapen or discolored tooth needing coverage.
Cosmetic dentists often place crowns on
unaesthetic teeth to mask irregularities.
tooth needing support. Various reasons can
lead to a tooth being weakened and prone to
fracture – one prevention technique is to place
a dental crown.
needed for dental bridge. A bridge holds an
artificial tooth in the space of a missing tooth
by attaching onto nearby natural teeth. The
natural teeth are given crowns and the
artificial tooth is welded to them.
Types of dental crowns
two main types of dental crowns: temporary
and permanent. Permanent crowns are what
most people know as dental crowns or caps.
As the name
suggests, temporary crowns are intended
for short-term use only. Temporary crowns are
made from plastic resin during the appointment,
are bonded to the tooth with temporary cement
(so they can be removed at a later date), and
are used in all sorts of dental treatments. Many
treatments require that the patient leave the
dental office with a drilled tooth while the
dental laboratory makes the final dental
appliance. Since the patient cannot leave the
clinic with drilled teeth, temporary crowns are
made that fit over the tooth to provide normal
appearance and function for the patient. Once
the final prosthesis is fabricated, the
temporary crown is removed and the final product
Permanent crowns are similar to the
temporary crown, but made of different material
and with more care. Instead of plastic resin,
permanent crowns are made from metal and/or
porcelain to provide a more natural appearance
and last for decades. Unlike temporary crowns,
the permanent variety are fabricated at a dental
laboratory (not beside the dental chair) and
placed in the mouth at the next appointment.
|All porcelain crown
(top), all metal gold crown (middle) and
porcelain-fused-to-metal crown (bottom).
Permanent crowns are made from one of three
types of material: all metallic, all porcelain,
or porcelain-fused-to-metal. Each has its
advantages and disadvantages that you need to be
aware of prior to making your decision.
metallic crowns are made from gold or other
metal alloys, such as palladium or
nickel-chromium. Metallic crowns have many
advantages over other crown types; they wear
down opposing teeth less, withstand biting and
chewing forces best, rarely chip or break and
less tooth structure needs to be removed for
them to fit the tooth. Unfortunately, they are
metallic in color but are a great choice for
back teeth such as molars that are rarely seen
when you smile or speak.
All-ceramic or all-porcelain dental crowns
provide the best natural color match than any
other crown type and may be more suitable for
people with metal allergies. However, they are
not as strong as porcelain-fused-to-metal crowns
and they wear down opposing teeth a little more
than metal or resin crowns. All-ceramic
crowns are a good choice for front teeth, but no
matter what your dentist tells you, modern
all-porcelain crowns cannot withstand the
demands of being placed on molar teeth.
popular choice for dental crowns is the
middle-road option of
porcelain-fused-to-metal crowns. They can be
color matched to look like natural teeth (unlike
all metallic crowns), however they do not wear
down opposing teeth, chip or break like
all-ceramic crowns. However, sometimes the metal
underlying the crown's porcelain can show
through as a dark line, especially at the gum
line and even more so if your gums recede. These
crowns can be a good choice for front or back
Dental crown procedure
dental crown procedure usually runs along two
dental appointments spaced a week or two apart.
During the first appointment you are clinically
assessed and the tooth is prepared. After the
dental laboratory has fabricated your crown, it
will be fitted and inserted in the second
first visit, (1) your dentist will use
x-rays and other methods to assess the roots of
the tooth receiving the crown. This is to ensure
that the roots are healthy – there is little
point in placing an expensive crown on a tooth
that fails a few months or years later because
the roots were too weak to support it. A root
canal treatment may be performed first if your
tooth is decayed and there is a risk of
infection to the tooth’s pulp.
dentist will provide local anesthetic to numb
any sensation to the tooth and nearby gum
tissue. The tooth is then wedged to separate it
from nearby teeth, and (2) its surface is
systematically reduced using various drilling
burs. This reduction in enamel is to ensure that
there is room for the future dental crown. The
amount removed depends on the type of crown used
– all metallic crowns require the least and all
ceramic require the greatest reduction. If a
large area of the tooth is missing (due to decay
or damage), your dentist will use filling
material to "build up" the tooth to support the
reshaping the tooth, (3) your dentist
will use impression paste or putty to make an
impression of the tooth to receive the crown.
The impression is sent to a dental laboratory
where your crown will be manufactured to exactly
fit. If you have chosen to have porcelain on
your crown, you and your dentist will choose the
best shade and color at this point.
first office visit, your dentist will make a
temporary crown to cover and protect the
prepared tooth while the crown is being made.
Temporary crowns usually are made of acrylic and
are held in place using a temporary cement.
second dental visit, one or two weeks later,
your temporary crown will be removed, and the
permanent crown will be placed. Your dentist
will check its fit and color, and only after
everything appears correct, will it be cemented
permanently in place.
Color selection process
first dental visit, you will have to choose the
color of the future crown. Most patients are
quick to select the whitest shade possible, only
to realize their blunder afterwards.
important that the chosen shade blend with your
remaining teeth. Selecting a shade that is pure
white, but which doesn’t fit your profile, only
helps to identify the crown. The goal for
everyone is to achieve his or her individual
optimum whiteness while still looking natural.
selecting shades, do so under natural light.
Artificial room lighting often changes how a
shade truly appears. Teeth are not
monochromatic, so more than one color is used in
making crowns. If needed, ask whether the dental
laboratory offers custom staining - this helps
to make them appear authentic, but for an added
There is no
one standard system in the dental field to
measure and determine tooth color. The most
often heard about, however, is the Vita shade
guide. This guide divides tooth color into four
basic shade ranges. The guide accommodates for
the fact that the front teeth are typically the
whitest, and the remaining teeth are more
stained and darker as they advance backwards to
the molars. Most dentists will show you a shade
chart (like the above mentioned Vita Shade
Guide) for you to pick from. Other
considerations are your complexion, hair color,
the color of your natural teeth and even your
that teeth whitening does not change the color
of dental crowns. If you plan on bleaching your
teeth in the future, either choose a lighter
shade for your crown, or more sensibly, have
your crown placed after you have bleached your
tooth is never as strong as a healthy natural
tooth – keep this in mind at all times. Avoid
biting on hard objects or using your teeth to
open things (for example, various shelled nuts).
Realistically, you should not be doing these
with your natural teeth, but doing so with a
crowned tooth leaves it susceptible to fracture.
and brushing should be maintained at all times.
A tooth that has received a crown is not
protected by the crown – its actually at a
greater risk of decay.
depending on your dentist, where you live and on
the type of crown selected (for example,
porcelain crowns are typically more expensive
than gold crowns, which are typically more
expensive than porcelain-fused-to-metal crowns).
Generally, crowns can range in cost from $500 to
$900 or more per crown. A portion of the cost of
crowns is generally covered by insurance – check
with your insurance company.
care, dental crowns can last anywhere from 10 to
15 years. The lifespan of a crown depends on the
amount of “wear and tear”, your oral hygiene
habits, and whether you grind or clench your
teeth. Any other bad habits such as holding
objects with your teeth (such as carpenters who
hold nails), or nail biting, can also reduce the
lifespan of your dental
Possible problems that may develop
procedures carry risks that cannot be avoided.
Knowing what to expect can help alleviate
problems when they arise though.
crowns, the most frequent complaint is dental
sensitivity to hot or cold substances. You
can brush your teeth with toothpaste designed
for sensitive teeth (ex, Sensodyne) and see if
it alleviates itself – often it is temporary. If
the pain is not involving temperature
sensitivity, but involving pain on biting, then
the crown is likely too high relative to other
teeth or not placed properly. This should
immediately be brought to the attention of your
use, you might find that your crown has gotten
chipped. Metal crowns rarely chip, while
porcelain crowns are at the highest risk. If the
chip is small, your dentist can use dental
filling material called composite resin to fill
it. If the chip is extensive, the crown will
likely require replacement though.
common complaint is a loose crown. There are
many possible causes such as the cement washing
out, or a poorly constructed crown that never
fully sealed the tooth. A loose crown is a great
concern. It allows bacteria to leak in and
increases the likelihood of decay tremendously.
If your crown feels loose, contact your dentist
some people experience allergic reactions to the
material in the crown. Most often, the allergy
is to nickel found in many nickel-chromium
alloys. This is rare, but will require
replacement of the crown.