DENTAL
PROCEDURES Dental Crowns
The purpose of a dental crown is to encase a needy
tooth with a custom-designed material.
Dentists today have a variety of conservative treatment
options through which to restore teeth.
If possible, these options should be explored and
discussed before selecting the full coverage
crown.
The
Clinical Procedure
During
the crown procedure, your dentist prepares the tooth and makes a molded
impression
of the teeth to send to a dental laboratory. A fitted, temporary crown is
created during this visit
to temporarily protect the tooth while the final restoration is being made in
the dental laboratory.
Once completed, the crown is cemented or adhesively bonded at a later visit.
A
recent technology, CAD/CAM technology (computer-aided design/manufacturing
technology)
has evolved to display a 3-D picture of the teeth. A restoration is then
created through milling
of a ceramic block. If this technology is located in the dental office
(chair-side CAD/CAM), there
will be no need for a temporary crown or return visit for the final
cementation.
Fixed
Partial Dentures, Dental Implants and Crowns
Fixed
partial dentures (aka dental bridges) are an extension of the dental crown
treatment for replacement of missing teeth. Crowns are placed on the teeth
adjacent to the missing tooth or teeth and connected to a missing tooth-like
replica. Although fixed partial dentures may serve
as a functional and esthetic restoration, today’s treatment-of-choice for a
missing tooth or teeth
is with dental implants. A dental implant replaces missing teeth with a
titanium root replica. A crown is then placed on the implant above the gumline. Dental implants are a very predictable treatment
choice, returning support to the bite and preventing the need for the
unnecessary crowning of adjacent teeth.
Crown
Materials: Gold, Ceramic and Porcelain Crowns
The
three predominant choices of restorative materials for the full coverage crowns
are:
. Porcelain-fused-to-metal
. All-ceramic (all-porcelain)
. Gold
The material selected is determined by the clinical
demands at hand; esthetic demands,
strength requirements, material durability and restorative space available.
Porcelain-Fused-to-Metal Crowns
Porcelain-fused-to-metal
crowns provide for a strong, durable, and esthetic treatment option.
One of the key factors for the esthetic and functional success of this type of
crown is ensuring
the preparation of the underlying tooth structure provides adequate space for
the appropriate thickness of the material selected. Additionally, the artistic
skill of the laboratory technologist creating the crown will determine its
esthetic appeal.
One
consideration in the porcelain-fused-to-metal crown is that these crowns may
tend to show
the underlying metal or gold margin at the gum line as gums recede over time.
Some patients opt for this type of crown, but replace the crown at a later date
in order to maintain a higher esthetic benefit. Porcelain-fused-to-metal crowns
with an all porcelain collar can eliminate this vulnerability.
All-Ceramic
Crowns
The
predominant material choice for all-ceramic crowns today is either zirconia, or
aluminous materials. They provide a metal-free esthetic option with a number of
benefits.
By
eliminating the need for the supportive metal core, an esthetic all-ceramic
crown can be created with a reduced thickness of material. This makes them a
more favorable treatment choice in areas with limited space. Additionally, the
elimination of the metal core allows for
light transmission through the porcelain for better optical, life-like
properties and a higher
level of esthetics.
All-ceramic
materials continue to evolve in strength and durability, but caution should
still
be exercised for areas of the mouth requiring heavy function. Continuing
research is exploring
the significant vulnerabilities of the porcelain systems in such areas.
Gold
Crowns
Although
not as popular a treatment choice for esthetic reasons, gold crowns are still
indicated in some instances. For example, patients with strong bites and those
with parafunctional habits (such as grinding or
clenching) might be better served with a gold crown. The traditional restorative
material can provide stronger support to the remaining healthy tooth structure.
Gold crowns offer a level of durability that is appropriate for teeth located
in the back of the mouth (such as the molars), where they will not be highly
visible. Gold crowns tend to offer greater longevity and require less
preparation than porcelain and porcelain-fused-to-metal crowns. When chewing,
gold tends to be less abrasive to the opposing tooth than porcelain. This helps
to prevent wearing of the teeth.
For more information visit our FAQ
page.