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TOOTH
REPAIR
Simple (Direct) Fillings
Direct fillings are created in the tooth,
completed in one appointment, and are used to fix teeth only mildly
or moderately affected by a problem. First, the tooth is prepared
to remove the problem, like decay or staining. Next, if the filling
being used is a white type, the prepared surfaces of the tooth are
conditioned to bond to the filling. Last, the filling material is
placed in the tooth, properly shaped, and allowed or encouraged
to harden, thus replacing any lost tooth structure. Two primary
types of direct filling materials are used: metal amalgam (silver)
fillings, and resin (white) fillings.
White (Resin)
The most obvious advantage of white fillings is their beauty--a
well-done resin filling can be indistinguishable from the natural
tooth. Other advantages of resin fillings include the ability to
change the appearance of teeth, strengthen teeth, and more conservatively
treat teeth.
Resin fillings are bonded to tooth structure--this
means that they actually integrate with the tooth, thereby sealing
the gap between tooth and filling and adding their strength to the
tooth. This allows more varied uses of resin beyond just regular
fillings--like placing thin layers over front teeth to change their
color, shape or general appearance; or repairing small chips or
fractures in teeth; or even being placed in the grooves of teeth
to prevent decay from ever occurring. Bonding is an extremely beneficial
advance in the success of modern dentistry.
White fillings are made of reinforced resin materials.
They begin as soft, sculptable paste or viscous fluid that eventually
becomes hard--some are self-hardening, but most harden when exposed
to light of certain wavelengths. As a paste or fluid, the resin
material is placed in a prepared tooth and conforms to the shape
of the interior of the tooth. The exterior surfaces are then sculpted
to either reconstruct the original appearance of the tooth or to
create an entirely new appearance. Light-hardened resins have the
advantage of remaining in their paste/fluid form until the dentist
decides it is time for hardening and exposes the paste to a special
light--this gives extra time to make the fillings beautiful.
Amalgam (Silver)
Amalgam is an alloy of metals that when first mixed becomes a dry
paste but quickly hardens into a solid mass. It has been used in
dentistry for over 150 years because of its success, low cost, and
ease of use. Yet significant debate has raged about its use because
amalgam contains mercury, a substance that in its elemental form
can be a lethal poison. However, mercury in fillings is not in its
elemental form--it is oxidized---and there is no significant evidence
after years of research to show that the small amounts of mercury
in fillings cause any form of disease or pathology. In reality,
the biggest disadvantages of amalgam fillings are that they look
very unnatural, varying from shiny silver to crusty black in appearance,
and that they offer little support to the tooth. Because of these
disadvantages, their use is diminishing throughout the world as
newer, stronger, longer-lasting white filling materials are introduced.
In our office, we have chosen to offer only white fillings because
of their many advantages.
Complex (Indirect) Fillings
Indirect fillings are created outside the mouth after the
tooth is prepared and are then cemented in place or bonded to the
tooth. Usually two appointments are required--one to prepare the
tooth and make a mold of it, and a second to fill the tooth with
the custom-made indirect filling. Complex fillings are of two major
types: inlays and onlays. They are used to restore teeth with small
or large problems, from minor decay to large fractures.
Indirect fillings can be created out of metal,
reinforced resin, or porcelain. Metal provides great strength but
lacks beauty. Resin & porcelain provide beauty but do not have
metal's strength. However, when placed properly resin and porcelain
restorations have proven to be very durable and long-lasting, similar
to metal. Therefore, most indirect fillings done today are made
of resin or porcelain.
Inlays
Inlays do not cover the cusps (peaks)
of a tooth and are generally small. They are used to restore teeth
with mild to moderate problems, just like direct fillings. The only
perceived advantage of inlays over direct fillings is strength,
but research is showing that direct fillings are comparable to inlays
in success rate. Therefore, we prescribe inlays in only a few cases
because of their much greater cost when compared to direct resin
fillings.
Onlays
Onlays cover one or more cusps (peaks) of
a tooth to protect the tooth from fracture, much like a crown does,
and therefore can be used to restore teeth with even major structural
problems. While a crown surrounds the tooth and covers all of the
outside tooth surfaces, and onlay rests inside the tooth and only
covers the top chewing surfaces. In this way the borders where the
tooth and onlay meet are kept mostly away from the gumline, where
they can cause gum irritation. Crown margins generally lie at or
very near the gumline, so crowns have a much higher incidence of
gum irritation than onlays. In certain cases, though, onlays may
not be as durable as crowns and should not be the treatment of choice.
Crowns
Crowns, also known as caps, are basically
"helmets" for a tooth, covering nearly the entire visible
surface of the tooth. They come in many forms and have many uses.
Crowns are generally used to protect and restore weak, worn or damaged
teeth but can also be used to alter a tooth's appearance, position,
shape, contour, and/or color. They can also support and retain other
prosthetic devices such as a partial denture, or they can adjust
a person's bite for prevention or treatment of damage to the TemporoMandibular
Joint (TMJ).
The three most common types of crowns are discussed below.
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porcelain vs. metal
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porcelain vs. metal
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All-Porcelain
With advances in the strength and durability
of ceramics, crowns can now be made entirely out of porcelain. The
primary advantage is obviously in beauty--all-porcelain crowns can
be made to look just like your natural teeth. Another advantage
is that because they contain no metal, there is no occurrence of
allergies.
The most common use of all-porcelain crowns is on front teeth where
appearance is exceptionally important. Because they contain no metal,
light passes through them similar to natural teeth, so they have
a very natural appearance. While all-porcelain crowns still may
not fully match up to metal crowns in strength and durability, clinical
use of them over the last several decades has proven that when placed
judiciously, even on the back chewing teeth, they can be very natural-looking,
long-lasting replacements for all-metal or porcelain-and-metal crowns.
All-Metal
Some crowns are made entirely out of metal,
such as gold or silver alloy. Advantages of metal crowns include
their strength and durability, as well as their excellent fit. Unfortunately,
they are not very natural or beautiful, and some alloys contain
metals, such as nickel or zinc, that have a relatively high incidence
of allergy and can therefore cause irritation to oral tissues.
While all-metal crowns are still used in dentistry, they are much
less common now than in the past. They are used primarily in situations
where high chewing stresses are expected and may cause premature
failure of crowns made with porcelain.
Porcelain-Fused-to-Metal (PFM)
The most commonly used type of crown is one
including both porcelain and metal. Basically, a thin layer of metal
is used as a base or support and porcelain is then baked onto it--the
idea is to combine the strength of metal with the beauty of porcelain.
Often a thin line of metal is visible along the edge of the porcelain,
although the metal can be completely hidden underneath the porcelain.
While PFM crowns are definitely more beautiful
than metal crowns, rarely do they match up to all-porcelain crowns
in beauty. And while PFM crowns are more fracture-resistant than
all-porcelain crowns, they can still fracture unlike all-metal crowns.
Thus, while PFM crowns do incorporate good aspects from both metal
and porcelain, they are not the perfect solution in all cases. Also,
for individuals who have metal allergy, PFM crowns may cause a reaction.
PFM crowns are most commonly used on the back
chewing teeth. Here their strength is an advantage, yet the less
natural appearance is not as noticeable because they are not as
visible when one smiles. PFM crowns can and are used on front teeth
in cases where strength is required, and if created properly, they
can be very beautiful.
Root Canal
Prior to recent advances in dentistry, damage to the core of a tooth
usually meant its quick removal. The modern solution is a root canal,
known in the dental community as endodontic treatment. A root canal
procedure cleans, disinfects, and refills the interior of the tooth,
thereby preventing serious pain and further damage to the tooth.
Modern technology has made root canals faster, simpler, more successful,
and--most importantly--more comfortable for patients.
To perform a root canal, the affected tooth is
first anesthetized (numbed). All damaged or decayed tooth structure
is then removed, and a hole is made in the top of the tooth down
into the pulp--the internal tooth tissue containing the nerves and
blood vessels of the tooth. The canals that extend into the roots
of the tooth are then located, and tiny metal instruments called
files are used to remove the remaining pulp from and enlarge the
canals. The canals are then thoroughly cleaned and disinfected with
sterilizing fluids. Once enlarged, cleaned, and sterilized, the
canals are filled with a rubberized inert material that helps prevent
future infection, and are then sealed as the tooth is filled with
a bonded core material. If necessary, metal posts may be inserted
into one or more canals of a severely damaged tooth prior to the
core placement to provide long-term structural support. In many
cases, at the same visit the tooth can even be prepared for its
final restoration--which is usually a crown--thus reducing the number
of visits required of the patient.
After completion of a root canal, most patients
experience little or no discomfort--in fact, they are often more
comfortable as the pain of the infected tooth has been alleviated.
A root canal saves the tooth, and upon full restoration the tooth
becomes nearly indistinguishable from other teeth and can be used
just as if it were a natural tooth.
TOOTH
REPLACEMENT
Bridges
A bridge is a device used to fill
the space where a tooth has fallen out or been removed. A typical
bridge consists of a pontic (a filler tooth) that is attached to
two surrounding teeth. Once complete, this bridge structure is bonded
into the mouth. Without the use of a bridge, spaces in the mouth
from missing teeth can cause multiple teeth to shift, lead to occlusion
(biting) and/or jaw problems, and spur periodontal disease. Bridges
safeguard the integrity of existing teeth and help maintain a healthy,
vibrant smile.
Implants
If you are missing teeth, dental implants
can improve your health and appearance. Whether you need to replace
a single tooth or all of your teeth, implants provide greater support
and last longer than either bridges or dentures. Implants can make
chewing and speaking easier. By improving the appearance of your
smile and maintaining the natural contours of your face, they may
also boost your self-confidence. Dental implants look and feel more
like natural teeth than dentures do, and if you can't keep your
originals, implants are the next best thing.
Complete Dentures
Complete dentures are used when few
of the original teeth remain. The dentist begins by removing any
remaining teeth so the dentures can be fitted. He or she then makes
a mold of the gums and sends it to a dental lab where customized
dentures are constructed. Patients are typically fitted with temporary
dentures until the permanent set of dentures have returned from
the laboratory.
Over Dentures
Over dentures are prepared in much
the same way as a complete set and are utilized when only a few
teeth are missing. If the roots of a patient's remaining teeth (the
tissue and gums) are strong, the dentist may suggest over dentures.
Over dentures fit on top of the remainder of teeth in the mouth.
With over dentures, the remaining teeth are resculpted and covered
with metal caps to help prevent future decay. The advantage of over
dentures is that they do not have to be relined as frequently as
a complete set of dentures because the jawbone and gums recede less.
In addition, over dentures create less occlusion (bite) problems
than complete dentures.
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