There are 4 different types of full
dentures. They are "standard dentures", "immediate dentures", "implant
retained dentures", and "Cu-Sil dentures".
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The standard denture
As you can see from the picture below, the back
of a standard denture ends just behind the hard bone in the roof of
the mouth. They do this because they require as much surface area
as possible to maximize
retention and stability. In the
case of people who gag, the back of the denture can be cut forward
making the denture base look more and more like an arch. However,
the more it is cut back, the less stable and retentive it will be!
 Standard
dentures are made for people who are already missing all their teeth. The
top denture relies on "suction" to retain it, and the hardness of the
underlying tissues for its stability. It generally takes 4 or sometimes
more appointments to make a set of standard dentures.
The first appointment consists of an oral examination,
sometimes X-Rays, and a set of impressions of the upper and lower edentulous
(toothless) ridges (gums). These impressions are poured with plaster to form
accurate models of the shape of the edentulous ridges. Other parameters are
determined such as the shade, size and shape of the teeth that will be
placed on the new dentures.
Upon occasion, the dentist will recommend surgical alteration of the ridges
to remove flabby tissue which will interfere with the stability of the
denture, and sometimes to alter the shape of the underlying bone allowing
for a better fit. In most cases, such surgery is not essential, but can
create the conditions for a MUCH more satisfactory final denture.
Alterations like this are generally money well spent!
In some offices, the first set of impressions are used to make custom
fitting impression trays for a second, more accurate impression. In this
case, there will be one extra appointment in addition to the standard 4
mentioned above.
 The
second appointment consists of deciding how "long" to make the
teeth, determining the plane of the tooth setup (when you smile,
the teeth should be parallel to a line between the pupils of
your eyes), and the correct relationship of the upper and lower
teeth so that when you bite together, the upper and lower teeth
line up correctly. This is done using a lose fitting denture
base and a rim of wax to approximate the position of the teeth. |
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| Both upper and lower wax rims are adjusted to
fit correctly in the patient's mouth so he can speak correctly
without the wax rims "clicking" together, and so that the upper
and lower rims fit together evenly. Ideally, the wax rim should
be visible slightly below the patient's lip when the lip is at
rest. When the patient smiles, the position of the lip is
marked in the wax to help the lab decide which set of teeth are
appropriate for this patient. Once these relationships are
correct, the rims are sent to the lab where they are used to
fabricate the wax-try-in. |
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| The third appointment is called the "wax
try-in". The lab returns the loosely fitting tray from the
second appointment with the actual final plastic teeth lined
up along the outer edge of the wax rim. The wax try-in
looks just like a real denture, except that the base fits
loosely on the gums, and the teeth are embedded in wax
instead of plastic. |
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| This gives us the opportunity to see how
the denture looks and works before we are committed to the
setup. At this point, if something is wrong, it can be
changed. If the teeth look too long, or the patient clicks
when talking, or the midline is wrong, we can send the
denture back to the lab where a technician can melt the wax
and reset the teeth to specification. Here, the patient is
smiling, and the upper lip falls at the top of the teeth,
which is the ideal result. |
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We try the denture in as many times as
necessary until the teeth look and function like we want them to. What
you see is what you get! When everything is perfect, the denture is
sent back to the lab to be processed and finished. The old lose fitting
base and all the wax are discarded, and replaced by a tightly fitting
plastic denture base.
The fourth appointment is the insertion
date when the patient walks out of the office with new dentures. The
plastic tends to shrink while being processed, so some adjustment is
usually necessary before they will get the suction that you might
associate with a new denture. How stable the denture is depends upon the
condition of the ridges.
Immediate dentures
Immediate dentures (sometimes called temporary
dentures) are actually made BEFORE the natural teeth are extracted. The
patient walks into the office with natural teeth, and walks out with false
teeth. The teeth are extracted, and a prefabricated denture is inserted
directly over the bleeding sockets. The patient is still numb from the
extractions, and nothing hurts until he gets home. Generally, most patients do
not complain of much pain after their teeth are extracted and the immediate
denture is inserted. The denture acts like a band aid and reduces pain.
| Does your upper denture make you Gag?
If you have tried everything else, click
here. |
The construction of an immediate denture requires only one or
two preliminary appointments before the insertion date, depending on how many
natural teeth the patient has left. They usually work out reasonably well.
When the patient leaves, he looks much better than when he walked into the
office. The bone that supported the original teeth is still intact, and the gum
tissue is firm. For the first week or so, the denture remains stable and
reasonably retained.
Pre operative
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Post operative
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Post-Op with immediate denture inserted
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In a majority of cases, immediate dentures become permanent
dentures, but there are a number of problems associated with immediate
dentures than may cause the patient to want new dentures made after their gums
have healed, in about a year. These problems account for the alternate name; "temporary dentures":
1. If the patient has more than one or two remaining front
top teeth, it is usually impossible to do a
wax try in. The denture teeth are placed
in about the same position as the natural teeth before extraction. Even
though the denture teeth will be straight, and clean, their position may not
be ideal because there is no way to preview them as we do with a standard
denture. For this reason, not everyone will be happy with the final
appearance of their immediate denture, and may wish to invest in a new one
at the end of about a year when most of the healing has taken place.
2. After the natural teeth are extracted and the immediate
denture is inserted, there is a relatively fast loss of the bone that used
to hold the natural teeth in place. By the end of three weeks, enough bone
has been lost that there is a LOT of space between parts of the denture and
the healing gums. This leads to rapidly increasing looseness and sore spots
which must be removed frequently. In some offices, the dentist will include
a free temporary "soft" reline at about one month after the
extraction/insertion date. This is a simple way to tighten the denture
against the gums, and since the material is a bit rubbery, and frequently
medicated, it makes the denture much more comfortable until enough healing
has taken place to do a permanent "hard" reline (at additional charge).
3. At the end of 4 to 6 months, the immediate denture must
be relined with the same acrylic that the denture base was made from
originally. The longer you wait, (no more than 6 months), the longer you
can expect the denture to remain tight before another reline is needed. The
hard reline is a separate procedure and the cost is NOT generally included
in the original price of the immediate denture. Thus the immediate denture
ends up costing a bit more than the standard denture when the cost of the
reline is taken into account. The hard reline marks the official transition
of the immediate denture into a standard denture.
Cu-Sil dentures
There are a number of
drawbacks associated with full dentures, and
not everyone can successfully wear them. In many instances, false teeth are not
especially useful because of retention or stability problems. For this reason,
even a single healthy tooth left in place can stabilize an otherwise unstable
full denture.
Only recently has it become possible to build a denture
leaving a hole here and there to allow a few remaining teeth to poke through
without ruining the suction which generally holds the denture in the mouth. The
Cu-Sil denture has holes for natural teeth. These holes are surrounded by a
gasket of stable silicone rubber which hugs the natural teeth and allows the
rest of the denture to rest against the gums giving the benefit of suction in
addition to the mechanical stability offered by the immobility of the natural
teeth. These are especially useful in situations in which the remaining teeth
are on the same side or area of the arch as in the example below. Even a single
remaining tooth in the arch can increase the stability of the entire denture
several hundred percent over a completely edentulous (no teeth) arch.
CuSil dentures are not the best solution for people with
numerous, evenly distributed, stable natural teeth. They are advertised mostly
as "transitional" dentures meaning that they are especially recommended when the
remaining teeth are likely to be lost (eventually) for any reason, or in cases
where stable teeth are poorly distributed about the dental arch (as in the case
below). A CuSil denture can stabilize loose teeth and, with care, can extend
their lives. It is also easy to replace lost natural teeth on the CuSil
denture, and the denture can be relined like any other standard denture. In
other words, the CuSil denture can eventually be transformed into a regular full
denture if the patient loses all the natural teeth. I have found them to be
especially useful for upper dentures, but more of a problem for lowers. Lower
CuSil dentures are prone to breakage if the patient is a heavy bruxer (grinder),
especially if the remaining natural teeth are located in the front of the arch.
This is because the holes that allow the penetration of the natural teeth weaken
the architecture of a lower denture.
If there are many stable natural teeth remaining, and
they are distributed on both sides of the arch (unlike the example below) with
some in front and some in back to lend support, a
partial
denture may be as good or even better solution. Partial dentures
have the added advantage of not having to cover the entire roof of the mouth.
Note: If you wish to find a dentist who will make you a
Cu-Sil denture, you may be able to get a referral from one of the 125 dental
laboratories throughout the US and Canada who make them. In order to find a
dental lab who has experience with this product, you may try to contact the
manufacturer of the resins (Present Investment) at the following telephone
number: (954) 426-4666. This manufacturer is located in Deerfield Beach Florida
and is open 9-4 Monday thru Friday.
Cu-Sil denture
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Cu-Sil from side
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Case before removal of 2 teeth
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After extractions and insert
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The images above show a Cu-Sil denture which was used as an immediate
denture. The patient's two front central teeth were extracted, leaving the
natural canine and molar on the patient's left side in position. The image on
the lower right shows the case immediately after the two central teeth were
extracted and the denture inserted. The black arrow points to one of the
patient's two remaining natural teeth. Cases like this tend to result in an
extremely stable and retentive denture.
Overdentures
Overdentures are defined as any removable tooth replacement device that is
inserted over existing teeth or their remnants, replacing these teeth with false
teeth. Prior to modern dentistry, overdentures were very nearly the universal
tooth replacement device since surgical removal of teeth was painful, dangerous,
and frequently impossible without modern anesthetics. In those days, dentures
were made to fit over the rotting stumps of decayed or broken teeth.
Today, non restorable teeth are generally removed prior to the placement of a
removable prosthesis, however, there are still instances where these teeth can
be maintained to the patient's advantage. The most frequently seen overdenture
today involves teeth that have had
root canal therapy. If the roots of these
teeth are still serviceable, the crown may be cut off at gum line and a
removable appliance may be placed over the stumps. Sometimes, the stumps are
themselves covered with filling material or cast metal copings in order to
protect them from decay. The advantage to this is that the roots of these teeth
can maintain the bone that supports them. This bone would otherwise resorb away
leaving less tissue to support the denture. In addition, the root itself can
serve as a "rest", or a vertical support for the denture allowing for more
stability than would otherwise be available.
The addition of a soft denture material such as
CuSil on the denture surface that immediately
overlies the rigid root stumps allows the overdenture to nestle more snugly into
the soft tissue on the roof of the mouth. This allows for more suction to
develop and can frequently improve the retention of an overdenture.
Implant retained dentures
Implants, as mentioned elsewhere, are quite expensive (generally
about $2000 apiece, not counting the tooth replacement that goes on top of
them), but quite effective in retaining an otherwise non retentive denture. A
titanium "screw" is actually placed into a hole drilled into the bone to
approximate the position of teeth. After several months, the titanium has
integrated (attached) into the bone, and the implant is then uncovered and a
post which "pokes" through the gums into the mouth is attached to the implant.
This post may support a porcelain tooth, or it may support an attachment for a
denture. If the patient has NO teeth at all in any given arch (upper or lower),
a full mouth of individual implants attached to porcelain teeth and bridges
could cost about what an expensive automobile costs.
On the other hand, a minimum of 2 implants can maintain a
lower denture which would not otherwise be tolerated by that patient. More than
two implants are needed for upper implant retained dentures. Although the
dentures that fit over implants are considerably more expensive than standard
dentures, they offer the added advantage of allowing upper dentures to be built
in the shape of an arch instead of having to cover the entire palate. This is of
special significance to people who otherwise cannot wear full dentures because
they make them gag.
Implant retained dentures have special
significance for people who cannot wear lower dentures. As an edentulous
(toothless) person ages, and the bone continues to resorb away, lower ridges
frequently disappear entirely. Thus there is no vertical bone underlying the
gums to stabilize a lower denture. These people frequently cannot wear a lower
denture at all. The addition of two implants in the front of the lower jaw can
make it possible to retain a lower denture which would otherwise be impossible
for the patient to tolerate. The image on the left below shows a pair of ball
attachments on implants, and the denture that fits over them is shown in the
image on the right.
Mini
implant retained dentures
 Since
their introduction in the late 1990's, mini implants are beginning to become the
standard of care for retaining lower dentures. Unlike the standard implants
discussed above, there is no three to six month waiting period before mini
implants can be loaded (support the denture). Mini implants can generally be
placed in the lower jaw without cutting an incision in the gums. The only
anesthesia used is an injection directly over the site of each implant. The old
lower denture can then be retrofitted directly over the newly placed implants,
and the patient can use the denture immediately. Furthermore, because the
implants are about the size of a standard wooden toothpick (they are made out of
a titanium alloy), patients who have been told that there is not enough bone to
accommodate standard implants can generally be fitted with minis. The
entire procedure (placing the implants and retrofitting the old denture so that
it is supported by the newly placed minis) takes about one hour. It is
generally painless, and produces very minimal post operative discomfort.
Finally, due to the ease of insertion, this procedure is much less expensive
than standard implants for retaining lower dentures. Click on the image to read
more.
Duplicate dentures
When a new full denture is first made, it is possible to make a
duplicate, or an exact copy of the denture cheaply and quickly. This is a
"quick and dirty" method of obtaining a second denture for emergencies.
Duplicate dentures are made by flowing liquid "agar" around the finished denture
and allowing it to harden. (Agar is a gelatin-like material made from seaweed
which is liquid when hot, but cools to form a flexible rubbery substance similar
to very dense Knox Jell-O. When agar is used in dentistry, it is generally
called "reversible hydrocolloid". It is one of the oldest, but still one of the
most accurate impression materials known.) The original denture is removed
from the agar mold (the agar is cast around the denture in two halves) leaving a
hole in the agar where the denture used to be. The hole is then filled with
liquid plastic; white plastic in the tooth indents and pink to form the base and
flanges. The two halves of the agar form are placed back together and the
liquid plastic is allowed to harden. Duplicate dentures are not especially high
quality since the flowable plastic used to make them tends to be porous and less
resistant to wear, and the delineation between the tooth colored plastic in the
tooth indents and the pink base plastic may not always be exactly at the margins
of the teeth, but these dentures make it possible to keep a spare set of
dentures tucked away just in case the regular denture must be sent out for
repair, or is lost and a new denture must be made. They are frequently
delivered to the patient without adjusting them for sore spots or any other
technical modifications to make them more affordable. Duplicate dentures are
only an adjunctive service and are not intended to take the place of the real
thing. Adjustments cost money, and if the dentist were to spend as much time
and effort on them as he did on the primary service, the duplicate could end up
costing as much as the primary dull denture.
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