What Comes After All on Four? - ProSites, Inc. Web Vers - Copy.pdfimmediate denture prostheses are affixed to the implants. The surgery, records and delivery of the immediate prostheses
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What Comes After
All on Four?
Michael J. Maginnis, D.D.S., M.S.Board Certified Specialist
Removable Prosthodontics
Author’s Note:
The following is one method of completing the surgical and prosthetic treatment known as
“All-on-Four”. The technique involves removal of all of the remaining teeth, placement of
at least four dental implants, some of which are angled to avoid structures such as the
mental nerves and the maxillary sinuses. Records are made of the implant positions for
fabrication of milled bars that will support and retain the final prostheses. Meanwhile,
immediate denture prostheses are affixed to the implants. The surgery, records and
delivery of the immediate prostheses are completed in one day. Approximately four
months later, the milled bar and the final denture prostheses are delivered.
My concern, as a prosthodontist, is that if the implants fail and cannot be replaced, then
the large amount of alveolar bone that was removed during surgery to make room for the
implant abutments and milled bars may eventually create a class of “dental cripples”.
The cases used in this report to illustrate severely atrophied maxillary and mandibular
ridges were caused, for the most part, by periodontal disease or poorly fitted prostheses
and not by implant surgery, per se. They do, however, illustrate the difficulty in treating
patients with gross bone loss, regardless of the reason.
Dr. Michael J. Maginnis, D.D.S., M.S.,
Board-Certified Specialist, Removable Prosthodontics.
All-on-FourDr. Paulo Malo’s:
Dentate Patient
Maxillary Bone Reduction
18 mm
A word of caution: A set of complete dentures needs approximately
18 mm of interarch space. Implant bars and their supporting
abutments need another 5 to 6 mm of space per arch.
drsmanda.com
When constructing traditional immediate
dentures, along with teeth, only a minimal
amount of bone and tissue is removed.
With All-on-Four (or Six) more bone must
be removed to accommodate implant
abutment heads and milled bars.
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If an insufficient amount of
bone is removed, the denture
prosthesis has to be very
thin…and fragile….to
accommodate a milled bar
and implant abutments.
During All-on-Four surgery,
measurements are made to assure
10 –12 mm of space for implant
abutments, milled bar , acrylic base
and denture teeth.
10 – 12 mm
CEJ
To accommodate a milled
implant bar and the supporting
abutments, 5 to 6 mm of bone
must be removed above the
cemento-enamel junction of the
extracted teeth.
CEJ
5 – 6 mm
A clear bone reduction guide is used to
verify that 5 to 6 mm of bone has been
removed above the cemento-enamel
junction of the extracted teeth to
accommodate a milled implant bar and
its supporting implant abutments.
Angled Abutment
Selection and Orientation.
The clear bone reduction guide is
used to verify that the abutments are
within the outline of the planned
prosthesis and that the angled
abutments are parallel to the
planned path of insertion.
White temporary cylinders are seated
on each abutment and secured with an
abutment screw. The cylinders will be
used to transfer the position of the
abutments to a working model.
Following removal of all teeth,
the mandibular ridge is being
prepared for bone reduction to
accommodate a milled implant
bar and its supporting
abutments.
When constructing a bone
reduction guide, reduce height
of lower cast to allow for 12
mm of space between upper
incisor edge and top of
implant.
Following removal of the teeth,
the alveolar ridge is reduced in
height 5 to 6 mm below the
cemento-enamel junction to
accommodate the milled implant
bar and supporting abutments.
The mandibular bone reduction guide is
held in place against the maxillary bone
reduction guide with bilateral ball clasps.
The pre-operative vertical dimension of
occlusion is used to verify that adequate
boney height has been removed to
accommodate the milled implant bar and
supporting abutments.
Implant Placement
Angled Abutment
Placement
Blu-Mousse bite registration
material by Parkell, Inc. is
placed in the alveolar section
of the immediate denture and
is used to record the position
of the temporary cylinders.
The denture prosthesis is
firmly seated in the palatal
vault and held until the
registration material sets.
Position of each
temporary cylinder is
recorded in the set
registration material.
Openings are cut
in the lingual
surface of the
denture prosthesis
to allow for pick -
up of transfer
impression
copings.
Transfer impression
copings are picked up
with self-curing acrylic
resin, two at a
time…anterior first.
Self-curing acrylic resin is injected
into the space around the transfer
impression copings. The denture
prosthesis is held in place until the
resin has cured. The procedure is
then repeated for the two distal
transfer copings.
Openings are cut in the occlusal
surface of the denture prosthesis
to allow for pick-up with self-
curing acrylic resin of the two
distal transfer impression
copings.
With the maxillary denture
secured to the implant
abutment heads, the
mandibular denture can be
secured in a centric occlusion
position with ball clasps. An
accurate transfer of the
position of the mandibular
implant abutment heads can
now be accomplished.
White temporary cylinders
screwed in place on the
mandibular implant abutment
heads.
Blu-Mousse bite registration
material is placed in the
alveolar section of the
immediate denture and is
used to record the position of
the temporary cylinders.
The mandible is held in centric
occlusion position and the pre-
surgical vertical dimension of
occlusion is verified.
Position of each
temporary cylinder is
recorded in the set
registration material.
Attach impression copings to lower denture with
self curing acrylic. As with the maxillary
denture….two at a time, anterior first..
The immediate dentures with
the attached impression copings
are now ready for conversion in
the laboratory to interim
prostheses that will be worn by
the patient during the three to
four month healing period.
In many instances, to
assure better support, five
or six implants are placed,
particularly in the maxilla.
Implant analogs are placed in
the impression copings and
secured with wax prior to
pouring a master cast.
Master cast, with
conversion prosthesis
cleaned of bite
registration material
and prepared for
laboratory reline in
self curing acrylic
resin.
All in one day
All-on-Four
During the three to four month
healing period, milled titanium bars
are fabricated on the master
implant abutment models.
Sufficient space is left between
the bar and the tissue surface
of the model to allow for final
acrylic denture resin to be
wrapped around the bar.
In the final stages of treatment, the
milled bar is tried in to verify fit and a
final prosthesis, in wax, is approved by
the patient.
After the final prosthesis is
processed into acrylic, it is
tried in and relined with
Impregum impression
material and used to create a
final master cast.
Self curing acrylic is
used to replace the
Impregum
impression material
and create a smooth
and polished intaglio
surface that has been
contoured for clean
ability.
Acrylic wears during function and All-on-
Four prostheses are made of acrylic, so it only
stands to reason that at some point, the
prostheses or at least the denture teeth will
need to be replaced…..
…and some patients
ignore the wear for way
too long.
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Replacing the dentures, or at least, the
posterior teeth, can re-establish the proper
vertical dimension of occlusion.
Poor fitting maxillary
denture.
Excessive denture adhesive
required for retention.
Pain in anterior vestibule and
burning sensation in palate.
Heavy anterior occlusion.
Destruction of anterior maxilla.
Inadequate posterior support.
Poor esthetics and speech.
Heavy anterior contact and function
with inadequate posterior support
produces resorption of the anterior
ridge.
Inadequate coverage of the
retromolar pads increases
anterior contact in function.
Destruction of the anterior ridge
from hyper function is a hallmark of
“Kelly’s Syndrome”.
Anterior teeth are set for lip
support, esthetics and speech
production.
Posterior teeth are set on the
occlusal plane which is defined as a
line drawn from the edges of the
maxillary incisors through a point
midway up the retromolar pad
when mounted in CO.
A mandibular treatment partial
denture or trial prosthesis is
constructed with a posterior bite block
set in lingualized occlusion at a vertical
dimension of occlusion that produces
anterior disocclusion in CO and
function.
The trial prostheses are processed into
acrylic, delivered to the patient lined
with soft tissue conditioning material
and worn for a sufficient length of time
to recondition the tissues and produce
functional impressions.
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Depending on the severity of tissue
damage, it may take a month of tissue
conditioning and care by the patient to
bring the tissues back to a comfortable
state.
The prostheses are finished with porcelain teeth in ligualized posterior
occlusion. The anterior teeth are disoccluded in CO and function.
Patient is in her 70’s and has worn dentures for more than 30 years.
For a number of those years she had some implant retention that
was lost and replaced several times. The patient’s health precludes
more surgery so she has opted for a conventional maxillary denture
with o-ring retention on her lone remaining implant.
The upper treatment denture is lined with Hydrocast
tissue conditioning material to eliminate the effects of
long term use of denture adhesives and to produce the
final functional impression.
An index made of the
position of the teeth of the
treatment denture
demonstrates the gross
loss of alveolar ridge
structure.
17 – 20 mm
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Solid bilateral posterior lingualized
occlusion disoccludes the anterior
teeth in function and keeps the
denture seated on the residual ridge.
To insure long term wear, the lingual
cusps are cast in Type IV hard gold.
Thirty-three year old with advanced periodontal bone loss in anterior and
posterior quadrants. Five maxillary and six mandibular teeth were saved and
restored with a combination of fixed and removable prostheses.
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Patient used the combination prostheses for 26 years before the maxillary
abutment teeth failed, necessitating extraction and replacement with a
complete denture.
Lower partial denture with metal occlusals.
Hydroxyapatite augmentation of
tuberosities placed at original
surgery in 1990.
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Atrophic maxillary ridge is the result of
advanced periodontal problems as a young
adult. Patient desires implant placement to
help retain maxillary denture.
Step One: Create clear duplicate of upper denture.
Identify and mark potential
implant sites.
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Surgical stent with gutta percha points imbedded at potential implant
sites.
Step Three: Scan #1
Gutta Percha Markers
Potential position of implants is not within solid bone. Using the
density determining software, new locations ( ) for the implants were
found 6 and 7 mm distal to position of gutta percha markers.
Zimmer® Dental Tapered Screw-Vent
(3.7mm x 11.5mm)
Zimmer® Dental Tapered
Screw-Vent (3.7mm x 10mm)
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Multi-purpose fixture mount / transfer
coping used as implant driver,
impression post and when cut down and
reshaped: a healing head.
Four months later…………..
Locator abutments
Locator male housings
with retentive nylon
insert.
Approximately 10 years previously, patient had multiple implants placed
in the maxilla for a hybrid prosthesis. The implants failed and the patient
presented with a severely atrophic maxillary ridge.
The two implants in the mandible can be used to support a lower partial
denture that will supply occlusal support for the maxillary denture. The
two zygomatic implants remaining from the original surgery will be
exposed and restored with Locator abutment heads to help retain the
maxillary denture.
Soft-lined treatment denture and partial
denture used during healing phase to
reestablish tooth position, vertical
dimension of occlusion, and function.
Ball overdenture heads are used
during the healing phase to help
retain the prostheses.
Locator abutment heads used for
retention of the maxillary denture.
Angulation of abutment heads requires
use of at least one extended range male.
Maxillary and mandibular treatment prostheses.
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Within 6 months, the patient lost the zygomatic
implant on her left side. Four years later, she lost
the one on her right and now uses denture
adhesive to retain her upper denture.
What happens if the patient loses the
implants and there is not enough
residual bone to support new
implants? The patient has become a
“dental cripple”. Molloplast-B, a
heat-cured, silicone soft liner becomes
the best option.
Fifteen years prior to these
pictures, the patient was a
heavy smoker. Over several
years, he had placed and then
lost eight implants and most of
the residual bone.
Now, as a non-smoker he
wished to be retreated. The
residual bone was sufficient to
support two implants with
Locator abutments.
Two Locator abutments support
and retain a complete lower
denture. The central fossae of the
posterior teeth were cast in hard
gold to reduce wear to the
maxillary ceramic restorations.
Prominent lingual cusps of the
maxillary posterior teeth function in
the open, shallow fossae of the
mandibular posterior teeth in
ligualized occlusion. The metal
occlusals are replaceable to maintain
the ideal vertical dimension of
occlusion.
Patient received radiation
treatment to the anterior maxilla
for a cancerous tumor of the left
nares. Several years later, she
had the maxillary left cuspid
(#11) extracted.
The site did not heal and the
bone of the maxilla developed
osteoradionecrosis.
Surgery resulted in the loss of all
maxillary teeth and a large
portion of the bone of the
anterior maxilla. A fistula that
communicated with the left
sinus remained patent.
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Soft-lined treatment prostheses worn
during the healing period.
Only bone remaining for implant placement
is in the tuberosities.
Retention of the maxillary
denture achieved with o-
ring abutments, bilateral
posterior occlusion and no
anterior contact in centric
occlusion or function.
This case was originally
conceived as a fixed hybrid
with distal cantilever
pontics. The pontics caused
movement in the bar and the
case was redone as a implant
borne complete
denture…removable by the
dentist. The two maxillary
implant were never used.
Prosthesis has been in
function for more than 20
years and the patient has
practiced excellent hygiene
as evidenced by the healthy
condition of the gingiva
around the implant
abutments.
The chief complaint is the
worn condition of the
prostheses.
As with all acrylic prostheses, wear
created by function reduces the
effectiveness and appearance of the
prosthesis.
Loss of vertical dimension of occlusion
Occlusal wear
Incisal wear
Maxillary prosthesis with acrylic teeth
replaced with complete denture made
with anterior and posterior porcelain
teeth. Lower acrylic incisors replaced
with IPN resin teeth.
Worn posterior teeth rebuilt
into occlusion with self curing
acrylic resin and then cast
into metal occlusal surfaces.
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True Class III
60 year of history of wearing complete dentures.
Present set is 30 years old.
Soft-lined treatment dentures with mandibular
bite block occlusion are used to assess speech
and appearance, re-establish a comfortable
vertical dimension of occlusion, recondition the
tissues of the ridges and produce functional
impressions.
Functional impressions in the treatment dentures produce master
casts mounted in a Class III occlusal relationship at an increased
vertical dimension of occlusion. The increased VDO allowed for
better positioning of anterior teeth for appearance and speech.
Porcelain posterior denture teeth
set in lingualized occlusion and a
posterior cross bite.
Molloplast-B Heat
Processed Silicone Soft
Liner
Custom contoured
and tinted acrylic.
CEJ
To accommodate a milled implant bar
and the supporting abutments, 5 to 6
mm of bone must be removed above
the cemento-enamel junction of the
extracted teeth.
Only time will tell if this is a good idea
or not.
So, who is Dr. Smanda?
Our Website: Drs. “M” and “A” . Com = drsmanda.com
Our Mobile Site: Mag(innis) App(leton) App = magappapp.com
Our Phone Number: (225) 201-1000
Our QR Code:
magappapp.com
Technology to stay in touchTechnology to stay in touch and educate your patients:
www.drsmanda.com
Drs. Maginnis and Appleton
PROSTHODONTICS:
Dr. Michael J. Maginnis
Dr. Isaac E. Appleton
GENERAL DENTISTRY:
Dr. Glenn E. Appleton
Dr. Thomas C. Kiebach
On the Web: www.drsmanda.com7742 Office Park Blvd.
Baton Rouge, LA 70809
(225) 201-1000
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