MATERIALS USED IN
MAXILLOFACIAL PROSTHESIS
1
 Introduction
 Definition
 History
 Review of literature
 Maxillofacial Impression materials and
advancements
 Maxillofacial Prosthetic Materials
 Auxillary Maxillofacial Materials
 Discussion
 Conclusion
 Reference
2
INTRODUCTION
Facial defects can result from trauma, treatment
of neoplasm’s, or congenital malformations. More
often facial defects referred to the Prosthodontist for
restorations are usually the result of surgical resection
of tumors. Restoration of facial defects is a difficult
challenge for both the surgeon and the Prosthodontist.
Both surgical reconstructions and Prosthodontic
restoration have distinct limitations.
3
The surgeon is limited by the availability of
tissue, the compromise of the local vascular bed
by radiation in tumor patients, the need for
periodic visual inspections of an oncology
defects and the physical condition of the patient.
The Prosthodontist is limited by the inadequate
materials
available
for
facial
restoration,
movable tissue bed, difficulty in retaining large
prosthesis and patient acceptance.
4
Maxillofacial prosthesis :Any prosthesis used to replace part or all
of the stomatognathic and/or craniofacial
structures
5
There are two ways of presenting an
overview of the subspecialty of maxillofacial
prosthesis. One way is by viewing the patient
‘being treated’ and the other is by the ‘type of
prosthesis’ that is prepared for the patient.
6
I ) Patient wise, they are classified as:
1. Surgical - The defect to be restored was created
by a definitive surgical procedure. Ex: Cancer
patients
2. Congenital - The defect is a result of congenital
or developmental anomaly. Ex: cleft lip /palate
and syndromes of head and neck.
3. Traumatic - The defect of the head and neck is a
result of a traumatic experience in automobile
accidents, industrial accidents or suicidal
attempts.
7
II) By type of prosthesis, they can be classified as:
1. Extra oral - Facial restorations. Ex: Nasal
prosthesis, orbital, ocular auricular
2. Intra oral. Ex: Obturator, speech aids,
modified complete or partial dentures and
infant feeding prosthesis.
8
HISTORY:
Even before dentistry attained its status as a
profession, some surgeons had recognized the
limitations inherent in grafting tissue for repair of
certain maxillofacial deficiencies and had argued
the use of prosthesis as an alternate method.
Artificial eye and foot found in Egyptian
mummy, the use of artificial eye and noses by
the Indians and the Chinese lead us to think that
they applied their skill to prosthetic restoration
also.
9
BEFORE 1600 AD
Ambroise
pare,
(1510-1590)
the
famous
French surgeon appears to be the first medical
writer
on
this
subject.
He
recommended
a
prosthetic nose, which could be made of gold,
silver, paper and linen cloth glued together. He also
described the fabrication of an auricular prosthesis.
10
1600-1800
Maxillofacial prosthetics owes much to Pierre
fauchard
(1678-1761).
monumental
contribution
Fauchard
to
made
prosthetic
a
facial
reconstruction, he made a silver mask to replace
the lost portion of the mandible for a french
soldier. This prosthesis was constructed under the
direction of a military surgeon, in collaboration
with a silversmith for french artillery. The victim
later came to be known as the “GUNNER WITH
THE SILVER MASK”.
11
1800-1900
William Morton (1819-1868) also did some
pioneer work is Maxillofacial prosthetics. He
constructed a nose out of porcelain for a Boston
lady who had lost her own from a malignant
disease. Dr. Morton attached the nose to her
spectacles.
Frenchman Claude martin published a book
in 1819 and described using a ceramic material to
fabricate a nasal prosthesis.
12
1900-1940
Upham (1901), a Boston dentist described
the use of vulcanite rubber for the fabrication of
nasal and auricular prosthesis.
In time, however some workers showed
dissatisfaction with vulcanite due to their poor
color stability, translucency and rigidity.
13
In Germany (1913), the gelatin - Glycerin
compounds attracted much attention due to their
ease to manipulate, pliability, translucency and
adaptability of intrinsic coloring to match the
skin. But this material lasted only a few days or a
week.
Bulbulian
Clarke
then
introduced
prevulcanized latex which was used with water
soluable dyes.
14
1940-1960
Acrylic resin polymers were introduced and
replaced older vulcanite rubber. Its translucency,
colorability
attractive
and
to
ease
most
of
processing
clinicians.
was
Transparent
photographic paints, acrylic resin polymer stains,
water color, oil colors were also used.
15
1960- 1970
Silicone elastomers were introduced
Barnhard was the first to use silicone and
coloring the facial prosthesis by combining a
silicone rubber base material with acrylic resin
polymer
stains.
Tashma
used
dry
earth
pigments.. Schaaf described the use of artist oil
paint. Fine described the use of colored nylon
flocking
16
1970-1990
Different types of elastomers came into market.
Lontz – polysiloxane elastomers
Gonzalez - polyurethane elastomers
Lewis - Siphenylenes
Turner - isophorone polyurethane
Drane and udagama - Silastic medical adhesive
silicone type A
17
1990- to present
Advances in polymer chemistry has renewed
interest in developing new materials
Gentleman-polyphosphazenes
Silicone block polymers
18
REVIEW OF LITERATURE
19
Aziz T, Waters M, Jagger R J. Biomed Mater
Res B Appl Biomater. 2003; 65 :252. Development
of a new poly(dimethylsiloxane) maxillofacial
prosthetic material.
A new poly(dimethylsiloxane) material with
improved mechanical properties was compared to
commercially available materials. The formulations
developed were based on condensation chemistry
containing
a
poly(dimethylsiloxane),
hydroxy-end-blocked
hydrophobic
silica
filler,
silane cross-linking agents, and a tin catalyst.
20
A formulation was developed with a base
polymer mix of 80%:20% high- to low-molecular-
weight polymers into which 20% w/w filler was
added. This formulation had a tear strength
better
than
compared
to
the
commercial
materials
21
Bellamy KE, Waters MG. Biomed Mater Eng.
2005;15:21-7. Designing a prosthesis to simulate
the elastic properties of skin.
They discussed a three-layered maxillofacial
prosthesis consisting of a silicone rubber base
layer, an inner gel layer and an outer polymeric
coating (to simulate the elastic properties of skin).
Gels were made by the addition of both low and
high molecular weight unreactive silicone fluids.
The results of the study shows that the gel
produced, closely simulates the elastic properties
of skin when bonded to a base silicone rubber
layer. Further clinical trials are needed.
22
FOR MODELING OF AN EXTRA-ORAL IMPRESSION
• Conventional method (using impression material)
• CT and MRI
• 3-D optical scanner (light source)
23
IMPRESSION MATERIALS
PLASTER OF PARIS
Highly accurate in reproducing details
But it is lengthy and time consuming technique.
Used mainly to reinforce alginate impression.
24
RUBBER BASE IMPRESSION MATERIAL
Provides good details
Mainly for intra oral use
Expensive
25
ALGINATE
Most widely used
Excellent reproduction of details
Overall cost is reasonable
26
Disadvantage of conventional impression
 Discomfort to the patient.
 Deformation of the soft tissue because of the
weight caused by the impression material.
 Master cast for the reconstruction of the orbital
defects usually show the remaining eye closed,
so the technician must rely on other data (e.g.photographs) for the design of the orbital
structures.
 Testing ability of the clinician.
27
CT AND MRI
The difficulties encountered while using
impression material was overcome by the use of
CT AND MRI
CT AND MRI scan the defect area and a CAD
model of the defective area and the prosthesis
pattern is designed. The prosthesis pattern is
obtained by a procedure known as rapid
prototyping.
28
Disadvantage
Radiation is more with CT
Length of the time that the patient is required to
be exposed and remain motionless- during MRI
scanning
29
OPTICAL THREE DIMENSIONAL SCANNER
Newer device used to scan the facial defect
and reproduce a model
It is a mobile multi-view 3D measuring system
based on self calibration projection technology.
It facilitate the fully automatic recording of the
body parts from various direction in one
measuring process
30
31
A transmission grating with parallel lines
inside the projector produced a fringe pattern on
the face
These pattern are recorded by camera and
transmitted to the PC
The generated CAD model is converted into
a physical model by means of a rapid prototyping
procedure.
32
33
ADVANTAGE
 The body parts are exposed to light and
recorded optically.
 Time taken for measurement-10 to 20 seconds.
 Accuracy- 100µm.
34
RAPID PROTOTYPING
Rapid prototyping, operate on the principle of
depositing materials in layers or slices to build
up a model rather than forming a model from a
solid block. The use of a CT OR MRI allows
parts of the body to be serially recorded slice by
slice. Similarly, an object can be reproduced
slice by slice using the three dimensional
computed data in conjunction with a rapid
prototyping machine
35
STEREOLITHIOGRAPHY
It is a method of rapid prototyping that uses
data obtained from CT OR MRI scan stored in 3dimensional form
36
Works based on the principle of
curing liquid photomer into specific
shape
STEREOLITHIOGRAPHY
A vat which can be lowered and
raised filled with photocurable
liquid acrylate polymer
Laser generating U-V beam
focused in x-y directions
is
The beam cures the portion of photo
polymer and produces a solid body
This process is repeated till the level
b is reached as shown in the figure
Now the plat form is lowered by
distance ab
Then another portion of the cylinder
is shaped till the portion is reached
37
MATERIALS USED IN
MAXILLOFACIAL
PROSTHESIS
38
Generally an ideal material should have the following
characteristics –
 Non-toxic.
 Odorless.
 High tear strength.
 High edge strength.
 Ease of processing.
 Dimensionally stable during and after processing.
 Ease of intrinsic and extrinsic coloring with
commercially available colorants.
 Ease of repair and refabrication if needed.
39
 Chemically inert after processing.
 Non-porous after processing.
 Long shelf life.
 Long working time.
 No water sorption.
 Translucent.
 Softness compatible to tissue.
 Usable life of two years or more.
40
A number of materials are available and have
been used for facial prosthesis. The materials
currently in use are:
I. ACRYLIC RESINS
The material is readily available and most
dentists are familiar with its physical to chemical
properties and processing techniques. These
materials can be successfully employed in specific
types of facial defects particularly those in which
little movement occurs in the tissue bed during
function.
41
Heat polymerizing MMA is preferred over the
autopolymerizing form because of the presence
of free toxic tertiary amines in the later. Facial
prosthesis
made
serviceable
up
of
to
this
2
material
years
but
remains
required
occasional repainting of the surface. With age,
however the prosthesis becomes shiny and
crazing is noted.
42
Advantages:
a. Both intrinsic and extrinsic coloration can be
performed.
b. Has good edge strength
c. Alterations can be easily affected.
d. Compatible with most adhesive systems
e. Color stability is good in heat polymerized MMA.
f. Can be easily relined with tissue conditioner of
denture liner.
43
Disadvantages:
a) Rigidity,
therefore
its
usefulness
is
compromised in highly movable tissue beds
leading discomfort and expose of margins.
b) High thermal conductivity.
c) Duplication
is
not
possible
because
of
destruction of the mould during removal from
flasks.
44
II. ACRYLIC CO-POLYMERS
Conta and Hildested did extensive study on this
material but did not receive wide acceptance, despite
being soft and elastic because of a number of
objectionable properties like poor edge strength, poor
durability, degradation when exposed to sunlight.
Disadvantages:
 Processing and Coloration are difficult.
 The completed restoration often tacky, predisposing
to dust collection and staining
45
III. VINYL POLYMERS AND COPOLYMERS
a. Commonly marketed as (Realistic and Mediplast,
prototype III)
Is a flexible plastic material basically plasticized
polyvinyl Chlorides (PVC) or copolymer of
Polyvinyl acetate.
The primary deficiency arises from the leaching of the
plasticizer and resulting hardening of the
prosthesis.
The lifespan as reported by Castleberry (1973) has
been extended to 9-11 months.
46
Advantages:
 Adaptable
to
both
extrinsic
and
intrinsic
coloration.
 Flexible.
Disadvantages:
 Migration of plasticizer leading to discoloration
and hardening.
 Easily get stained when exposed to ultra-violet
light, peroxide and ozone.
47
 Poor edge strength.
 Tend to absorb sebaceous secretions, cosmetics
and solvents.
 They soil easily because of surface tackiness.
 Metal
moulds
are
required,
as
curing
is
accomplished at high temperatures
48
IV. POLYURETHANE ELASTOMERS:
(Epithane - 3)
These elastomers are called so because they
contain urethane linkages. They arise from two
major reactants. In the presence of a catalyst, a
polymer terminating with an isocynate is combined
with one terminating with a hydroxyl group. Varying
the amount of isocynate will change the physical
properties of the final product.
49
They are quite elastic and flexible especially
well suited to defects with movable tissue bed.
Isocynate are moisture sensitive and when
water contamination occurs, gas bubbles causes
defects and poor curing of the material. The
reaction
must
be
carried
out
in
a
dry
atmosphere. The processing temperature is
100o C.
50
Advantages:
 Good edge strength.
 Can
be
colored
both
intrinsically
and
extrinsically.
 Superior cosmetic results when compared to
other materials currently available.
 Stone molds are acceptable but care should be
taken
to
thoroughly
dehydrate
before
processing.
51
Disadvantages:
 Difficult to process consistency.
 Isocyanides, as these compounds are toxic and
moisture sensitive due to which gas bubbles can
accumulate and cause defects and poor curing.
 Extrinsic coloration tends to wear off rapidly.
 Clinically, the life range from minimum 3 months
to maximum 6 months.
 Poor compatibility with existing adhesive
systems.
52
V. SILICONE ELASTOMER
The silicones are probably the most widely used
materials for facial restoration. Silicones are a
combination
of
organic
and
inorganic
compounds. The first step in their production is
the reduction of silica to elemental silicon. Then
by various reactions the silicone is combined
with methyl chloride to form dimethyl
dichlorosixane, which when it reacts with water
53
forms a polymer.
These polymers are translucent, watery
white fluids whose viscosity is determined by
length of the polymer chain. Polydimethyl
Siloxane commonly referred to as silicone is
made from these silicone fluid polymers. Most
rubbery forms are compounded with fillers that
provide additional strength. Additives are used to
provide color. Antioxidants and vulcanizing
agents are used to transform the raw mass from
or plastic to a rubbery -resin during processing.
54
The long-chained polymer which is crosslinked create a network that can be separated
only with difficulty. This network makes the
silicones especially resistant to degradation from
UV light exposure.
55
The process of cross-linking the polymers is
referred to as vulcanization. Vulcanization
occurs both with and without heat and depends
on the catalytic or cross-linking agents utilized.
Depending on the method of vulcanization, two
forms are available:
1. Those that require heat - Heat vulcanized
(HTV)
2. Those that vulcanize at room temperatureRoom temperature vulcanized (RTV)
56
Silicones are classified into four groups according
to their application
1. Implant grade- material that can be implanted
interstitially.
2. Medical grade- for
maxillofacial silicones.
external
use
eg-
3. Clean grade.
4. Industrial grade- both are used for industrial
application.
57
Heat Vulcanized Silicones (HTV):
Supplied as one component or two component putty.
The
catalyst
or
vulcanizing
agent
is
dichlorobenzoyl peroxide or platinum salt,
depending on the type of polymerization.
Various amounts of filler are added to these
polymers depending on the degree of hardness,
strength and elongation desired. The more filler,
the harder and less resilient the compounded
rubber will be.
58
The filler is very pure finely divided silica
with a particle size of about 30.
Co-Polymers like methyl vinyl or methyl
phenyl siloxy radical are added for softness
and tear strength.
Advantages:
a. Exhibit excellent thermal stability.
b. Color stable.
c. Biologically inert.
59
Disadvantages:
a. Do not posses sufficient elasticity to function in
movable tissue bed.
b. Poor edge strength.
c. Are opaque and have lifeless appearance.
60
Room temperature silicones (RTV)
It is a viscous silicone polymer that includes
a filler and catalyst, which also acts as crosslinking agent.
Stannous octoate is the common catalyst
used.
Filler, like diatomaceous earth are added to
increase strength.
The properties of RTV are similar to the HTV
types, except for the ease of processing of
RTV’s.
61
Advantages:
 Same as HIV Silicones.
 Easy to process and stone molds can be used.
Disadvantages:
 Same as HTV silicones except for its ease in
processing.
62
FOAMING SILICONES
It is a form of RTV silicone. They reduce the
weight of prosthesis because of formation of
bubbles within the mass.
The basic silicone has an additive so that a
gas is released, when catalyst stannous octoate is
introduced. The gas forms bubbles within the
vulcanizing silicone. After the silicone is
processed, the gas is eventually released leaving
a spongy material. And the formation of bubbles
within the mass can cause the volume to increase
by as much as seven times.
63
DISADVANTAGE
 Has reduced strength.
 Susceptible to tearing.
 Because of these problems its use is limited.
64
VI. SIPHENYLENES:
(polytetramethylsiphenylenesiloxanedimethylsiloxane)
These belong to silicone family that contain
methyl and phenyl group.
It is a pourable, viscous, room temperature
vulcanizing liquid.
Three component kit
Consist of a base resin
crosslinking agent- tetrapropoxysilane
catalyist- organotin
Siphenylenes elastomers feels like skin.
65
 Are biocompatible, resistance to degradation on
exposure to ultraviolet light and heat.
 Have good edge strength and colorability.
Advantage:
 Edge strength and colorability is superior to
silicones.
Disadvantages:
 Not enough clinical trials have been done due to
limited research on this material.
 High cost.
66
SILICONE BLOCK POLYMERS
 Developed to improve some of the weakness of
silicone elastomers.
 Incorporates
poly methyl methacrlyate into
silicone block.
 Has been found to be more tear resistant than
conventional cross linked silicone polymers.
67
POLYPHOSPHAZENES
It has been developed for resilient denture
liner.
Properties of this material is been modified to
satisfy the requirements for fabrication of
maxillofacial material.
68
AUXILLARY MAXILLOFACIAL MATERIALS:
Primers
These are used to promote bonding of
silicone and other maxillofacial material.
69
FACIAL PROSTHETIC
ADHESIVES
Facial
prosthesis
may be retained by
mechanical means or
by
the
use
of
adhesives.
70
No one adhesive will behave in the same
way to different patient. This mainly due to
adhesive reacting to various skin types, ie oily,
dry, flaky etc and each skin type will exhibit
varying degree of retention.
71
They can be classified as
 Pastes. (PSA 1)
 Liquids [paintable (pros-Aide, DC-355) or
spray-on (DC MED)].
 Double sided tapes( 3M biface tape).
72
TISSUE CONDITIONING
Used to prevents the skin damage when
removing the adhesives. It forms a protective
barrier.
Comfeel protective film
It contains ethoxyethyl acid co-polymer ethyl
acetate
When applied it forms a chemical film that is
compatible with adhesives, so increasing the
adhesion qualities of the prosthesis to the skin
73
Skin prep protective dressing (Smith & Nephew
Inc) are used to enhance the prosthesis
adhesion and to protect the skin from trauma.
Composition
 Isopropyl alcohol.
 Butyl esters of poly vinyl methacrylate/ methyl
methacrylate copolymer.
 Acteyl tributyl citrate
74
Technique of application of adhesives
Apply the adhesive to 6 to 7mm of the
periphery of the fitting surface
To prevent the break down of the fine thin
edges,
leave
the
last
4mm
without
any
adhesives, instead Vaseline may be applied to
them to make the margin disappear
75
ADHESIVE REMOVER
The biggest problem
as far as the patient is
concerned is the
removal of the remaining
residual adhesive from
the skin.
76
 Plaster remover.
 Zoff prosthetic cleanser. Trichloroethane
 Thackeray cleanser.
 Acetone.
 Krylon medican spirit gum remover
 Uni-solve adhesive remover
Isoparaffin.
Isopropyl alcohol.
Dipropylene glycol methyl ether.
Aloe extract.
77
Technique of removal
To remove the prosthesis
Lift the edge using a cotton bud or gauze
soaked in the remover, slowly working around
and
under
the
fitting
surface,
lifting
the
prosthesis away from the skin as you go.
78
To clean the adhesive from the skin
Soak a piece of gauze in the remover and by
gently rubbing and turning the gauze constantly.
Finish off by washing with soap and water.
79
To clean the prosthesis
Initially rub the thumb over the fitting surface,
causing the adhesive to “ball” for easy removal.
Finally use the gauze soaked in remover to
clean the fitting surface.
If still traces of adhesive remain soak the
prosthesis in the solvent for one or two minutes
and then use a gauze swab.
80
DISCUSSION
Since the sixteenth century acquired surgical
defects
have
replacements
been
restored
constructed
from
by
a
prosthetic
variety
of
materials and techniques. The cosmetic and
functional disabilities following radical surgery for
oral and paraoral cancer are significant and
disabling.
Definitive
reconstruction
should
be
performed wherever possible as part of the
ablative procedure.
81
When definitive reconstruction is coordinated
and
combined
with
maxillofacial
prosthetic
rehabilitation, head and neck defects can be
restored to near-normal function and appearance
in many cases. The traditional concept of a onetime
prosthesis
that
supplies
the
patient's
requirements through the course of life is no
longer realistic or valid.
82
Identification of the variable factors that
influence the serviceability of prostheses for the
treatment of jaw defects is important and useful
information for the patient, the family of the
patient, the rehabilitative team, and third-party
payers.
83
CONCLUSION
Jaw defects affect many vital functions (that
is, respiration, mastication, deglutition, speech,
and aesthetics). Ideally, any anatomic defect
should be surgically reconstructed. However,
when surgical reconstruction is contraindicated,
prosthetic reconstruction must be employed to
restore anatomy, function, and aesthetics.
84
Effective communication between the surgeon
and the maxillofacial Prosthodontist is essential
for developing a realistic treatment plan or
rehabilitation of patients undergoing resection.
Preoperative
consultations
allow
the
prosthodontist to make recommendations to the
surgeon to achieve better prosthetic results.
85
The team concept, in which the head and
neck surgeon, speech pathologist, radiation
oncologist,
maxillofacial
Prosthodontist,
and
other members of the health profession function
together in planning the rehabilitation and
primary modes of therapy, ensures the patient's
early and successful rehabilitation
86
REFERENCE
 Maxillo Facial Rehabilitation – Prosthodontic and
surgical consideration.
JOHN BEUMER.
 Clinical Maxillofacial Prosthetics THOMAS D. TAYLOR.
 Prosthetic rehabilitationKEITH F THOMAS.
87
88