In evolving a successful prosthetic facial
replacement ,3 factors are necessary:
1. Creative ability
2. Technical knowledge, &
3. Materials which will allow the prosthodontist
to fully exploit these talents.
Objectives Of Maxillo-facial
Restoration of esthetics or cosmetic appearance of
Restoration of function
Protection of tissues
Therapeutic or healing effect
Ideal Requisites Of Maxillo-facial
3. Color and translucency
4. Chemical and environmental stability
5. Thermal conductivity
6. Ease of Processing
7. Strength –
8. Ease of duplication
1.Low Viscosity at
2. Intrinsic and
4. Sufficient working
5. Low curing
Criteria For Maxillo-facial Materials
• Non allergic
• Chemical and environmental
• Moderate cost
• Easy adherence to living
The impression serve 2 purposes:
1. Allows the dentist to accomplish the
preliminary modeling without the patient
present, which saves chairside time,
eliminates unnecessary discomfort to the
2. Patient education and teaching aids are also
served with the resulting model.
Room Temperature Vulcanizing
1. Fine detail obtainable
2. Inherent strength.
3. Easy to obtain.
1. Needs backing.
2. Difficulty in adjusting setting time.
3. Retaining walls needed for confinement of
4. High cost.
• sufficient body and strength
• Should be possible to accept texture into this
material which will be imparted to the
• The closer the color of the material to skin
tone, less visual distortion
1. Modeling clay (sculptor’s clay)
water based clay , when allowed to dry, becomes
a hard stone like substance.
feathered on the
gray in color, and
the color differential
Must be kept moist
at all times
• Readily available
• Can be shaped or molded
in its plastic state
• Easily and quickly prepared
• Lacks elasticity
• Adding material to build
contour is difficult
• Tendency to flake on the
• Cannot be used in
prepared modeling clay with oil base
Takes texture well
Always ready for use
Color does not match skin
seep into stone model and
affect the finished product
keeps a feather
to skin tone
Model must be
Properties similar standard dental waxes,
except for 2 characteristics:
1. Due to low melting point, body heat allow
it to become malleable & modeled quite
readily with the fingers and hands
2. The color is good in relation to skin tissue.
Fabrication phase materials
Extraoral materials – acrylic resin
vinyl chloride polymers
Intraoral materials -- silicones
poly (methyl methacrylate)
At present silicones and polyurethane materials
are considered most desirable - strength, even
though both are somewhat difficult to color.
J of Biomedical material research 2004:8(4);349-363
Extra oral materials
1. Poly-methyl methacrylate
2. Polyvinyl polymers and copolymers
- Realastic (poly vinyl chloride)
- Mediplas (polyvinyl acetate chloride)
- epithane 3
1. Acrylic resin
Preferred for restoring
defects which require
e.g. fabrication of
• Useful in cases of
defects where relining is
1. Easy to work with & to maintain.
3. Easy to reline with a tissue conditioner or reliner.
4. Both extrinsic & intrinsic coloring can be
5. Compatible with most adhesive system & can be
2. Does not have the feel of skin.
3 High thermal conductivity.
4. Poor margin esthetics.
5. Surface gloss present. BEUMER
Cross linked co-polymer of methacrylics and acrylics.
Consists of base powders and stain concentrates,
Shade guide is provided for base shade powders and
Produces a soft, resilient skin with a spongy central
mass, light weight
The sculptured wax is weighed to achieve the
recommended ratio according to the weight ratio
In 1943 Tylman claimed that MMA could be
combined with plasticizer ( PALAMED)
Plasticized MMA resin has been formulated
with a foaming agent.
Palamed must be carefully proportioned
because too much will result in a stiff heavy
unstable product or too little will result in
incomplete filled mold with large pores.
Use of visible light cure resin system in
VLC resins underwent polymerization without
substantial exothermic reaction. Biologic testing
they are non toxic & biocompatible.
Useful in the replacement of large full-
thickness defects in the cranium & other
Also used in mandibular augmentation
2. VINYL POLYMERS &
Most widely used plastics for fabrication of MFP
Copolymers of vinyl chloride & vinyl acetate
Properties are superior to those of natural rubbers
in flexibility & resistance to sunlight & aging
Clinical usefulness may extend from 1-6 months
Introduced in 1940.
Vinyl resins are relatively rigid in their pure state,
made flexible by addition of plasticizers.
In its plastisol stage the material is a thick liquid
formed by dispersion of small vinyl particles in
1. Inexpensive & easy to manipulate
2. Can be remade by resoftening & reheating.
3. Hydrophilic properties.
1. Prosthesis made from plastisol looses its
flexibility with aging & become hard &
2. Degradation & destruction by UV light.
3. Linotype Metal molds are used which are
4. Stains easily
Elastomers have been used for over 50 years now
to fabricate facial prostheses for individuals
missing facial anatomy due to resection, trauma or
even congenital anomalies.
a) Polyurethane elastomer
• ……But only
Epithane-3 facial restorations.
3 component system
Part A - polyol
Part B- isocyanate
Part C- initiator such as dibutyltin dilaurate or
Varying amount of isocyanates will change the physical
properties of final products.
- They can be made elastic without compromising edge
- Flexibility well suited to defects with movable tissue
- Colored extrinsically & intrinsically
- Superior cosmetic results.
- Difficult to process consistently
- Isocyanate is moisture sensitive & toxic
- The presence of moisture in the air, leads to
production of CO₂ resulting in porous elastomer.
Water contamination is difficult to control
Requires thorough dehydration before processing if
stone molds are used
Poor compatibility with existing adhesive systems
Difficulty in clearing adhesive from prosthesis.
Not color stable.
Clinical usefulness less than 6 months ( approx.
• Properties of silicone
• Disadvantages of silicone
• Classification of silicone
• HTV silicone
• RTV silicone
• Advantages of HTV over RTV
b) Silicone elastomer
The silicon elastomers -- introduced -1946,
Silicones are a combination of organic and
The first step in their production is the
reduction of silica to elemental silicon.
Then by various reactions the silicon is combined
with methyl chloride to form Dimethyl dichloro
siloxane, which, when it reacts with water,
forms a polymer
Polymers – translucent , watery , white fluids .
Fillers -- additional strength.
Anti-oxidants & vulcanizing agents -- transform
the raw mass from a plastic to a rubbery resin
Cross linking makes the silicones especially
resistant to degradation from ultra-violet
Disadvantages of silicones
Receive colors poorly or with difficulty
Some are opaque resulting in prosthesis that are
cold and lifeless.
Poor wet ability
Good only with silicone adhesives
Classification of silicone
• Based on the Mechanism
• Acc. to Application
• Based on chemistry
JIADS VOL 1 ISSUE 2 APRIL- JUNE 2005;
Based on the
• Implant grade
• Medical grade
- external use
• Clean grade
• Methyl vinyl
• Fluoro dimethyl
JIADS VOL 1 ISSUE 2 APRIL- JUNE 2005;
1. 1 or 2 component system with putty like
2. 2 primary catalysts - platinum salt (addition)
and dichlorobenzoyl peroxide (condensation).
3. Filler - very pure, finely divided silica (size
4. Processing of heat cured silicones requires
sophisticated instrumentation and high
• Excellent thermal stability
• Biologically inert
• Color stable when exposed to
• Opaque, lifeless
• Not adequate
• Metal Molds
Silastic 370, 372, 373
These silicones can be preformed into various
shapes for alloplastic implantation or facial
Available as clear solutions
A viscous silicone polymer that includes a filler
& a catalyst –
Stannous octoate is the most common catalyst .
Fillers usually diatomaceous earths - improve
strength, but significant loss of translucency
occurs. This problem primarily exists typically
with Silastic 382 & 399.
2 types of RTV
- Color stable
- Biologically inert
- Easier to process
- Retain physical & chemical properties at wide range
- Stone molds can be used
- Poor edge strength
- Cosmetic appearance of the material -- inferior to
that of polyurethanes, acrylic resins, polyvinyl
HTV OVER RTV
1. Less chances of air bubble entrapment,
since hand mixing of catalyst & pigments
with the elastomer is avoided.
2. Increased tear strength mechanical
durability, & chemical resistance.
3. Increased biocompatibility and
The purpose -- reduce the weight of the
After the silicone is processed, the gas is
eventually released leaving a spongy material.
ADV--The formation of the bubbles within the
mass can cause the volume to increase by as much
as 7 times.
However, the foamed material has reduced
strength and is susceptible to tearing. This
weakness can be partially overcome by coating the
foam with another silicone
MDX 4 - 4210
Low temperature, vulcanizing
Provided as a two component
The polymerization reaction
is addition reaction with no
Very colour stable
JIADS VOL 1 ISSUE 2 APRIL- JUNE 2005;
Advantages of this material
Most importantly it has a high tear strength
compared to RTV silicones
Unusually thin edges can be designed in a
prosthesis without the risk of damage during
wear & removal.
Accelerated aging tests have shown that the
elastomer is very color stable.
JIADS VOL 1 ISSUE 2 APRIL- JUNE 2005;
Arylene silicone polymer - synthesized &
formulated as a pourable, viscous, RTV liquid
Transparent ,Reinforced with silica fillers.
Three component kit –
Tetrapropoxysilane (cross linking agent) and
JIADS VOL 1 ISSUE 2 APRIL- JUNE 2005;
Unusual combination of high-tensile strength &
low modulous (relative to other conventional RTV
Improved edge strength
Feel like skin
JIADS VOL 1 ISSUE 2 APRIL- JUNE 2005; BEUMER
MPDS -- Silicone Block Copolymers
(Methacryloxy propyl-terminated poly dimethyl siloxane)
It is introduced to improve some of the
drawbacks of silicone elastomers, such as
decreased tear strength, low percent elongation
& bacterial growth over prosthesis.
Methacrylate - (ADHEOPHILIC) reduces the
hydrophobicity which enhances the adhesive
bond strength to non-silicone-based adhesives
Fluoro elastomer has been developed for use as
a resilient denture liner (NovusTM, Hygienic
It has the potential to be used as a
maxillofacial prosthetic material.
New organosilicone maxillofacial
Lai, wang, Delong, Hodges.
The purpose of this study is to evaluate the physical properties
of new prosthetic materials based on methacryloxypropyl
terminatedpolydimethylsiloxane (MPDS-MF) and to compare
the properties with those of A-2186.
The hardness of MPDS-MF is similar to A-2186. However,
tensile strength, tear strength, ultimate elongation, and
adhesive bonding strength of MPDS-MF are higher than those
Dental Materials 18 (2002) 281 ±286
Effect of nano-oxide concentration on the mechanical
properties of a maxillofacial silicone elastomer,
The purpose of this study was to evaluate the effect of different
concentrations of nanosized oxides of various composition on the
mechanical properties of a commercially available silicone
Nanosized oxides (Ti, Zn, or Ce) were added in various
concentrations to a commercial silicone elastomer (A-2186),
Incorporation of Ti, Zn, or Ce nano-oxides at
concentrations of 2.0% and 2.5% improved the overall
mechanical properties of the silicone A-2186
(J Prosthet Dent 2008;100:465-473)
Defined as one that has a distribution of pigments
equivalent to that of human skin and whose overall
colour appears to change precisely as does that of a
human skin under all types of illumination. – Chalian
Coloration of the prosthesis varies with the
materials used and the preference of the clinician.
Basic skin tones should be developed into a shade
guide for the materials that are used.
The base shade selected should be slightly lighter
than the lightest skin tones of the patient because
the prosthesis will darken by either extrinsic or
Coloration techniques can be divided into 3 groups:
Extrinsic, intrinsic or combination technique.
The combination technique is widely used because it
produces prosthesis with a more natural appearance.
The color match of the prosthesis depends largely on the
skill of the clinician, color activity of the individual and light
At present the procedure is done using an empirical trial
and error method having no standardization for future
Intrinsic coloration is the color applied within
the mold during the casting procedure.
A three dimensional quality is accomplished by
incorporating subsurface details such as
blood vessels, freckles and moles.
Knowledge of primary, secondary and
complementary colors is helpful in selection of
Primary Color Secondary Color
1) Red Red+Yellow=orange Red-Green
2) Yellow Yellow+blue=Green Yellow-Violet
3) Blue Blue+Red=Violet Blue-Orange.
Spectrophotometers used to measure patient skin
Kaolin Powder Calcined White
G-102 used to create opacity with
Basic Skin Pigments for
Flocking / Fibres for intrinsic stains Veins
Accelerated color change in a maxillofacial
elastomer with and without pigmentation
This study attempted to determine whether predictable color
changes occur when 3 pigments are individually incorporated into
a specific silicone elastomer.
The materials included an RTV elastomer; 1 natural inorganic
pigment, burnt sienna and 2 synthetic organic pigments, Hansa
yellow and alizarin red.
Acceleration was achieved…
If left indoors with exposure to normal levels of daylight, the
observed color change of the specimens would likely occur but
take more time.
(J Prosthet Dent 2001;85:614-20.)
Once the base color is identified, laminar glazes are
applied to simulate the skin complex appearance.
Laminar glazes are layers of color painted into the
mould before packing the base color and this is
combined with placement of threads and flocks for
blood vessel simulation.
Common colors for laminar glazes are:
Red bluish glaze .
Golden tan glaze
Dark brown glaze
Opaque Yellow White color
Dark blue or purple
Opaque, Pink to red helix color
Base color is compared to patient
skin with red bluish glaze , layered
over a base color
Red bluish glaze is painted into the first layer of
Tweezers and periodontal
probe to place thread for blood
Syringe used to inject
silicone into the helical group
mould prior to packing the
It is more predictable
It should be used sparingly
Apply the extrinsic pigments in small
amounts and on the surface of the
prosthesis in a stippled fashion.
Curing can be done by placing in an
air-circulating oven at 90°centigrade.
Additional glazes are applied and
cured by using air drier.
Application of extrinsic color Blending the Seam
Application of kaolin to Compressed air used to
Cured surface of the prosthesis eliminate excess kaolin
In vitro evaluation of color change in maxillofacial elastomer
through the use of an ultraviolet light absorber and a
hindered amine light stabilizer.
This study evaluated color stability when an ultraviolet light
absorber and hindered amine light stabilizer were mixed in the
maxillofacial elastomer containing either organic or inorganic
The materials used were an RTV silicone elastomer, 1 natural
inorganic dry-earth pigment (burnt sienna) and 2 synthesized
organic pigments (hansa yellow and alizarin red), ultraviolet light
absorber (UVA) and hindered amine light stabilizer (HALS).
UVA and HALS were shown to be effective in retarding color
J Prosthet Dent. 2004 May;91(5):483-90
Problem with adhesives
Adhesives are expected to retain prostheses
during ordinary & extreme facial expressions,
build-up of sebaceous secretions & water &
change of weather conditions.
Most facial prostheses are retained with a
medical grade adhesive.
Selection depends -- Biocompatibility,
-- Retentive properties
-- Ease of applicability
-- Removal on daily basis
-- Nature of the material
from which prosthesis is
(double-coated polyethylene, 3M surgical tape)
These materials are backing strips composed of
cloth, paper, film, foil, or laminate coated
with a pressure-sensitive adhesive.
The bond weaker than that of rubber adhesives.
Advantages - the ease of application & cleaning
Indication for biphasic tape is with materials
that have poor flexibility & nonmobile tissue
Are a form of RTV silicone dissolved in solvent.
Once applied, the solvent evaporates & a tacky
surface forms that form bond with another
Despite their low adhesive strength, they have
good resistance to moisture & weathering with
low water sorption
Acrylic resin emulsions
Composed of acrylic resin dispersed in water
solvent when evaporated, leaves a rubber-like
Other materials -- synthetic rubber, vinyl
acetate, reclaimed rubber, vinyl chloride,
styrene, & methacrylic
Penetration & wetting -- controlled by addition
of surfactants or altering the particle size of
Increasing the viscosity -- prevent penetration
into porous surfaces.
Problems with Adhesives
Patients with poor manual dexterity or
coordination may not be able to apply the
adhesive or position the prosthesis in a
Margins adjacent to mobile tissue require
constant reattachment with facial movements.
Allergic or irritational responses may persist.
Some aromatic base adhesives may curl thin
Poor hygiene limit the wearing of a prosthesis ,
because of interference with adhesive qualities.
Routine removal of adhesive -- remove the
No single maxillofacial material is ideal for every
1. Continued effect of sunlight and vascular
dilatation & contraction on the natural tissues
cannot be duplicated in the prosthesis.
2. Variations of skin tone when the patient is
exposed to different light sources (e.g.,
incandescent, fluorescent, & natural light)
cannot be duplicated in the prosthesis
3. The prosthesis cannot duplicate the full facial
movement of the non defective side
4. Varying physiologic conditions of the patient
in everyday living (e.g., lack of sleep, infectious
diseases, and edema resulting from
interrupted lymph drainage caused by surgery)
cannot be duplicated in the prosthesis.
5. Inflammation caused by recent surgery, which
subsides with time -- necessitates remaking
6. Lack of predictability of the life of the
prosthesis, because of variations among
patients (i.e., secretions, smoking, and
1. “Maxillofacial Prosthetics”, Chalian
2. “Maxillofacial prosthetics” Laney WR
3. “Clinical maxillofacial Prosthetics” Thomas D Taylor
4. Oral and maxillofacial rehabilitation by Buemer.
5. Robert Sanchez, comparision of physical properties of two
types of polydimethyl siloxane, MDX4-4210 and new
material A-2186 JPD 1992:67(5);679
6. Effect of nano-oxide concentration on the mechanical properties
of a maxillofacial silicone elastomer, Ying Han, DDS, MS,a
Sudarat Kiat-amnuay, DDS, MS,b John M.Powers, PhD,c and
Yimin Zhao, DDS, PhDd, J Prosthet Dent 2008;100:465-473
7. New organosilicone maxillofacial prosthetic materials
Lai, wang, Delong, Hodges, Dental Materials 18 (2002) 281 ±286
8. Accelerated color change in a maxillofacial elastomer with and
without pigmentation, John J. Gary, Eugene F. Huget and Larry D.
Powell, J Prosthet Dent 2001;85:614-20.
9. In vitro evaluation of color change in maxillofacial elastomer
through the use of an ultraviolet light absorber and a hindered
amine light stabilizer, J Prosthet Dent,2004 May;91(5):483-90
10. An in vivo evaluation of adhesives used in
extraoral maxillofacial prostheses.
Haug SP, Richard GE, Margiotti E, Winkler MM, Moore
DJ, J Prosthodont 1995 Mar;4(1):11-5.
11. . Mechanical behavior of three maxillofacial prosthetic
adhesive systems: A pilot project, John F. Wolfaardt, Victor
Tam, M.Gary Faulkner, Narasimha Prasad, The journal of
prosthetic Dentistry,vol 68;6:December 1992, Pages 943–
12. . JPD 1984:51(4):523-226.