6.maxillofacial prosthesis materials

7/27/2019 6.Maxillofacial Prosthesis Materials

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Maxillofacial Prosthesismaterials

Presenter : Dr. Sumit Sethi

Guide : Dr. Dilip Kakade

03-04-06


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Contents

Introduction

History Classifications

Ideal properties

Individual material & their advantages &disadvantages

Comparison of physical properties

Technique of fabrication Limitations & degradation of the material

Conclusion

References


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Introduction


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History Before 1600 AD- ancient Chinese culture

Tycho Brahe (1546-1601)- nose from gold.

Ambroise Pare (1510-1601)- nose from gold, silver,paper.

Pierre Fauchard (1678-1761)- silver mask.

William Morton (1819-1868)- enameled porcelain.

Claude Martin (1889)- ceramic


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History

1900-1940

Uphamvulcaniterubber.

1905 Ottofy, Baird &

Baker- vulcaniterubber.

1913Gelatin-

glycerin compounds.

Bulbulian & Clarke -

Latex Vulcanite prosthesis given to Sigmond

Freud (Austrian psychiatrist) in 1923.


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History 1937- Acrylic resin.

Tylmanresilient Vinyl copolymer

1960 to 1970-

BarnhartSilicone & acrylic resin polymer stains.

1970 to 1990-

Lontz - modified Polysiloxane elastomers.

Lewis & CastleberrySiphenylenes.

Udagama & Drane- Silastic medical adhesive type A.

1990 to present-

Antonocci & Stansberrynew generation acrylic resin

Gettleman - Polyphosphazenes


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ClassificationClassification of materials used in Maxillofacial Prosthodontics

Impression

materials

Materials for

fabrication

Pigmentation

materials

Auxiliary

materials

Materials for

Retention

Composition

Macro-

cellular foam

Plaster of

Paris

Plaster

bandage

Alginate

Mould

making

Pattern

materials

Prostheticmaterials

Flasks

Separating

medium

Comfeel

Stellon

crown

Silastic

foam

Aerosil 130

Extrinsicsealant

Others

Implants

Magnets

Adhesives

Primers

Silicone

putty

Extrinsic

Intrinsic


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Classification of MaxillofacialProsthesis materials

According to Beumer:

1. Acrylic resins.

2. Acrylic copolymers.

3. Polyvinyl chloride & copolymers.

4. Chlorinated polyethylene.

5. Polyurethane elastomers.

6. Silicone elastomersHTV, RTV, Foamingsilicones.

7. New materials- Silicone block copolymers,

Polyphosphazenes.


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Classification of MaxillofacialProsthesis materials

According to ANUSAVICE:

1. Latex- a tripolymer of Butyl acrylate, Methyl

methacrylate & Methyl methacrylamide.

2. Vinyl Plastisols.

3. Silicone Rubbers.

4. Polyurethane Polymers.


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Ideal properties 1. Ideal Physical & Mechanical properties:

a. Dynamic properties comparable to tissues.b. High edge strength, high elongation, high resistance

to abrasion, high tear strength & high tensilestrength.

c. Low coefficient of friction, low glass transitiontemperature, low specific gravity, low surfacetension & low thermal conductivity.

d. Odorless, Non-inflammable, No water sorption.

e. Translucent.

f. Softness compatible to tissue & variable flexibility

without addition of leachable plasticizer.


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Ideal properties 2. Ideal Processing characteristics:

a. Adjustability.b. Chemically inert after processing.

c. Dimensionally stable during & after processing.

d. Ease of intrinsic & extrinsic coloring.e. Ease of mold fabrication & processing.

f. Ease of repair & refabrication if needed.

g. Fidelity of detail reproduction.h. High viscosity for maintaining even dispersion of

colorants.

i. Long shelf life & working time.


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Ideal properties

2. Ideal Processing characteristics: (contd)

j. Low viscosity for ease of processing.

k. Low processing temperature.

l. Low sensitivity to contamination during processing.m. Non-inflammable, non-toxic & non-porous.

n. No polymerization by-products.

o. Reusable molds.p. Retain intrinsic & extrinsic coloration during use.

q. Short processing time.


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Ideal properties 3. Ideal Biological properties:

a. Compatible with supporting tissues.b. Non allergic & non toxic.

c. Cleansable with disinfectants without losing detailsat surface or margins.

d. Color stability & dimensional stability.

e. Flexibility comparable to tissue & stable at hightemperatures.

f. Inert to solvents & skin adhesives.

g. Resistance to environmental discoloration & growthof microorganisms.

h. Inexpensive.


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Individual material1. ACRYLIC RESINS:

- used in areas with littlemovement. (Orbital or

Ocular etc)

Advantages: readily available, easy incoloring, good strength, compatiblewith adhesives, long service, colorstability, easily repaired or relined.

Disadvantages: rigidity, discomfort,high thermal conductivity, no

duplication possible.


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Individual material

2. ACRYLIC COPOLYMERS:

Advantages: soft & elastic.

Disadvantages:poor edge strength, degrade in

sunlight, processing & coloration is difficult, gets

stained easily .

- Antonucci & Stansbury reported new generation

development in this.


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Individual material

3. POLYVINYL CHLORIDE (PLASTISOLS) &

COPOLYMERS: ( Realistic, Mediplast,Prototype III)

- a rigid , clear, tasteless & odorless- glass transition temperature higher

- plasticizers are added

- cross linking agentsRecently a copolymer5%to 20% Vinyl acetate in it.

It is more stable, more flexible but less chemicallyresistant.


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Individual material

3. POLYVINYL CHLORIDE (PLASTISOLS) &

COPOLYMERS: ( contd)

Advantages: flexible, adaptable to coloration to yield

good appearance.

Disadvantages: leaching of plasticizers, tear easily,

easily stained, degrade easily, soil easily, metalmolds required, short service life, poor dimensional

stability.


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Individual material

4. CHLORINATED POLYETHYLENE:

- Lewis & Castleberry

- similar to Polyvinylchloride in both chemical

composition & physical properties.

- Gettleman also reported (CPE 726/19-15)

- clinical trials just initiated


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Individual material

5. POLYURETHANE ELASTOMERS:

- Diisocyanate + Polyol

- processing (1000C)

Advantages: elastic (without compromising edge

strength), flexible, easy coloration, superior

cosmetic results.

Disadvantages: difficult to process, moisture

sensitive, no color stability, service life less, poor

compatibility with adhesives, toxic.

initiator


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Individual material

6. SILICONES:

- Production

- dimethyl dichlorosiloxane + water

Classified into four groups:i) Implant grade

ii) Medical grade

iii) Clean grade

iv) Industrial grade


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Individual material

a. HEAT VULCANIZED SILICONES (HTV) :

- Polydimethyl vinyl siloxane copolymer with approx.

0.5% vinyl side chains, 2,4-dichlorobenzoyl

peroxide as an initiator & a silica filler obtainedfrom burning methyl silanes.

- processing temperature ( 2200C).

- difficult to pigment.


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Individual material

i. SILASTIC 370, 372, 373, 4-4514, 4-4515:

- white opaque material, highly viscous.

- dichlorobenzoyl peroxide or platinum salt as catalyst

- fillers added to harden (silica)

-Advantages: excellent thermal stability, color

stability, biologically inert.

-Disadvantages: less elastic, low edge strength,

opaque & lifeless, difficult to color extrinsically,

require metal molds.


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Individual material

ii. PDM SILICONES:

- Lontz and Schweiger& Lontz

- Abdelnnabi evaluated properties


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Individual material

iii. Q7-4635, Q7-4650, Q7-4735, SE-4524U:

- a new generation evaluated by Bell

- single component system

- unlimited shelf life


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Individual material

b. ROOM TEMPERATURE VULCANIZED

SILICONES (RTV) :

- used more often then any other

- good physical & mechanical properties

- vinyl & hydride containing siloxanes

- chloroplatinic acid as ctalyst

- tetraethoxysilane as cross-linking agent

di id l i l


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Individual material

i. SILASTIC 382, 399 :

- stannous octoate catalyst & orthoalkyl silicate ascross linking agent

- Advantages: color stable, clear solutions, easy to

process, require stone molds

- Disadvantages: poor strength, difficult to color,

cosmetic results inferior

di id l i l


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Individual material

ii. MDX4-4210 :

- chloroplatinic acid catalyst & hydro-methyl siloxaneas cross-linking agent. (800C for 1 hour)

-Moore reported improved properties

Advantages: no reaction by-product,

increased elongation,

surface texture & shore hardness,

non-toxic, color stable,

simple processing,

compatible with adhesives

I di id l i l


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Individual material

iii. SILASTIC 891 (Silastic Medical Adhesive

Silicone Type A) :- Udagama & Drane

- translucent, non flowing, polymerizes in air

- Advantages: no need of molds, no catalyst,

compatible with wide range of colorants.

- in 1987 Udagama used it along with polyurethane

film to improve its edge strength.

- Farah suggested a combination of:

40% MDX4-4210 + 60% MED.A 891

I di id l t i l


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Individual material

iv. COSMESIL / SILSKIN 2 SYSTEMS :

- Woofaardt described it

- two curing system:

a) Platinum cure:

- utilizes vinyl terminated Silicone & a platinum

catalyst

- addition reaction so no by-products. Hence no

shrinkage

- poisoned by latex

- working time 1 hr & curing at 1000C for 1 hr

I di id l t i l


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Individual material

iv. COSMESIL / SILSKIN 2 SYSTEMS (contd) :

(b) Tin cure:

- utilizes hydroxy terminated silicone fluids & a Tin

catalyst

- condensation reaction so by-product is formed

- is very robust & cures against most substrates/

conditions

- working time 1hr & cures in 24 hr at room

temperature.

I di id l t i l


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Individual material

v. A-2186 (FACTOR II) :

- a recently developedmaterial initially showed

improved properties.

- but Haug reported that itdoesn't retain them when

subjected to

environmental variables.- two types of curing system

similar to Cosmesil

I di id l t i l


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Individual material

7. NEW MATERIALS:

(i) Silicone block copolymers:

- incorporates Polymethyl methacrylateinto Siloxane

blocks.

- more tear resistant

(ii) Polyphosphazenes:

- developed as a resilient denture liner

Ph i l ti


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Physical properties

Tensile strength

Maximum Elongation

Pants Tear energy

Dynamic Modulus

Ph i l ti (CRAIG)


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Physical properties (CRAIG)

Material Tensile

strength(psi)

Max. %

elongation

Pants tear

test(dynes/cm

106

Dynamic

modulus(MPa)

Plasticized

polyvinylchloride 3.99 215 4.3 4.32

Polyurethane 0.83 422 6.7 3.46

HTV 5.87 441 Doesn't tearbut stretches as

in tensile

4.66

RTV 4.20 445 Elongation. 2.12

Ph i l ti (BEUMER)


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Physical properties (BEUMER)Elastomer A-2186 Silastic 382 MDX4-4210 MDX4-4515 MDX4-4516

Manufacturer Factor II Dowcorning

Dowcorning

Dowcorning

Dowcorning

Color Translu-

cent

Gray Translucent Translucent Translucent

Shore hardness 25 43 >25 52 72

Tensile strength

(psi)

900 350 >550 1350 1175

%Elongation 650 160 >350 450 370

Tear strength

(psi)

90 NA 50 NA NA

Specific gravity 1.12 1.13 1.12 1.15 1.21

Ph i l ti (CHALIAN)


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Physical properties (CHALIAN)

Silastic

S-6508

Silastic 382 Silastic 399

Durometer 26 45 50

Tensile (psi) 785 300 525

%Elongation 490 100 230

Tear (psi) 65 20 29

M ld ki t i l


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Mold making materials

Silicones.

Surgical plaster of Paris- for investing of allprosthesis & blanking out undesired areas ofimpression models.

Kaffir D dental stone- for all impression models.

Beta Dur 700 hard stone- vacuum mixed & used as atopping investment as it is hard & protects finerecorded details. Its color allows easy placement of

localized color.

Plaster / pumice- 30/70 ratio used for blanking areasthat need to be free of silicone in the mold

(Keith Thomas)

Flasks


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Flasks

Two part rectangular Aluminium alloy flasks, selfclamping.

Available in sizes :Small 6 4 3 Medium 6 6 3/8 6 1/12Large 9 6 7 Shallow 8 5 2

(Keith Thomas)

i di


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Separating media

Soap- useful for two part plaster moulds, also ifused in a 5% solution may be used as a releasing

agent for silicone prosthesis.

Cold mould seal- all plaster moulds, also as a

releasing agent for silicone.

Medi-Mould wax mould sealant & releasing

agent- sealing porous mould surfaces. Release agent

for silicone.

Pattern materials


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Pattern materials

Waxes: hard, soft , skin colored etc.

- Baseplate wax , Korecta wax ,

Utility Wax

Clay

Materials for retention


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Double sided

adhesive tape

Primers & Adhesives

Mate ials fo etention


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Implants



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Adhesive magnet plate

Neo- mini magnets



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SpectaclesSprung steel head band

Other materials

Materials for Pigmentation


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Materials for Pigmentation

Extrinsic & intrinsic pigments.

Basic shades are mainly metal oxides like:

Nickel oxide - Brown

Manganese oxide - Lavender

Titanium oxide - Yellowish brown

Iron oxide - Brown

Copper oxide - Green

Auxiliary materials


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Auxiliary materials

Extrinsic sealant

Aerosil 130- to reduce shine & alter viscosity

Silastic foam dressing

Macrocellular foam

Stellon crown & bridge- to facilitate construction of

custom made finger nails.

Adhesive removers or solvents

Auxiliary materials


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Auxiliary materials

Comfeel ( skin conditioner)

- it is Ethoxyethyl acid copolymer ethyl acetate- creates an elastic protective barrier

- applied to clean skin & after 1-2 min it forms

a film.

Fabrication of the Prosthesis


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Fabrication of the Prosthesis

Master cast

Color matching/ intrinsic pigmentation

Wax / clay pattern

Impression

Try-in

Processing

Compression molding

Two part or three or four part mould

Investment

Surface / extrinsic pigmentation

Finishing

Limitations & Degradation


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Limitations & Degradation

Discoloration due to

- external environmental factors.- due to loss of external coloration.

Degradation of properties

- tear at margins

- change in surface texture

- elongation at margins

- deterioration of static & mechanical properties


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Conclusion

Ultimate challenge to a material is its clinicalperformance.

Laboratory testing should be correlated to

clinical performance.

Sweeney in 1972 & Lewis & Castleberry in

1980 gave specifications for maxillofacial

elastomer.

Future research:

- improving the properties to service life.

- color stable & better color matching.


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References

Prosthetic Rehabilitation - Keith Thomas

Maxillofacial Rehabilitation - Beumer & Curtis

Maxillofacial Prosthetics - Chalian

Restorative dental material - Craig

Philips science of dental materials - Anusavice

Oral cancer - Silverman Cosmesil & Factor II catalogue


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6.maxillofacial prosthesis materials

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