denture-base-resin-61697101-61697101.pdf
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About This Presentation
Denture base resins
Slide Content
Denture Base Resin
-Dr. Soham Prajapati
1°! Year Post Graduate,
Dept. of Prosthodontics
& Maxillofacial Prosthesis
Including Oral Implantology.
7/12/2013 & 9/12/2013
-Dr. Soham Prajapati
1°! Year Post Graduate,
Dept. of Prosthodontics
& Maxillofacial Prosthesis
Including Oral Implantology.
7/12/2013 & 9/12/2013
Definition
History
Classification
Dental polymers
Ideal requirements of Denture Base Resin
Principal ingredients of Denture Base Resin
Different Types Denture Base Resins
Properties of PMMA
Cytotoxicity of Denture Base Acrylic Resins
Recent Advances
Conclusion
References
History
Classification
Dental polymers
Ideal requirements of Denture Base Resin
Principal ingredients of Denture Base Resin
Different Types Denture Base Resins
Properties of PMMA
Cytotoxicity of Denture Base Acrylic Resins
Recent Advances
Conclusion
References
Definition
° DENTURE BASE: The part of a denture that
rests on the foundation tissues and to which
teeth are attached.
» RESIN: A broad term used to describe natural
or synthetic substances that form plastic
materials after polymerization.
-GPT8
° DENTURE BASE: The part of a denture that
rests on the foundation tissues and to which
teeth are attached.
» RESIN: A broad term used to describe natural
or synthetic substances that form plastic
materials after polymerization.
-GPT8
Key Points of DENTAL RESINS
+ ADA/ANSI Specification no 12 - Denture base
ADA
Accepted
resins.
« ISO 1567
American
ental
Association ®
SN International
Organization for
hw Standardization
+ ADA/ANSI Specification no 12 - Denture base
ADA
Accepted
resins.
« ISO 1567
American
ental
Association ®
SN International
Organization for
hw Standardization
History
© Skillfully designed dentures were made as
early as 700 BC using ivory and bone.
* Till 1800s, dentures were hand carved and
tied in place with
* Queen Elizabeth | and George Washington
suffered from tooth loss and unfit dentures.
George Washington's denture in the We
National Museum of Dentistry
© Skillfully designed dentures were made as
early as 700 BC using ivory and bone.
* Till 1800s, dentures were hand carved and
tied in place with
* Queen Elizabeth | and George Washington
suffered from tooth loss and unfit dentures.
George Washington's denture in the We
National Museum of Dentistry
History
* In 1774, Duchateaus and Dubois de Chemant
designed a full set of dentures that would not
rot.(made of porcelain.)
MINERAL PASTE TEETH
i
* In 1774, Duchateaus and Dubois de Chemant
designed a full set of dentures that would not
rot.(made of porcelain.)
MINERAL PASTE TEETH
i
History
+ Giuseppangelo Fonzi created a single
porcelain tooth held in place by a steel pin in
1808.
» Claudius Ash made an improved porcelain
tooth in 1837.
* Porcelain dentures moved to US in 1800s and
marketed on a large scale. Fit was eventually
improved as well.
+ Giuseppangelo Fonzi created a single
porcelain tooth held in place by a steel pin in
1808.
» Claudius Ash made an improved porcelain
tooth in 1837.
* Porcelain dentures moved to US in 1800s and
marketed on a large scale. Fit was eventually
improved as well.
History
« In 1700s, plaster of paris was introduced. It
was used to make a mold of the patient’s
mouth. This helped to make the dentures
precise.
* Swaged Gold was used as denture base for
those who could afford it.
« In 1700s, plaster of paris was introduced. It
was used to make a mold of the patient’s
mouth. This helped to make the dentures
precise.
* Swaged Gold was used as denture base for
those who could afford it.
History
+ Real breakthrough when vulcanized rubbe
was discovered by Charles Goodyear in 1840.
— Cheap
— Easy to work
— Hold the denture
* Vulcanite dentures were available in India
under British rule by British and other
European Dentists.
+ Real breakthrough when vulcanized rubbe
was discovered by Charles Goodyear in 1840.
— Cheap
— Easy to work
— Hold the denture
* Vulcanite dentures were available in India
under British rule by British and other
European Dentists.
Vulcanite
+ Contains 32 % sulphur and metallic oxides for
color.
Quiet hard to polish
Non-irritant Absorbs Saliva
Excellent Mechanical Properties Becomes unhygienic.
Unpleasant odor(when
processed)
Poor esthetics (opacity of rubber)
Dimensional changes.
+ Contains 32 % sulphur and metallic oxides for
color.
Quiet hard to polish
Non-irritant Absorbs Saliva
Excellent Mechanical Properties Becomes unhygienic.
Unpleasant odor(when
processed)
Poor esthetics (opacity of rubber)
Dimensional changes.
Nitrocellulose
Dimensionally stable
Excessive Warpage
High water absorption
Poor color stability
Contains unpleasant tasting plasticizer
Highly flammable
Dimensionally stable
Excessive Warpage
High water absorption
Poor color stability
Contains unpleasant tasting plasticizer
Highly flammable
Fig, 1015,
Other ae
Celluloid
— Was tried in place of rubber but didn’t prove best
of the material.
+ Porcelain
— It was tolerate by denture bearing mucosa, but
difficult to fabricate and easily broken.
¢ Phenol Formaldehyde
— Becomes dicolored and unesthetic and being
thermosetting, it is difficult to repair
Other ae
Celluloid
— Was tried in place of rubber but didn’t prove best
of the material.
+ Porcelain
— It was tolerate by denture bearing mucosa, but
difficult to fabricate and easily broken.
¢ Phenol Formaldehyde
— Becomes dicolored and unesthetic and being
thermosetting, it is difficult to repair
History
° In 1937 Dr. Walter Wright gave dentistry its
very useful resin.
* It was polymethyl methacrylate which proved
to be much satisfactory material tested until
now.
« By 1946, 98% of all denture bases were
fabricated from PMMA.
° In 1937 Dr. Walter Wright gave dentistry its
very useful resin.
* It was polymethyl methacrylate which proved
to be much satisfactory material tested until
now.
« By 1946, 98% of all denture bases were
fabricated from PMMA.
Classification
* According to ISO 1567
— Type 1
+ Class 1 Heat processing polymers, powder and liquid
* Class 2 Heat processed (plastic cake)
— Type 2
* Class 1 Autopolymerized polymers, powder and liquid
* Class 2 Autopolymerized polymers (powder and liquid pour
type resins)
— Type 3 Thermoplastic blank or powder
— Type 4 Light Activated Materials
— Type 5 Microwave-Cured Material
Applied Dental Materials, 8!" edition,
John F McCabe & Angus W. G. Walls
* According to ISO 1567
— Type 1
+ Class 1 Heat processing polymers, powder and liquid
* Class 2 Heat processed (plastic cake)
— Type 2
* Class 1 Autopolymerized polymers, powder and liquid
* Class 2 Autopolymerized polymers (powder and liquid pour
type resins)
— Type 3 Thermoplastic blank or powder
— Type 4 Light Activated Materials
— Type 5 Microwave-Cured Material
Applied Dental Materials, 8!" edition,
John F McCabe & Angus W. G. Walls
Classification
* Based on the usage:-
— Temporary Denture Base Resin
« E.g. Self Cure Acrylics
+ Shellac base plate
* Base plate wax
+ Injection Molded resins
+ Metallic Bases
— Permanent Denture Base Resin
« E.g. Heat Cure Denture Base
+ Light Cures Resins
* Pour Type Resins
* Based on the usage:-
— Temporary Denture Base Resin
« E.g. Self Cure Acrylics
+ Shellac base plate
* Base plate wax
+ Injection Molded resins
+ Metallic Bases
— Permanent Denture Base Resin
« E.g. Heat Cure Denture Base
+ Light Cures Resins
* Pour Type Resins
Classification
* Based on the METHOD USED FOR ITS
ACTIVATION:-
— Chemically activated
— Heat activated
— Light activated
* Based on the METHOD USED FOR ITS
ACTIVATION:-
— Chemically activated
— Heat activated
— Light activated
DENTAL POLYMERS
* Polymer is chemical compound consisting of
large organic molecules formed by the union
of many repeating smaller monomer units.
666
606-6
686
Individua: mers Polymer
* Polymer is chemical compound consisting of
large organic molecules formed by the union
of many repeating smaller monomer units.
666
606-6
686
Individua: mers Polymer
* Polymerization occurs through a series of chemical reactions
by which the macromolecule, or the polymer, is formed from
large numbers of molecules known as monomers.
« TYPES:-
— CONDENSATION POLYMERIZATION
— ADDITION POLYMERIZATION
polymer
by which the macromolecule, or the polymer, is formed from
large numbers of molecules known as monomers.
« TYPES:-
— CONDENSATION POLYMERIZATION
— ADDITION POLYMERIZATION
polymer
CONDENSATION POLYMERIZATION
* TWO GROUPS
— Those in which polymerization is accompanied by
repeated elimination of small molecules. The
process repeat itself and form macromolecules.
E.g. water, halogen acids, ammonia, etc.
CONDENSATION POLYMER
o o o o
ee ll il
> il >
(¿HO —CH, -c-ofñi + HO-CH - -€ fi —> 4 0-CH,-C nt n + HO
hi a
/
ts CH, _/ iy CH,
mu. u repeating unit
* TWO GROUPS
— Those in which polymerization is accompanied by
repeated elimination of small molecules. The
process repeat itself and form macromolecules.
E.g. water, halogen acids, ammonia, etc.
CONDENSATION POLYMER
o o o o
ee ll il
> il >
(¿HO —CH, -c-ofñi + HO-CH - -€ fi —> 4 0-CH,-C nt n + HO
hi a
/
ts CH, _/ iy CH,
mu. u repeating unit
— Those in which functional groups are repeated in
the polymer chains. The polymers are joined by
functional groups. Formation of a by-product is
not necessary. E.g. polyurethane.
Not widely used in DENTISTRY
the polymer chains. The polymers are joined by
functional groups. Formation of a by-product is
not necessary. E.g. polyurethane.
Not widely used in DENTISTRY
ADDITION POLYMERIZATION
« All resins employed extensively in dental
procedure are produced by addition
polymerization.
« No change in chemical composition and no by-
products are formed.
atmbio.en.alibaba.com
« All resins employed extensively in dental
procedure are produced by addition
polymerization.
« No change in chemical composition and no by-
products are formed.
atmbio.en.alibaba.com
How??
» Starting from an active centre, one molecule
at a time is added and a chain rapidly builds
up, which can grow almost indefinitely as long
as the supply of building blocks are available.
dd
_ BO
>— a >
> aa
BC
2
» Starting from an active centre, one molecule
at a time is added and a chain rapidly builds
up, which can grow almost indefinitely as long
as the supply of building blocks are available.
dd
_ BO
>— a >
> aa
BC
2
Chemical Stages of Polymerization
4 Stages:-
* Induction
° Propagation
+ Chain Transfer
° Termination
4 Stages:-
* Induction
° Propagation
+ Chain Transfer
° Termination
INDUCTION
Induction or initiation period is the time
during which the molecules of the initiator
becomes energized or activated and start to
transfer the energy to the monomer.
Induction or initiation period is the time
during which the molecules of the initiator
becomes energized or activated and start to
transfer the energy to the monomer.
« Three induction systems:-
— Heat Activation
— Chemical Activation
— Light Activation
* Heat Activated:- The free radical liberated by
heating benzoyl peroxide will initiate the
polymerization of methyl methacrylate
monomer. e.g. Denture base Resins
— Heat Activation
— Chemical Activation
— Light Activation
* Heat Activated:- The free radical liberated by
heating benzoyl peroxide will initiate the
polymerization of methyl methacrylate
monomer. e.g. Denture base Resins
Light Activated:-
— Photons of light energy activate the initiator to
generate free radicals. e.g. composite resin.
Chemical Activated:-
— System consists of at least two reactants, when
mixed they undergo chemical reaction and
liberate free radicals, e.g. Self Cured Resin
— Photons of light energy activate the initiator to
generate free radicals. e.g. composite resin.
Chemical Activated:-
— System consists of at least two reactants, when
mixed they undergo chemical reaction and
liberate free radicals, e.g. Self Cured Resin
INDUCTION
R—R + external energy > 2 Re
an
Initiator (BPO)
Fig. 7-7. Activation (heat or chemical) of benzoyl p
bond is broken, and the electron pair is split between
oxygen of the free radical symbolizes the unpaired ele
R—R + external energy > 2 Re
an
Initiator (BPO)
Fig. 7-7. Activation (heat or chemical) of benzoyl p
bond is broken, and the electron pair is split between
oxygen of the free radical symbolizes the unpaired ele
INDUCTION
NITIATION
PROPAGATION
* Once the growth has started, the process
continues with considerable velocity.
* Theoretically, the chain reactions should
continue with evolution of heat until all the
monomer has been changed to polymer.
+ Actually, the polymerization is never
complete.
* Once the growth has started, the process
continues with considerable velocity.
* Theoretically, the chain reactions should
continue with evolution of heat until all the
monomer has been changed to polymer.
+ Actually, the polymerization is never
complete.
PROPAGATION
RH,C—CH,» + H,CCH, + RH,C—CH, IL C= Cis
RH,C-CH,—H,C-CH o + H,C=CH, +
RC (CH, —H,C),—CH ee
RH,C—CH,» + H,CCH, + RH,C—CH, IL C= Cis
RH,C-CH,—H,C-CH o + H,C=CH, +
RC (CH, —H,C),—CH ee
El Carbon
E Hydrogen
E Hydrogen
CHAIN TRANSFER
The chain termination can also result from
chain transfer. Here, the activated state is
transferred from an activated radical to an
inactive molecule, and a nucleus of growth is
created.
The chain termination can also result from
chain transfer. Here, the activated state is
transferred from an activated radical to an
inactive molecule, and a nucleus of growth is
created.
CHAIN TRANSFER
Fig. 7-10 Chain transfer occurs when a free radical approaches a methyl methacrylate molecule and
donates a hydrogen atom to the methyl methacrylate molecule This causes the free ra to rearrange
to dom Taube ond and become unicación, and the MMA monomer to forma Wee taiical Thal can
PACS Tan propagation Wacken,
Fig. 7-10 Chain transfer occurs when a free radical approaches a methyl methacrylate molecule and
donates a hydrogen atom to the methyl methacrylate molecule This causes the free ra to rearrange
to dom Taube ond and become unicación, and the MMA monomer to forma Wee taiical Thal can
PACS Tan propagation Wacken,
CHAIN TRANSFER
Fig. 7-11 Another type of chain tanger ¿cur when à propagating chain interacts with the
passivated segment that was formed in Figure 7-10, During this interaction, the passive segment
becomes active, while the active segment becomes passive:
Fig. 7-11 Another type of chain tanger ¿cur when à propagating chain interacts with the
passivated segment that was formed in Figure 7-10, During this interaction, the passive segment
becomes active, while the active segment becomes passive:
TERMINATION
* The chain reaction can be terminated either
by direct coupling or by exchange of hydrogen
atom from one growing chain to another.
* The chain reaction can be terminated either
by direct coupling or by exchange of hydrogen
atom from one growing chain to another.
Termination
Termination
ken ey frre radical approach each other, a new double bond may be formed on the
a dragon ate ho the other lore rad al
ken ey frre radical approach each other, a new double bond may be formed on the
a dragon ate ho the other lore rad al
COPOLY MERIZATION
* The macromolecule may be formed by
polymerization of a single type of structural
unit.
* In order to improve the physical properties, it
is often advantageous to use two or more
chemically different monomers as starting
materials. COPOLYMER EXAMPLES
Monomer-1 = —
Random copolymer
= De Dale Se Oe > +
Alternating copolymer
- ar De ir are a >
Block copolymer =
-rrrr ee ee
* The macromolecule may be formed by
polymerization of a single type of structural
unit.
* In order to improve the physical properties, it
is often advantageous to use two or more
chemically different monomers as starting
materials. COPOLYMER EXAMPLES
Monomer-1 = —
Random copolymer
= De Dale Se Oe > +
Alternating copolymer
- ar De ir are a >
Block copolymer =
-rrrr ee ee
* The polymer thus formed may contain units of
these monomers. Such a polymer is called a
copolymer and its process of formation is
known as copolymerization.
1 | 7177777777 7900000000008
"OOO 777100’ 000 ' 0000
@ Monomer A 0) Monomer B
these monomers. Such a polymer is called a
copolymer and its process of formation is
known as copolymerization.
1 | 7177777777 7900000000008
"OOO 777100’ 000 ' 0000
@ Monomer A 0) Monomer B
Types of COPOLYMER
° There are three different types:-
+ RANDOM TYPE
+ GRAFT TYPE
* BLOCK TYPE
Block Copolymers
Gradient Copolymers
Random Copolymers
° There are three different types:-
+ RANDOM TYPE
+ GRAFT TYPE
* BLOCK TYPE
Block Copolymers
Gradient Copolymers
Random Copolymers
RANDOM TYPE
* In random type of copolymer the different
monomers are randomly distributed along the
chain.
waves ABBABABAAAAAABBABABABBBBBABBABBAB....
—A—A—B—A—B—B—A—B—A—A—B—B—B—A—
random copolymer
* In random type of copolymer the different
monomers are randomly distributed along the
chain.
waves ABBABABAAAAAABBABABABBBBBABBABBAB....
—A—A—B—A—B—B—A—B—A—A—B—B—B—A—
random copolymer
GRAFT TYPE
* Sequence of one of the monomers are grafted
onto the ‘backbone’ of the second monomer
species.
| |
h h
i i
ste
paies ke
Pe a a, „a, en
graft copolymer
* Sequence of one of the monomers are grafted
onto the ‘backbone’ of the second monomer
species.
| |
h h
i i
ste
paies ke
Pe a a, „a, en
graft copolymer
BLOCK TYPE
° Identical monomer units occur in relatively
long sequences along the main polymer chain.
+s AAAAABBBBBAAAAABBBBBAAAAABBBBBAAAAA.....
° Identical monomer units occur in relatively
long sequences along the main polymer chain.
+s AAAAABBBBBAAAAABBBBBAAAAABBBBBAAAAA.....
IMPORTANCE OF COPOLYMERIZATION
* It is to better the physical properties of resins.
+ Many useful resins are manufactured by
copolymerization.
en, "a
of id
Monomer + Cross-linker Introduction of cross-links
into polymers
Monomer Gross-linked Gels Polymer Cross-linked Gels:
* It is to better the physical properties of resins.
+ Many useful resins are manufactured by
copolymerization.
en, "a
of id
Monomer + Cross-linker Introduction of cross-links
into polymers
Monomer Gross-linked Gels Polymer Cross-linked Gels:
CROSS-LINKING
* The formation of chemical bonds or bridges
between the linear polymer is referred to as
CROSS-LINKING.
* It forms a three-dimensional (3D) network.
* The formation of chemical bonds or bridges
between the linear polymer is referred to as
CROSS-LINKING.
* It forms a three-dimensional (3D) network.
Application Of Cross-Linking
* The more recent acrylic resins are of cross-
linked variety. It improves the strength, and
decreases the solubility and water sorption.
* Acrylic teeth are highly cross-linked to
improve its resistance to solvents, crazing and
surface stresses.
* The more recent acrylic resins are of cross-
linked variety. It improves the strength, and
decreases the solubility and water sorption.
* Acrylic teeth are highly cross-linked to
improve its resistance to solvents, crazing and
surface stresses.
Requirements Of Denture Base
Materials
Materials
ADA Specification General
Requirements of the non-processed
Materials
Clear as Water
Free of Extraneous
Material
Requirements of the non-processed
Materials
Clear as Water
Free of Extraneous
Material
Specification General Requirements of
the non-processed Materials
POWDER, PLASTIC CAKE
OR PRECURED BLANK
FREE OF IMPURITIES.
SUCH AS DIRT AND LINT
the non-processed Materials
POWDER, PLASTIC CAKE
OR PRECURED BLANK
FREE OF IMPURITIES.
SUCH AS DIRT AND LINT
GENERAL REQURIMENTS
GENERAL REQURIMENTS
at 35008 | 20 24 18 19 22 17
| 250008 | 41 50 | 38 36 Fractured 35
+ + Se rE |
= | 0.60 055 0.50 064 0.50 0654 |
|
|
+
"Data supplied by Densply Imernational, York. Pa.
| 250008 | 41 50 | 38 36 Fractured 35
+ + Se rE |
= | 0.60 055 0.50 064 0.50 0654 |
|
|
+
"Data supplied by Densply Imernational, York. Pa.
Ideal Requirements Of Denture Base
Materials
Final report of the workshop on clinical requirements of
ideal denture base material
1. Physiologic compatability a
+ Nontoxic
Noncarcinogenic
Nonallergenic
+ Compatible with physiologic requirements of mucous
membranes Optimum consistency to maintain or
promote tissue health
* Not deleterious to adjacent and underlying tissues
+ Conducive to normal salivary flow
ATWOOD:JPD 1968 (20) 101-105
Materials
Final report of the workshop on clinical requirements of
ideal denture base material
1. Physiologic compatability a
+ Nontoxic
Noncarcinogenic
Nonallergenic
+ Compatible with physiologic requirements of mucous
membranes Optimum consistency to maintain or
promote tissue health
* Not deleterious to adjacent and underlying tissues
+ Conducive to normal salivary flow
ATWOOD:JPD 1968 (20) 101-105
. Acceptability to patients' senses
Acceptable to all five senses-sight, sound, smell, taste,
and touch
Able to duplicate and simulate oral tissues as nearly as
possible
Possessing wide selection of color
Possible for esthetics to be easily modified
Color stable % w
Odorless SS
Tasteless
Possessing instantaneous temperature conductivity
Light weight
Possessing sensation of natural texture
Acceptable to all five senses-sight, sound, smell, taste,
and touch
Able to duplicate and simulate oral tissues as nearly as
possible
Possessing wide selection of color
Possible for esthetics to be easily modified
Color stable % w
Odorless SS
Tasteless
Possessing instantaneous temperature conductivity
Light weight
Possessing sensation of natural texture
. Functional usefulness
+ Rigid enough so that teeth penetrate the bolus
No interference with oral functions of chewing,
swallowing, self cleansing, singing, speech, sneezing,
breathing, laughing, coughing, etc.
yy te x #
N Le)
sé I can feel L. +
+ Rigid enough so that teeth penetrate the bolus
No interference with oral functions of chewing,
swallowing, self cleansing, singing, speech, sneezing,
breathing, laughing, coughing, etc.
yy te x #
N Le)
sé I can feel L. +
4. Hygienic factors @)
+ Sterilizable
* Resistant to stain, calculus, and adherent substances
* Nonporous to microorganisms
* Low fluid absorption
* Wettable (low surface tension)
+ Easily cleaned
HYGIENICALLY CLEAN
TRSA CERTIFIED
+ Sterilizable
* Resistant to stain, calculus, and adherent substances
* Nonporous to microorganisms
* Low fluid absorption
* Wettable (low surface tension)
+ Easily cleaned
HYGIENICALLY CLEAN
TRSA CERTIFIED
5.
Durability
Not affected by oral environment-bacteria, food,
medicines, etc. Unbreakable (not brittle)
Not crazing
Dimensionally stable and statically stable
Minimal internal strain
Good bond between different base materials
Good bond between base and teeth
Not flammable
Resistant to weak acids and alkalis
Resistant to abrasion and wear
Resistant to strain
Long lasting
Durability
Not affected by oral environment-bacteria, food,
medicines, etc. Unbreakable (not brittle)
Not crazing
Dimensionally stable and statically stable
Minimal internal strain
Good bond between different base materials
Good bond between base and teeth
Not flammable
Resistant to weak acids and alkalis
Resistant to abrasion and wear
Resistant to strain
Long lasting
6. Adaptability to clinical problems
Adjustable
Easily polished
Easily repaired
Easily relined
May need more than one type of material
May use combinations of materials (soft for
tissues, hard for teeth) Choice of hardness or
softness (various materials for different
situations
Adjustable
Easily polished
Easily repaired
Easily relined
May need more than one type of material
May use combinations of materials (soft for
tissues, hard for teeth) Choice of hardness or
softness (various materials for different
situations
7. Cost factors
Simple to manipulate
Simple to process
Inexpensive equipment for processing Average
skill required for processing No separation
medium required Easily separated from cast
Moderate cost of fabrication
Good shelf life
Predictable properties
Simple to manipulate
Simple to process
Inexpensive equipment for processing Average
skill required for processing No separation
medium required Easily separated from cast
Moderate cost of fabrication
Good shelf life
Predictable properties
PRINCIPAL INGRIDIENTS OF DENTURE
BASE RESIN
BASE RESIN
PRINCIPAL INGREDIENTS OF ACRYLIC
DENTURE BASE RESIN
Acrylic polymer (or Copolymer) beads Monomer
Initiator Inhibitor
Pigments Accelerator
Dyes Plasticizer
Opacifiers Plasticizer Cross-linking agent
Dyed organic fibers
Inorganic particles
CRAIG RESTORATIVE DENTAL MATERIAL
DENTURE BASE RESIN
Acrylic polymer (or Copolymer) beads Monomer
Initiator Inhibitor
Pigments Accelerator
Dyes Plasticizer
Opacifiers Plasticizer Cross-linking agent
Dyed organic fibers
Inorganic particles
CRAIG RESTORATIVE DENTAL MATERIAL
Acrylic Resins used In Dentistry
« Derivatives of Ethylene and contains a vinyl
group in their structural formula.
* Acrylic resin used in dentistry are the esters of
— Acrylic acid, CH2= CHCOOH
— Methacrylic acid, CH2= C(CH3)COOH
« Derivatives of Ethylene and contains a vinyl
group in their structural formula.
* Acrylic resin used in dentistry are the esters of
— Acrylic acid, CH2= CHCOOH
— Methacrylic acid, CH2= C(CH3)COOH
DENTURE BASE RESINS
HEAT ACTIVATED DENTURE BASE RESINS
* Most widely used resins for the fabrication of complete
dentures.
+ Available as:-
— Powder and liquid
* Powder may be transparent or tooth colored or pink colored
(to stimulate the gum, some even contain red fibers to
duplicate blood vessels).
* Monomer is supplied in tightly sealed amber colored bottles
(to prevent premature polymerization by light or ultraviolet
radiation on storage).
HEAT ACTIVATED DENTURE BASE RESINS
* Most widely used resins for the fabrication of complete
dentures.
+ Available as:-
— Powder and liquid
* Powder may be transparent or tooth colored or pink colored
(to stimulate the gum, some even contain red fibers to
duplicate blood vessels).
* Monomer is supplied in tightly sealed amber colored bottles
(to prevent premature polymerization by light or ultraviolet
radiation on storage).
* Commercial Names:-
— Stellon (DPI)
— Lucitone (Bayer)
— Travellon (Dentsply)
— Stellon (DPI)
— Lucitone (Bayer)
— Travellon (Dentsply)
Composition
POWDER
Poly (methyl methacrylate)
Ethyl or butyl Methacylate (5 %)
Benzoyl Peroxide
Compounds of Mercuric sulfide, cadmium
sulfide, etc.
Zinc or titanium oxide
Dibutyl phthalate
Inorganic fillers like glass fibers, zirconium
silicate, alumina, etc.
Dyes synthetic nylon or acrylic fibers
Major component
Copolymers — improved properties
Initiator
Dyes
Opacifiers
Plasticizer
Improves physical properties like stiffness,
etc.
To simulate small capillaries
POWDER
Poly (methyl methacrylate)
Ethyl or butyl Methacylate (5 %)
Benzoyl Peroxide
Compounds of Mercuric sulfide, cadmium
sulfide, etc.
Zinc or titanium oxide
Dibutyl phthalate
Inorganic fillers like glass fibers, zirconium
silicate, alumina, etc.
Dyes synthetic nylon or acrylic fibers
Major component
Copolymers — improved properties
Initiator
Dyes
Opacifiers
Plasticizer
Improves physical properties like stiffness,
etc.
To simulate small capillaries
Composition
LIQUID
Methyl methacrylate Plasticizes the polymer
Dibutyl phthalate Plasticizer
Glycol Dimethacrylate Cross-Linking agent (reduces Crazing)
Hydroquinone (0.006%) Inhibitor — prevents premature
polymerization
LIQUID
Methyl methacrylate Plasticizes the polymer
Dibutyl phthalate Plasticizer
Glycol Dimethacrylate Cross-Linking agent (reduces Crazing)
Hydroquinone (0.006%) Inhibitor — prevents premature
polymerization
Chemical Basis
ad E SS A A del 5
- a be hr 20 fs dr \
2° 0 Rao EEO "Pr. D'y 24
POLYMER POWDER OF ACRYLIC DENTURE BASE MATERIAL
- a be hr 20 fs dr \
2° 0 Rao EEO "Pr. D'y 24
POLYMER POWDER OF ACRYLIC DENTURE BASE MATERIAL
TECHNIQUE
+ Primary impressions
» Secondary impressions
> Jaw relations
+ Try in stage
> Acrylization
— Flasking
— Dewaxing
— Packing- under pressure
— Curing
+ Primary impressions
» Secondary impressions
> Jaw relations
+ Try in stage
> Acrylization
— Flasking
— Dewaxing
— Packing- under pressure
— Curing
Flasking
* The Art of Investing in a Flask”
- GPT
« Flask
“a metal case or tube used in investing
procedure”
- metal
- brass
- 3or4 parts
* The Art of Investing in a Flask”
- GPT
« Flask
“a metal case or tube used in investing
procedure”
- metal
- brass
- 3or4 parts
3 PART FLASK
4 PART FLASK
PRESSURE CLAMP
FLASKING
N
3 POUR 4 POUR
TECHNIQUE TECHNIQUE
N
3 POUR 4 POUR
TECHNIQUE TECHNIQUE
COMPRESSION MOLDING TECHNIQUE
> Periphery of flask should be in
level with the rim of the flask
> Occlusal plane — parallel to the
base of the flask
> Periphery of flask should be in
level with the rim of the flask
> Occlusal plane — parallel to the
base of the flask
Tilting of the casts
Retromolar pads and tuberosity
should be protected
Checking the seating of flask
members
Distance from top lid — 6 mm
Retromolar pads and tuberosity
should be protected
Checking the seating of flask
members
Distance from top lid — 6 mm
Paint on separating
media like cellulose
lacquers, solution
containing alginate
compounds, calcium
oleate ,soaps, sodium
silicate, starches were
introduced..... Tin foil
substitutes.
Most popular... water
soluble alginate solution
Produce thin, relatively
insoluble calcium
alginate films.....
media like cellulose
lacquers, solution
containing alginate
compounds, calcium
oleate ,soaps, sodium
silicate, starches were
introduced..... Tin foil
substitutes.
Most popular... water
soluble alginate solution
Produce thin, relatively
insoluble calcium
alginate films.....
Sodium Alginate Solution
° Water soluble.
* Reacts with the calcium of plaster or stone to
form a film of insoluble calcium alginate.
* Composition
—2% sodium alginate in water
— Glycerine
— Alcohol
— Sodium phosphate
— Preservatives
° Water soluble.
* Reacts with the calcium of plaster or stone to
form a film of insoluble calcium alginate.
* Composition
—2% sodium alginate in water
— Glycerine
— Alcohol
— Sodium phosphate
— Preservatives
Sodium Alginate Solution
° Application
— Applied using brush, coating only the plaster
surfaces.
— One or two coats are applied.
° Application
— Applied using brush, coating only the plaster
surfaces.
— One or two coats are applied.
Sodium Alginate Solution
* Precautions to be taken
— Waxes or oils remaining on the mold surface will
interfere with the action of the separating
medium.
— Mold should not be warm, not hot. Continuity of
the film will break if the mold is steaming hot.
— Avoid coating on teeth.
* Precautions to be taken
— Waxes or oils remaining on the mold surface will
interfere with the action of the separating
medium.
— Mold should not be warm, not hot. Continuity of
the film will break if the mold is steaming hot.
— Avoid coating on teeth.
« Second mix is mixed
* Lid is closed
« Flask is clamped
* Lid is closed
« Flask is clamped
Polymer — Monomer Interaction
« Sandy, stringy, dough like, rubbery or elastic,
stiff
* During sandy stage, little or no interaction
occurs on a molecular level. Polymer beads
remain unaltered.
* Later, mixture enters stringy stage. Monomer
attacks the surfaces of individual polymer
beads. Stage characterized by stringiness.
« Sandy, stringy, dough like, rubbery or elastic,
stiff
* During sandy stage, little or no interaction
occurs on a molecular level. Polymer beads
remain unaltered.
* Later, mixture enters stringy stage. Monomer
attacks the surfaces of individual polymer
beads. Stage characterized by stringiness.
Polymer — Monomer Interaction
+ Subsequently the mass enters a dough like
stage. On molecular level increased number of
polymer chains are formed. Clinically the mass
becomes as a pliable dough. It is no longer
tacky
* This stage is ideal for compression molding.
* Hence material is inserted into mold cavity
during dough like stage.
+ Subsequently the mass enters a dough like
stage. On molecular level increased number of
polymer chains are formed. Clinically the mass
becomes as a pliable dough. It is no longer
tacky
* This stage is ideal for compression molding.
* Hence material is inserted into mold cavity
during dough like stage.
Following dough like stage, the mixture enters
rubbery or elastic stage. Monomer is
dissipated by evaporation and by further
penetration into remaining polymer beads. In
clinical use the mass rebounds when
compressed or stretched.
Upon standing for an extended period, the
mixture becomes stiff. This may be attributed
to the evaporation of free monomer. From
clinical point, the mixture appears very dry
and resistant to mechanical deformation
rubbery or elastic stage. Monomer is
dissipated by evaporation and by further
penetration into remaining polymer beads. In
clinical use the mass rebounds when
compressed or stretched.
Upon standing for an extended period, the
mixture becomes stiff. This may be attributed
to the evaporation of free monomer. From
clinical point, the mixture appears very dry
and resistant to mechanical deformation
DOUGH FORMING TIME
* The time required for the resin mixture to
reach a dough like stage is termed the dough
forming time.
* In clinical use, the majority of resin reach a
dough like consistency in less than 10 min.
* The time required for the resin mixture to
reach a dough like stage is termed the dough
forming time.
* In clinical use, the majority of resin reach a
dough like consistency in less than 10 min.
PACKING
* Placement and adaptation of denture
base material within the mold cavity is
termed packing.
Over packing- leads to excessive |
eee and malposition of prosthetic
teet
Under packing- leads to noticeable
denture base porosity
* Trial packing is done to ensure proper
packing of resin mass in the mold.
« After the final closure of the flasks,
they should remain at room
temperature for 30- 60 min. it is called
bench curing
* Placement and adaptation of denture
base material within the mold cavity is
termed packing.
Over packing- leads to excessive |
eee and malposition of prosthetic
teet
Under packing- leads to noticeable
denture base porosity
* Trial packing is done to ensure proper
packing of resin mass in the mold.
« After the final closure of the flasks,
they should remain at room
temperature for 30- 60 min. it is called
bench curing
Bench curing
* It permits equalization of
pressure throughout the mold
Allows more time for uniform
dispersion of monomer
throughout the mass of dough
If resin teeth are used, it
provides a longer exposure of
resin teeth to the monomer
producing a better bond of the
teeth with the base material
* It permits equalization of
pressure throughout the mold
Allows more time for uniform
dispersion of monomer
throughout the mass of dough
If resin teeth are used, it
provides a longer exposure of
resin teeth to the monomer
producing a better bond of the
teeth with the base material
POLYMERIZATION PROCEDURE / CURING
* When heated above 60 °C, molecules of benzoyl
peroxide decompose to yield free radicals.
* Each free radicals, rapidly reacts with an available
monomer molecule to initiate polymerization.
« Heat is required to cause decomposition of
benzoyl peroxide. Therefore heat is termed as
activator.
* Decomposition of benzoyl peroxide molecule
yields free radicals that are responsible for
initiation of chain growth. Hence it is termed as
initiator
* When heated above 60 °C, molecules of benzoyl
peroxide decompose to yield free radicals.
* Each free radicals, rapidly reacts with an available
monomer molecule to initiate polymerization.
« Heat is required to cause decomposition of
benzoyl peroxide. Therefore heat is termed as
activator.
* Decomposition of benzoyl peroxide molecule
yields free radicals that are responsible for
initiation of chain growth. Hence it is termed as
initiator
Temperature rise
Because resin and dental stone are relatively
poor thermal conductors, the heat of reaction
cannot be dissipated. Therefore the
temperature of resin rises well above the
temperature of investing stone and
surrounding water.
It should be noted that temperature of resin
not allowed to exceed the boiling point of the
monomer (100.8°C) — which produces
significant effects on the physical
characteristics of the processed resin.
Because resin and dental stone are relatively
poor thermal conductors, the heat of reaction
cannot be dissipated. Therefore the
temperature of resin rises well above the
temperature of investing stone and
surrounding water.
It should be noted that temperature of resin
not allowed to exceed the boiling point of the
monomer (100.8°C) — which produces
significant effects on the physical
characteristics of the processed resin.
Curing cycle
* Following curing cycle have been quite
successful
— Processing in a constant temperature water bath
at 74°C for 8 hours or longer with no terminal
boil.
— Processing in a 74°C water bath for 8 hours and
then increasing the temperature to 100°C for 1
hour.
— Processing resin at 74°C for approximately 2
hours and increasing the temperature of water
bath to 100°C for 1 hour.
* Following curing cycle have been quite
successful
— Processing in a constant temperature water bath
at 74°C for 8 hours or longer with no terminal
boil.
— Processing in a 74°C water bath for 8 hours and
then increasing the temperature to 100°C for 1
hour.
— Processing resin at 74°C for approximately 2
hours and increasing the temperature of water
bath to 100°C for 1 hour.
Polymer — Monomer Ratio
Polymerization of MMA to PMMA yields 21%
decrease in the volume of material, which would
create difficulties in denture base fabrication and
clinical use.
To minimize dimensional changes, Resin
manufacturers prepolymerize a significant
fraction of the denture base resin.
The accepted polymer to monomer ratio is 3:1 by
volume.
Using this ratio the volumetric shrinkage is
limited to 6% and 0.5% linear shrinkage.
Polymerization of MMA to PMMA yields 21%
decrease in the volume of material, which would
create difficulties in denture base fabrication and
clinical use.
To minimize dimensional changes, Resin
manufacturers prepolymerize a significant
fraction of the denture base resin.
The accepted polymer to monomer ratio is 3:1 by
volume.
Using this ratio the volumetric shrinkage is
limited to 6% and 0.5% linear shrinkage.
Polymer — Monomer Ratio
If too much monomer is use:-
Greater curing or polymerization shrinkage Not all the polymer bead will be wetted by
monomer and the cured acrylic will be
granular.
More time is needed to reach the packing Dough will be difficult to manage and it
consistency may not fuse into a continuous unit of
plastic during processing
Porosity may occur in denture
If too much monomer is use:-
Greater curing or polymerization shrinkage Not all the polymer bead will be wetted by
monomer and the cured acrylic will be
granular.
More time is needed to reach the packing Dough will be difficult to manage and it
consistency may not fuse into a continuous unit of
plastic during processing
Porosity may occur in denture
POLYMERIZATION VIA MICROWAVE
ENERGY
* First reported by Kimura et. al
* This technique employs a
specially formulated resin and
anon metallic flasks. FRP Flask
[ Fiber Reinforced Plastic flasks]
ENERGY
* First reported by Kimura et. al
* This technique employs a
specially formulated resin and
anon metallic flasks. FRP Flask
[ Fiber Reinforced Plastic flasks]
Advantages:
Cleaner and faster polymerization.
3 minutes
Minimal color changes
Less fracture of artificial teeth and
resin bases
Superior denture base adaptability
Cleaner and faster polymerization.
3 minutes
Minimal color changes
Less fracture of artificial teeth and
resin bases
Superior denture base adaptability
+ No noticeable difference
* Trade name
— Keystone Diamond D
+ Disadvantages
Y Flasks are expensive and have tendencyto
break down after processing several dentures.
Y The polycarbon bolts tend to break if
tightened too firmly.
Bernard Levin et al [ JPD 1989;61: 381-383]
* Trade name
— Keystone Diamond D
+ Disadvantages
Y Flasks are expensive and have tendencyto
break down after processing several dentures.
Y The polycarbon bolts tend to break if
tightened too firmly.
Bernard Levin et al [ JPD 1989;61: 381-383]
Injection molded
polymers
* In mid 1970's, Ivoclar introduced
this system.
* These are made of Nylon or
Polycarbonate.
* It has to be heated and injected
into a mold
The SR-Ivocap system uses specialized flasks and
clamping presses to keep the molds under a
constant pressure of 3000 lbs
polymers
* In mid 1970's, Ivoclar introduced
this system.
* These are made of Nylon or
Polycarbonate.
* It has to be heated and injected
into a mold
The SR-Ivocap system uses specialized flasks and
clamping presses to keep the molds under a
constant pressure of 3000 lbs
Injection molded polymers
* Flask is then placed into water bath
for polymerization as the material
polymerizes addition resin is
introduced into the mold cavity. This
process offsets the effects of
polymerization shrinkage.
* Equipment is expensive.
The SR-Ivocap system uses specialized flasks and
clamping presses to keep the molds under a
constant pressure of 3000 lbs
* Flask is then placed into water bath
for polymerization as the material
polymerizes addition resin is
introduced into the mold cavity. This
process offsets the effects of
polymerization shrinkage.
* Equipment is expensive.
The SR-Ivocap system uses specialized flasks and
clamping presses to keep the molds under a
constant pressure of 3000 lbs
Injection molded polymers
+ Advantages
— Dimensional Accuracy
— No increase in vertical dimension.
— Homogenous denture base
— Low free monomer content
— Good impact strength
* Disadvantages
— High cost of equipment
— Difficult mold design
— Less craze resistant
— Special flask is required.
+ Advantages
— Dimensional Accuracy
— No increase in vertical dimension.
— Homogenous denture base
— Low free monomer content
— Good impact strength
* Disadvantages
— High cost of equipment
— Difficult mold design
— Less craze resistant
— Special flask is required.
Technique
Fig. 3: Injection molding flask
Figs AA and D: Bloctre cartridge tumace
Fig. 3: Injection molding flask
Figs AA and D: Bloctre cartridge tumace
Fig. SA: Manual compression unit
Fig. &: Mandiular complete Patio dontare win sprue former
Fig. SB: Prossuro compression unit
Fig. 9: Finishes and polished flaxbie mandibular
completo derture
Fig. &: Mandiular complete Patio dontare win sprue former
Fig. SB: Prossuro compression unit
Fig. 9: Finishes and polished flaxbie mandibular
completo derture
Chemically Activated Denture Base
Resins
+ Does not require thermal energy.
+ Hence often referred to as cold curing, self
curing or autopolymerizing resins.
DPI-RR Cold Cure
Resins
+ Does not require thermal energy.
+ Hence often referred to as cold curing, self
curing or autopolymerizing resins.
DPI-RR Cold Cure
Chemically Activated Denture Base
Resins
* Chemical activation is accomplished through
the addition of a tertiary amine such as
dimethyl- Para- toluidine to the liquid.
* Upon mixing, the tertiary amine causes
decomposition of benzoyl peroxide.
Consequently, free radicals are produced and
polymerization is initiated.
Resins
* Chemical activation is accomplished through
the addition of a tertiary amine such as
dimethyl- Para- toluidine to the liquid.
* Upon mixing, the tertiary amine causes
decomposition of benzoyl peroxide.
Consequently, free radicals are produced and
polymerization is initiated.
Composition
POWDER
Poly (methyl methacrylate) and
other co-polymer(5 %)
Benzoyl Peroxide
Compounds of Mercuric sulfide,
cadmium sulfide, etc.
Zinc or titanium oxide
Dibuty! phthalate
Dyes organic fillers and inorganic
particles like glass bead fibers or
beads.
Dissolves the monomer to form
dough
Initiator
Dyes
Opacifiers
Plasticizer
Esthetics
POWDER
Poly (methyl methacrylate) and
other co-polymer(5 %)
Benzoyl Peroxide
Compounds of Mercuric sulfide,
cadmium sulfide, etc.
Zinc or titanium oxide
Dibuty! phthalate
Dyes organic fillers and inorganic
particles like glass bead fibers or
beads.
Dissolves the monomer to form
dough
Initiator
Dyes
Opacifiers
Plasticizer
Esthetics
Composition
LIQUID
Methyl methacrylate Dissolves/Plasticizes the polymer
Dimethyl-p-toluidine Activator
Dibutyl phthalate Plasticizer
Glycol Dimethacrylate 1 to 2% Cross-Linking agent (reduces Crazing)
Hydroquinone (0.006%) Inhibitor — prevents premature
polymerization
LIQUID
Methyl methacrylate Dissolves/Plasticizes the polymer
Dimethyl-p-toluidine Activator
Dibutyl phthalate Plasticizer
Glycol Dimethacrylate 1 to 2% Cross-Linking agent (reduces Crazing)
Hydroquinone (0.006%) Inhibitor — prevents premature
polymerization
MANIPULATION OF
AUTOPOLYMERIZATION RESINS
Sprinkle on technique
Adapting technique
Fluid resin technique
Compression molding technique
AUTOPOLYMERIZATION RESINS
Sprinkle on technique
Adapting technique
Fluid resin technique
Compression molding technique
° There is greater amount of
unreacted monomer which E
creates two major difficulties.
1. It acts as plasticizer that results
in decreased transverse
strength of denture resin.
2. Residual monomer serves as a
potential tissue irritant,
thereby compromising the
biocompatibility of the
denture base.
unreacted monomer which E
creates two major difficulties.
1. It acts as plasticizer that results
in decreased transverse
strength of denture resin.
2. Residual monomer serves as a
potential tissue irritant,
thereby compromising the
biocompatibility of the
denture base.
Technical considerations a
Most often molded using compression
REFRIGERATE
technique. do not freeze
Mold preparation and resin packing are
essentially same.
Working time for self cure resin is shorter
than heat cured resins.
Refrigerating the liquid component or mixing
vessel before mixing process can prolong the
working time.
Most often molded using compression
REFRIGERATE
technique. do not freeze
Mold preparation and resin packing are
essentially same.
Working time for self cure resin is shorter
than heat cured resins.
Refrigerating the liquid component or mixing
vessel before mixing process can prolong the
working time.
Processing considerations
* Following final closure of the denture flask,
pressure must be maintained throughout
polymerization process.
¢ Initial hardening of resin occurs within 30
minutes of final closure.
« To ensure sufficient polymerization, the flask
should be held under pressure for minimum 3
hours
* Resins polymerized via chemical activation
generally display 3-5% free monomer where as
heat activated resins 0.2-0.5% free monomer.
* Following final closure of the denture flask,
pressure must be maintained throughout
polymerization process.
¢ Initial hardening of resin occurs within 30
minutes of final closure.
« To ensure sufficient polymerization, the flask
should be held under pressure for minimum 3
hours
* Resins polymerized via chemical activation
generally display 3-5% free monomer where as
heat activated resins 0.2-0.5% free monomer.
Uses
Temporary crowns and FPDs.
Construction of special tray.
For denture repair, relining and rebasing.
Making removable orthodontic appliances.
For adding a post dam to an adjusted upper
denture.
For making temporary and permanent
denture bases.
Temporary crowns and FPDs.
Construction of special tray.
For denture repair, relining and rebasing.
Making removable orthodontic appliances.
For adding a post dam to an adjusted upper
denture.
For making temporary and permanent
denture bases.
FLUID RESIN TECHNIQUE
Special resin is available.
Chemical composition is similar to polymethyl
methacrylate materials.
Principal difference is they have high
molecular weight powder particles that are
much smaller and when they are mixed with
monomer, the resulting mix is very fluid.
Significantly lower power: liquid ratio ranges
from 2:1 to 2.5:1.
Special resin is available.
Chemical composition is similar to polymethyl
methacrylate materials.
Principal difference is they have high
molecular weight powder particles that are
much smaller and when they are mixed with
monomer, the resulting mix is very fluid.
Significantly lower power: liquid ratio ranges
from 2:1 to 2.5:1.
Method of Flasking and Curing
+ Agar hydrocolloid is used for the mold
preparation in place of the usual gypsum.
* Fluid mix is quickly poured into the mold and
allowed to polymerize under pressure at 0.14
MPa.
+ Agar hydrocolloid is used for the mold
preparation in place of the usual gypsum.
* Fluid mix is quickly poured into the mold and
allowed to polymerize under pressure at 0.14
MPa.
Fluid Resin Technique
Employs a pourable chemically activated
resin
Advantages
Improved adaptation to underlying soft
tissues.
Decreased damage to prosthetic teeth and
denture base during deflasking.
Reduced material costs.
Simplification of flasking, deflasking, finishing
procedure
Walter Shepard [ JPD 1968;19: 562-564]
Employs a pourable chemically activated
resin
Advantages
Improved adaptation to underlying soft
tissues.
Decreased damage to prosthetic teeth and
denture base during deflasking.
Reduced material costs.
Simplification of flasking, deflasking, finishing
procedure
Walter Shepard [ JPD 1968;19: 562-564]
Fluid Resin Technique
Disadvantages
« Noticeable shifting of prosthetic teeth
during processing
« Air entrapment
* Poor bonding between denture base and
acrylic teeth
* Technique sensitivity
Walter Shepard [ JPD 1968;19: 562-564]
Disadvantages
« Noticeable shifting of prosthetic teeth
during processing
« Air entrapment
* Poor bonding between denture base and
acrylic teeth
* Technique sensitivity
Walter Shepard [ JPD 1968;19: 562-564]
Fluid denture resin processing in a rigid mold
Koblitz FF et al described a fluid resin processing
technique using rigid, modified gypsum
investment as replacement for hydrocolloid
investment.
Advantages
Method requires no specialized equipment such
as metal flasks or hydrocolloid conditioning
apparatus
The technique eliminates the time consuming
step of sorting and replacing artificial teeth in as
hydrocolloid mold.
[JPD 1973; 30; 339-345 ]
Koblitz FF et al described a fluid resin processing
technique using rigid, modified gypsum
investment as replacement for hydrocolloid
investment.
Advantages
Method requires no specialized equipment such
as metal flasks or hydrocolloid conditioning
apparatus
The technique eliminates the time consuming
step of sorting and replacing artificial teeth in as
hydrocolloid mold.
[JPD 1973; 30; 339-345 ]
St Er nad
NN AK )
NN AK )
Self Cured
Heat is not necessary for polymerization
Porosity is greater
Has lower average molecular weight (not
Strong)
Higher residual monomer content
Rheological properties
- Shows greater distortion
- More initial deformation
- Increased creep and slow recovery
Poor color stability
Easy to flask
Heat Cured
Heat is necessary
Porosity is less
Higher molecular weight
Lower residual monomer content
- Shows less distortion
- Less initial deformation
- Less creep and quicker recovery
Color stability is good
Difficult to deflask
Increased rate of monomer diffusion at
higher temperature.
120
Heat is not necessary for polymerization
Porosity is greater
Has lower average molecular weight (not
Strong)
Higher residual monomer content
Rheological properties
- Shows greater distortion
- More initial deformation
- Increased creep and slow recovery
Poor color stability
Easy to flask
Heat Cured
Heat is necessary
Porosity is less
Higher molecular weight
Lower residual monomer content
- Shows less distortion
- Less initial deformation
- Less creep and quicker recovery
Color stability is good
Difficult to deflask
Increased rate of monomer diffusion at
higher temperature.
120
Light Activated Denture Base Resins
This material has been
described as a composite
having a matrix of urethane
dimethacrylate and microfine
silica
Visible light is the activator
Camphoroquinone serves as
the initiator for
polymerization
Supplied in sheets and ira
forms and is packed in light
proof pouches.
This material has been
described as a composite
having a matrix of urethane
dimethacrylate and microfine
silica
Visible light is the activator
Camphoroquinone serves as
the initiator for
polymerization
Supplied in sheets and ira
forms and is packed in light
proof pouches.
Light Activated Denture Base Resins
+ Can be used as repair material and as custom
tray material.
¢ Single component denture base is supplied as
sheet and rope form in light proof pouches.
+ Can be used as repair material and as custom
tray material.
¢ Single component denture base is supplied as
sheet and rope form in light proof pouches.
* Technique
— Teeth are arranged, and the denture base is molded on an
accurate cast.
— Subsequently the denture base is exposed to high intensity
visible light source for an appropriate period
— Following polymerization, the denture is removed from the
cast, finished and polished in a conventional manner.
— Teeth are arranged, and the denture base is molded on an
accurate cast.
— Subsequently the denture base is exposed to high intensity
visible light source for an appropriate period
— Following polymerization, the denture is removed from the
cast, finished and polished in a conventional manner.
Properties Of Denture Base Resins
+ METHYL METHACRYLATE
® Methyl methacrylate is a transparent liquid at room
temp.
e Physical properties
-Molecular weight = 100
-Melting point = - 48 C
-Boiling point = 100.8 C
-Density = 0.945g/ml at 20 C
-Heat of polymerization=12.9 Kcal/mol
+ METHYL METHACRYLATE
® Methyl methacrylate is a transparent liquid at room
temp.
e Physical properties
-Molecular weight = 100
-Melting point = - 48 C
-Boiling point = 100.8 C
-Density = 0.945g/ml at 20 C
-Heat of polymerization=12.9 Kcal/mol
POLYMETHYL METHACRYLATE
* Transparent resin, transmits light in UV range
to a wavelength of 250 nm.
+ Hard resin knoop hardness no of 18 to 20.
* Tensile strength is 60 MPa
* Density is 1.19 g/cm cube.
°e Modulus of elasticity 2.4 GPa(2400 MPa)
* Transparent resin, transmits light in UV range
to a wavelength of 250 nm.
+ Hard resin knoop hardness no of 18 to 20.
* Tensile strength is 60 MPa
* Density is 1.19 g/cm cube.
°e Modulus of elasticity 2.4 GPa(2400 MPa)
POLYMETHYL METHACRYLATE
It is chemically stable and softens at 125°C
It can be molded as a thermoplastic material
between 125°C and 200°C.
Depolarization takes place at approx. 450°C.
Absorbs water by imbibition
Non crystalline structure possess high internal
energy.
It is chemically stable and softens at 125°C
It can be molded as a thermoplastic material
between 125°C and 200°C.
Depolarization takes place at approx. 450°C.
Absorbs water by imbibition
Non crystalline structure possess high internal
energy.
Strength
* Resins are typically low in strength, however they
have adequate compressive and tensile strength
for complete or partial denture applications.
+ Compressive strength- 75 Mpa
* Tensile strength- 52 Mpa
Affected by:-
* Composition of the resin
e Technique of processing
« Degree of polymerization
« Water sorption
e Subsequent environment of the denture
* Resins are typically low in strength, however they
have adequate compressive and tensile strength
for complete or partial denture applications.
+ Compressive strength- 75 Mpa
* Tensile strength- 52 Mpa
Affected by:-
* Composition of the resin
e Technique of processing
« Degree of polymerization
« Water sorption
e Subsequent environment of the denture
Hardness
* Resins have low hardness. They can be easily
scratched and abraded.
+ Heat cured resin- 18-20 KHN
° Self cured resin- 16-18 KHN
* Resins have low hardness. They can be easily
scratched and abraded.
+ Heat cured resin- 18-20 KHN
° Self cured resin- 16-18 KHN
Modulus of elasticity
* Resins have sufficient stiffness [ 2400MPa] for
use in complete and partial dentures.
Impact Strength
* It is the measure of energy absorbed by a
material when it is broken by a sudden blow.
* Addition of plasticizers increase the impact
strength.
* Resins have sufficient stiffness [ 2400MPa] for
use in complete and partial dentures.
Impact Strength
* It is the measure of energy absorbed by a
material when it is broken by a sudden blow.
* Addition of plasticizers increase the impact
strength.
WODkQrourmww ASIA “SEPAN POLI 104
Processing
Condition
100° €, 20 min
10 min in light chamber
H°G 9h
45°C, 0,14 MPa
3 min, 500 W
‘Adupeed with permission frown Sanit LT, Powers JM, Ladd De dnt J Prost! $315, 1992.
130
Processing
Condition
100° €, 20 min
10 min in light chamber
H°G 9h
45°C, 0,14 MPa
3 min, 500 W
‘Adupeed with permission frown Sanit LT, Powers JM, Ladd De dnt J Prost! $315, 1992.
130
Polymerization shrinkage
+ When MMA monomer is polymerized to form PMMA..
Results in 21% volumetric shrinkage.
+ To reduce this high % of shrinkage... polymer powder is
supplied in prepolymerized beads form which accounts
for only 7% of volumetric shrinkage.
* Distributed uniformly to all surfaces, hence the
adaptation of denture bases to underlying soft tissues
is not significantly affected.
Processing shrinkage
Due to stresses induced during processing
* 0.26% for self cure resin
* 0.53% for heat activated resin
+ When MMA monomer is polymerized to form PMMA..
Results in 21% volumetric shrinkage.
+ To reduce this high % of shrinkage... polymer powder is
supplied in prepolymerized beads form which accounts
for only 7% of volumetric shrinkage.
* Distributed uniformly to all surfaces, hence the
adaptation of denture bases to underlying soft tissues
is not significantly affected.
Processing shrinkage
Due to stresses induced during processing
* 0.26% for self cure resin
* 0.53% for heat activated resin
Material
Shrinkage (%)
Conventional acrylic
High impact acrylic
Vinyl acrylic
Rapid heat-cured acrylic
Pour type of acrylic
0.43
0.12
0.33
0.97
0.48
Adapted from Stafford GD, Bates JE Huggett R, Handley
RW: J Dent 8:292, 1980,
Shrinkage (%)
Conventional acrylic
High impact acrylic
Vinyl acrylic
Rapid heat-cured acrylic
Pour type of acrylic
0.43
0.12
0.33
0.97
0.48
Adapted from Stafford GD, Bates JE Huggett R, Handley
RW: J Dent 8:292, 1980,
Denture Warpage
+ It is the deformity or change of shape of the
denture which affect the fit of the denture.
+ Stresses incorporated during processing.
Figure 25.30: Denture warpage has resulted in a space
between the palatal surface and the cast Obviously this would
affect the fit.
+ It is the deformity or change of shape of the
denture which affect the fit of the denture.
+ Stresses incorporated during processing.
Figure 25.30: Denture warpage has resulted in a space
between the palatal surface and the cast Obviously this would
affect the fit.
Denture Warpage
+ Caused by:-
* Stress causes by curing shrinkage or uneven or
rapid cooling.
* Packing of resin in rubbery stage.
+ Improper flasking.
* During polishing, a rise in temperature occurs.
+ Caused by:-
* Stress causes by curing shrinkage or uneven or
rapid cooling.
* Packing of resin in rubbery stage.
+ Improper flasking.
* During polishing, a rise in temperature occurs.
Denture Warpage
+ Caused by:-
* Immersion of the denture in hot water.
* Recuring of the denture after addition of relining
material, etc.
+ Caused by:-
* Immersion of the denture in hot water.
* Recuring of the denture after addition of relining
material, etc.
Porosity
+ May compromise physical, aesthetic and
hygienic properties of processed dentures.
+ May compromise physical, aesthetic and
hygienic properties of processed dentures.
Porosity
Internal Porosity:
e Is in form of voids or bubbles within the mass
of processed resin. It is confined to thick
portions of denture base.
* Results from vaporization of unreacted
monomer and low molecular wt. polymers,
Internal Porosity:
e Is in form of voids or bubbles within the mass
of processed resin. It is confined to thick
portions of denture base.
* Results from vaporization of unreacted
monomer and low molecular wt. polymers,
Porosity
External Porosity:
* Inadequate mixing of powder liquid
components.
* Inhomogeneity of resin mass
¢ Inadequate pressure or insufficient material
* Air inclusions incorporate
procedures.
O See porn ton
of insufficient pressure during curing,
External Porosity:
* Inadequate mixing of powder liquid
components.
* Inhomogeneity of resin mass
¢ Inadequate pressure or insufficient material
* Air inclusions incorporate
procedures.
O See porn ton
of insufficient pressure during curing,
Water Sorption
e Absorption is primarily by diffusion
mechanism.
+ Water molecules occupy positions between
polymer chains forcing the polymer chains
apart.
° The introduction of water molecules in the
polymerized mass produces two important
effects
* Acts as plasticizers
“It causes slight expansion of polymerized mass
==
e Absorption is primarily by diffusion
mechanism.
+ Water molecules occupy positions between
polymer chains forcing the polymer chains
apart.
° The introduction of water molecules in the
polymerized mass produces two important
effects
* Acts as plasticizers
“It causes slight expansion of polymerized mass
==
Water Sorption
PMMA exhibits a water sorption value of
0.69mg/cm?
Fortunately these changes are relatively
minor and do not exert significant effects
on the fit or function of processed bases.
PMMA exhibits a water sorption value of
0.69mg/cm?
Fortunately these changes are relatively
minor and do not exert significant effects
on the fit or function of processed bases.
Crazing
Is formation of surface cracks on
denture base resin.
Due to
-Stress relaxation
-Solvent action e.g. Ethyl
alcohol
Crazing in a transparent resin
imparts a hazy or foggy
appearance, k
These surface cracks predispose
a denture resin to fracture.
Is formation of surface cracks on
denture base resin.
Due to
-Stress relaxation
-Solvent action e.g. Ethyl
alcohol
Crazing in a transparent resin
imparts a hazy or foggy
appearance, k
These surface cracks predispose
a denture resin to fracture.
Plaque Adhesion
* An invitro study done on the adhesion and
penetration of C. Albicans proved that
adhesion of C. Albicans occur, but they cant
penetrate the Denture Base Resin.
A COMPARATIVE IN-VITRO STUDY ON THE ADHERENCE AND
PENETRATION OF C. ALBICANS TO THREE DIFFERENT RESIN DENTURE
BASE SURFACE -Dr. Divyang Patel
* An invitro study done on the adhesion and
penetration of C. Albicans proved that
adhesion of C. Albicans occur, but they cant
penetrate the Denture Base Resin.
A COMPARATIVE IN-VITRO STUDY ON THE ADHERENCE AND
PENETRATION OF C. ALBICANS TO THREE DIFFERENT RESIN DENTURE
BASE SURFACE -Dr. Divyang Patel
Other Microorganisms
* Streptococcus Oralis, Bacteroides gingivalis, B.
Intermedius And S. Sanguis.
* It was found, they adhere to rougher surface
than those that are highly polished.
* Streptococcus Oralis, Bacteroides gingivalis, B.
Intermedius And S. Sanguis.
* It was found, they adhere to rougher surface
than those that are highly polished.
Solution for Plaque Adhesion
° Chlorhexidine apparently can bind to acrylic
surfaces for atleast 2 weeks.
* Treating acrylic with Nystatin, followed by
drying, produced similar results.
° Chlorhexidine apparently can bind to acrylic
surfaces for atleast 2 weeks.
* Treating acrylic with Nystatin, followed by
drying, produced similar results.
Resistance to Acids, Bases And Organic
Solvents
+ Weak acids or bases = Excellent
* Quiet resistant to Organic Solvents
e Soluble in aromatic hydrocarbons, ketones and
esters.
* Alcohol will cause crazing in Denture plastic.
* Incorporating ethylene glycol dimethacrylate as a
cross linking agents significantly improves solvent
resistance.
Solvents
+ Weak acids or bases = Excellent
* Quiet resistant to Organic Solvents
e Soluble in aromatic hydrocarbons, ketones and
esters.
* Alcohol will cause crazing in Denture plastic.
* Incorporating ethylene glycol dimethacrylate as a
cross linking agents significantly improves solvent
resistance.
DENTURE CLEANSER
* Most immersion denture cleansers are
effective in the removal of mucin, stains, and
loosely attached food debris.
« A solution consisting of 1 tsp of a hypochlorite
such as Clorox, and 2 tsp of calgon in half glass
has been recommended for occassional
overnight immersion of plastic dentures.
* Most immersion denture cleansers are
effective in the removal of mucin, stains, and
loosely attached food debris.
« A solution consisting of 1 tsp of a hypochlorite
such as Clorox, and 2 tsp of calgon in half glass
has been recommended for occassional
overnight immersion of plastic dentures.
DENTURE CLEANSER
80
60
E 40
20
ms —
9 Tooth- | Denture | Exp. Soap Water
paste cleansers paste and
water
Fig. 21-15 Wear of denture base acrylic in various
media, as illustrated by a histogram showing loss of
thickness after 60,000 stokes
(Adapted from Heath JR, Davenport JC, Jones PA: J Oral Re-
habil 10:159, 1983.)
80
60
E 40
20
ms —
9 Tooth- | Denture | Exp. Soap Water
paste cleansers paste and
water
Fig. 21-15 Wear of denture base acrylic in various
media, as illustrated by a histogram showing loss of
thickness after 60,000 stokes
(Adapted from Heath JR, Davenport JC, Jones PA: J Oral Re-
habil 10:159, 1983.)
Cytotoxicity of Denture Base Acrylic
Resins
[JPD 2003: 90; 190-195 ]
* Residual monomer, resulting from incomplete conversion of
monomers into polymer, has the potential to cause
— irritation,
— inflammation,
— and an allergic responses of oral mucosa.
« Clinical signs and symptoms reported include
— erythema,
— erosion of oral mucosa,
— burning sensation of mucosa and tongue.
Resins
[JPD 2003: 90; 190-195 ]
* Residual monomer, resulting from incomplete conversion of
monomers into polymer, has the potential to cause
— irritation,
— inflammation,
— and an allergic responses of oral mucosa.
« Clinical signs and symptoms reported include
— erythema,
— erosion of oral mucosa,
— burning sensation of mucosa and tongue.
Cytotoxicity of Denture Base Acrylic
Resins
[JPD 2003: 90; 190-195 ]
Effect of polymer : monomer ratio
* More monomer added to the mixture, the greater amount of
residual monomer and therefore more potential for cytotoxicity
Effect of storage time and water immersion
« Sheridan et al reported that cytotoxic effect of acrylic resins was
greater in first 24 hours after polymerization and decreased with
time.
+ Therefore it is recommended that dentist soak the resin
prosthesis in water for atleast 24 hours before placing them in
the patients mouth.
Resins
[JPD 2003: 90; 190-195 ]
Effect of polymer : monomer ratio
* More monomer added to the mixture, the greater amount of
residual monomer and therefore more potential for cytotoxicity
Effect of storage time and water immersion
« Sheridan et al reported that cytotoxic effect of acrylic resins was
greater in first 24 hours after polymerization and decreased with
time.
+ Therefore it is recommended that dentist soak the resin
prosthesis in water for atleast 24 hours before placing them in
the patients mouth.
* Effects of polymerization cycle
* Reduced amount of residual monomer when
polymerization time extended was observed.
» Auto polymerized resins exhibited higher
content of residual monomer than heat
polymerized resins.
* Reduced amount of residual monomer when
polymerization time extended was observed.
» Auto polymerized resins exhibited higher
content of residual monomer than heat
polymerized resins.
° Lamb et al observed that levels of residual
monomer were higher for specimens
polymerized at 20°C as compared with those
at 55°C.
« Therefore it is suggested that the
Autopolymerized acrylic resins should be heat
treated to decrease cytotoxic effects.
monomer were higher for specimens
polymerized at 20°C as compared with those
at 55°C.
« Therefore it is suggested that the
Autopolymerized acrylic resins should be heat
treated to decrease cytotoxic effects.
Occupational Hazard
« Plastic dough should not be manipulated
excessively with bare hands.
* The monomer is a good solvent for body oils
and may pick up dirt from the hands,
resulting in a non esthetic denture.
* Monomer may also enter blood stream
through the skin.
Restorative Dental Materials, Robert G. Craig & John
M Powers, 11" edition
« Plastic dough should not be manipulated
excessively with bare hands.
* The monomer is a good solvent for body oils
and may pick up dirt from the hands,
resulting in a non esthetic denture.
* Monomer may also enter blood stream
through the skin.
Restorative Dental Materials, Robert G. Craig & John
M Powers, 11" edition
Recent Advances
HIGH IMPACT RESISTANT ACRYLIC
* Butadiene- styrene rubber is
incorporated with copolymer of vinyl
and hydroxyethyl monomer.
* These materials are
slightly stiffer
twice the impact strength
absorbs less water
lower linear shrinkage.
But are not entirely color stable.
HIGH IMPACT RESISTANT ACRYLIC
* Butadiene- styrene rubber is
incorporated with copolymer of vinyl
and hydroxyethyl monomer.
* These materials are
slightly stiffer
twice the impact strength
absorbs less water
lower linear shrinkage.
But are not entirely color stable.
Recent Advances sae
HIGH IMPACT RESISTANT
ACRYLIC
Phase inversion resulting in
dispersion throughout the beads of
tiny islands of rubber containing
small inclusions of rubber/PMMA
graft polymer.
HIGH IMPACT RESISTANT
ACRYLIC
Phase inversion resulting in
dispersion throughout the beads of
tiny islands of rubber containing
small inclusions of rubber/PMMA
graft polymer.
Recent Advances
RAPID HEAT POLYMERIZED POLYMER
* These are hybrid acrylics which have had the
initiator formulated to allow for very rapid
polymerization without nearly as much porosity.
The flasks are placed in boiling water immediately
after being packed. The water is then brought
back to a boil for 20 min to complete the curing
cycle.
Fast, high temperature cure makes this material
stiffer than conventional acrylic processing.
* E.g. travelon
RAPID HEAT POLYMERIZED POLYMER
* These are hybrid acrylics which have had the
initiator formulated to allow for very rapid
polymerization without nearly as much porosity.
The flasks are placed in boiling water immediately
after being packed. The water is then brought
back to a boil for 20 min to complete the curing
cycle.
Fast, high temperature cure makes this material
stiffer than conventional acrylic processing.
* E.g. travelon
FIBER -REINFORCED POLYMER
* Glass, carbon/graphite, aramid and ultrahigh
molecular weight polyethylene have been used as
fiber reinforcing agents.
* Metal wires like graphite has minimal esthetic
qualities.
* Fibers are stronger than matrix polymer thus
their inclusion strengthens the composite
structure.
* The reinforcing agent can be in the form of
unidirectional, straight fiber or multidirectional
weaves.
* Glass, carbon/graphite, aramid and ultrahigh
molecular weight polyethylene have been used as
fiber reinforcing agents.
* Metal wires like graphite has minimal esthetic
qualities.
* Fibers are stronger than matrix polymer thus
their inclusion strengthens the composite
structure.
* The reinforcing agent can be in the form of
unidirectional, straight fiber or multidirectional
weaves.
Acrylic resins with improved thermal conductivity
« Thermal conductivity of PMMA is three times less
than metals.
* Thermal conductivity of denture base materials is
found to have an important effect on gustatory
sensitivity.
* Thermal conductivity of acrylic based materials
can be improved by introducing a more thermally
conducting phase within the insulating acrylic
resin matrix.
* E.g. Al,O, porcelain whiskers
JPD 1998: 20; 278-
« Thermal conductivity of PMMA is three times less
than metals.
* Thermal conductivity of denture base materials is
found to have an important effect on gustatory
sensitivity.
* Thermal conductivity of acrylic based materials
can be improved by introducing a more thermally
conducting phase within the insulating acrylic
resin matrix.
* E.g. Al,O, porcelain whiskers
JPD 1998: 20; 278-
BPS (Biofunctional Prosthetic System)
« BPS is the system designed to work with the
body in a biologically harmonious way,
maximizing function, and giving comfort and
natural appearance to the patient.
« BPS is the system designed to work with the
body in a biologically harmonious way,
maximizing function, and giving comfort and
natural appearance to the patient.
Resorbed ridges Occlussal centric tray loaded with impression
for recording initial vertical dimension
Biofunctional prosthetic system
impression trays
for recording initial vertical dimension
Biofunctional prosthetic system
impression trays
Bite registration through Gnathometer M Secondary impression-making with zinc
oxide eugenol past
Wax-up trial for the patient
oxide eugenol past
Wax-up trial for the patient
Acrylized Denture
161
161
Flexible Denture
First introduced in 1956.
Trade name:-
— Flexiplast
— Valplast
Superpolyamides, which belong to nylon
family, which inherent property of
flexibility.
Flexibility depends on the thickness
Good retention
First introduced in 1956.
Trade name:-
— Flexiplast
— Valplast
Superpolyamides, which belong to nylon
family, which inherent property of
flexibility.
Flexibility depends on the thickness
Good retention
Flexible Denture
Advantage
* Good retention
Disadvantage
* Acrylic teeth do not bond chemically
with flexible denture base.
Advantage
* Good retention
Disadvantage
* Acrylic teeth do not bond chemically
with flexible denture base.
VALPLAST
Nylon like material
Nearly unbreakable, pink colored
like gum
Can be built quite thin, can form
not only denture base but the clasp
as well.
Valplast is a flexible denture base
resin that is ideal for partial
dentures and unilateral
restorations.
Nylon like material
Nearly unbreakable, pink colored
like gum
Can be built quite thin, can form
not only denture base but the clasp
as well.
Valplast is a flexible denture base
resin that is ideal for partial
dentures and unilateral
restorations.
VALPLAST —
* The resin is a biocompatible nylon thermoplastic
,it eliminates the concern about acrylic allergies.
° Quite hygienic. It is not possible for Valplast to
absorb the remnants of food or other stains. So
there will be no odor.
* The resin is a biocompatible nylon thermoplastic
,it eliminates the concern about acrylic allergies.
° Quite hygienic. It is not possible for Valplast to
absorb the remnants of food or other stains. So
there will be no odor.
Conclusion
640 Chapter 2} MOSTHERE AMUCANONS OF POOMERS
oss 050 O64 050 064
Water 002 002 oor 001 | 00
| color | None Sight | Stight | Sth SlightModerate
“Data supplied by Demply International, York, Pa.
640 Chapter 2} MOSTHERE AMUCANONS OF POOMERS
oss 050 O64 050 064
Water 002 002 oor 001 | 00
| color | None Sight | Stight | Sth SlightModerate
“Data supplied by Demply International, York, Pa.
Conclusion
Property
“Tensile strength (MPa)
‘Compressive strength (MPa)
Elongation (%)
‘Bastic modulus (GPa)
Proportional limit (MPa)
Impact strength, Izod (kg m/cm notch)
‘Transverse deflection (mm)
At 3500 8
At 5000 y.
Chapter 21 PROSTHETIC APPUCATIONS OF POLYMERS 641
Fatigue strength (cycles at 17.2 MPa)
Recovery after indentation (%)
Dry
Wer
KHN (kg/mm?)
Dry
Wer
17
15
167
Property
“Tensile strength (MPa)
‘Compressive strength (MPa)
Elongation (%)
‘Bastic modulus (GPa)
Proportional limit (MPa)
Impact strength, Izod (kg m/cm notch)
‘Transverse deflection (mm)
At 3500 8
At 5000 y.
Chapter 21 PROSTHETIC APPUCATIONS OF POLYMERS 641
Fatigue strength (cycles at 17.2 MPa)
Recovery after indentation (%)
Dry
Wer
KHN (kg/mm?)
Dry
Wer
17
15
167
WODkQrourmww ASIA “SEPAN POLI 104
Processing
Condition
100° €, 20 min
10 min in light chamber
H°G 9h
45°C, 0,14 MPa
3 min, 500 W
‘Adupeed with permission frown Sanit LT, Powers JM, Ladd De dnt J Prost! $315, 1992.
168
Processing
Condition
100° €, 20 min
10 min in light chamber
H°G 9h
45°C, 0,14 MPa
3 min, 500 W
‘Adupeed with permission frown Sanit LT, Powers JM, Ladd De dnt J Prost! $315, 1992.
168
Material
Material Loss
(mm x 107%)
Conventional acrylic
Rubberreinforced acrylic
Vinyl acrylic
Rapid heatcured acrylic
Pour type of acrylic
595
588
499
530
6
High impact resin
Rapid heat cure
Conventional acrylic
| Four type of acrylic
2.0
30
23
15
Adapted from Stafford GD, Bates JE Hugget R, Handley
RW: J Dent 8:292, 1980,
Material Loss
(mm x 107%)
Conventional acrylic
Rubberreinforced acrylic
Vinyl acrylic
Rapid heatcured acrylic
Pour type of acrylic
595
588
499
530
6
High impact resin
Rapid heat cure
Conventional acrylic
| Four type of acrylic
2.0
30
23
15
Adapted from Stafford GD, Bates JE Hugget R, Handley
RW: J Dent 8:292, 1980,
References
Kenneth j. Anusavice ; Phillips Science of dental
material .Eleventh edition, Elsevier,2004.
Robert C. Craig John M. Powers, John C.Wataha
¡Dental materials properties and manipulation,.
Eleventh edition,2002.
Applied Dental Materials, 8' edition, John F
McCabe & Angus W. G. Walls
Rudd and morrow; dental laboratory procedures:
1986 2" edition
Vk subbarao ; notes on dental materials : 4"
edition
Kenneth j. Anusavice ; Phillips Science of dental
material .Eleventh edition, Elsevier,2004.
Robert C. Craig John M. Powers, John C.Wataha
¡Dental materials properties and manipulation,.
Eleventh edition,2002.
Applied Dental Materials, 8' edition, John F
McCabe & Angus W. G. Walls
Rudd and morrow; dental laboratory procedures:
1986 2" edition
Vk subbarao ; notes on dental materials : 4"
edition
Basic Dental Materials — John J. Manappallil,
3'd edition
Walter Shepard : fluid resin technique; JPD
1968 (19) 561-
Koblitz F.F et al: Fluid denture resin
processing in a rigid mold JPD1973 (30) 339-
Dimensional accuracy of pour acrylic resin and
conventional processing of cold cure resin JPD
1970 (24) 662-
Atwood et al: final report of the workshop on
clinical requirements of ideal denture base
material ; JPD 196820) 101-105
3'd edition
Walter Shepard : fluid resin technique; JPD
1968 (19) 561-
Koblitz F.F et al: Fluid denture resin
processing in a rigid mold JPD1973 (30) 339-
Dimensional accuracy of pour acrylic resin and
conventional processing of cold cure resin JPD
1970 (24) 662-
Atwood et al: final report of the workshop on
clinical requirements of ideal denture base
material ; JPD 196820) 101-105
EW Skinner; acrylic denture base material their
physical properties and manipulation. JPD 1951
(1) 161-
Comparison of self curing and heat curing
denture base resins JPD 1953 (3) 332-
FA Peyton; evaluation of dentures processed by
different technique JPD 1963 (13) 269-
Cytotoxicity of denture base acrylic resin JPD
2003 (90) 190-
Bernard Levin et al; use of microwave energy for
processing acrylic resins JPD 1989 (61) 381-
physical properties and manipulation. JPD 1951
(1) 161-
Comparison of self curing and heat curing
denture base resins JPD 1953 (3) 332-
FA Peyton; evaluation of dentures processed by
different technique JPD 1963 (13) 269-
Cytotoxicity of denture base acrylic resin JPD
2003 (90) 190-
Bernard Levin et al; use of microwave energy for
processing acrylic resins JPD 1989 (61) 381-
* Robert EO; Comparison of accuracy between
compression and injection molded complete
denture JPD 1999 (82) 291-
« Glossary of Prosthodontic Terms 8
* A comparative in-vitro study on the adherence
and penetration of c. ALBICANS TO THREE
DIFFERENT RESIN DENTURE BASE SURFACE -
Dr. Divyang patel
compression and injection molded complete
denture JPD 1999 (82) 291-
« Glossary of Prosthodontic Terms 8
* A comparative in-vitro study on the adherence
and penetration of c. ALBICANS TO THREE
DIFFERENT RESIN DENTURE BASE SURFACE -
Dr. Divyang patel
Thank You
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