heat cure and cold cure

1. 1
Prosthetic Resin Polymers
Dr Layla Abu-Naba’a
PhD, MFDRCS
Assistant Professor of Prosthodontics

2. 2
Demographic changes
Means an increased need for Prosthetic treatments
20
30
40
50
60
1941 1982 2025 2050
%
population
over
50
0

3. 3
Prosthetic Uses
 Denture bases
 Denture teeth
 Relining Materials
 Repair of dentures
 Provisional acrylic
partial dentures
 Custom impression
trays
 Mouth guards
 Fluoride and
bleaching trays
 Facing on esthetical
crowns
 Provisional
restorations
 Removable tooth
movement devices
 Orthodontic retainers
6

4. 4
Denture base function
Distributes pressure over a wider area
So reducing bone resorption
Retains artificial teeth
Replaces missing tissue
Forms a seal for retention
6

5. 5
Denture Base materials
Carved ivory
Carved Wood
Vulcanite; dark, opaque
(Vulcanised rubber)
Highly cross-linked Acrylic resin
Other Resin and plastic
alternatives
0

6. 6
Plastic acrylic teeth
Bind chemically to the denture
Can be adjusted
Not cause wear of opposing tooth
Good colour match
Minor resiliency
Wear under high force occlusion
May stain with time
6

7. 7
Porcelain (high fusing ceramic)
Isosit (composite; xlinked acrylic) –
heavily xlinked
Experimental fiber-reinforced teeth
6
Other Teeth Materials

8. 8
Maxillofacial prosthesis
Needed
After trauma
Surgical defects
Birth defects
Other materials
Silicone rubber
Vinyls with
plasticizers
6

9. 9
Acrylic repair
Materials
Chemically cured acrylic
Light cured acrylic
6

10. 10
Relining Materials
6

11. 11
Provisional partial dentures
6

12. 12
Impression trays
6

13. 13
Record bases
Materials
Cold-curing acrylic resin
Other material
Shellac
Vacuum formed vinyl or polystyrene
Baseplate wax.
6

14. 14
Occlusal Splints
Night guards
Bleaching and fluoride
application trays
6

15. 15
Mouth guards
6

16. 16
Orthodontic applications
 Removable tooth movement devices
 Orthodontic retainers
6

17. 17
Facing of crowns
Provisional restorations
6
Other materials:
•Polycarbonate
•Aluminum
•Stainless steel
•celluloid

18. 18
Polymer principles

19. 19
Terminology
Monomer + monomer = polymer
Monomer1 + monomer2 = copolymer
Oligomonomer= 2-4 monomers
Poly = many
Mono = single
Mer = unit
Oligo =several
6

20. 20
Types and molecular weight
Addition polymerisation:
No by products
Polymer mwt = Σ mwt monomers
Condensation polymerisation:
By products are produced and lost in
thefinal product
Polymer mwt ≠ Σ mwt monomers
6

21. 21
Morphology
of spatial arrangements
Linear or chain polymerisation
Easily manipulated, stretched, bent,
thermoplastic, Hard
e.g. fitting surface of acrylic teeth- better
binding to denture base
Branched polymerisation
Easily manipulated, stretched, bent,
thermoplastic, More hard
6

22. 22
Cross-linked polymerisation
Strong, stiff, thermoset, wear resistant
E.g. Denture base materials, Occlusal
surfaces of actylic teeth
Coiled chains
Flexible
e.g. impression materials
Morphology
of spatial arrangements
6

23. 23
Crystalline polymers
Very regular arrangement in space:
strong,
stiff,
absorb less water.
Amorphous or glassy polymers
Irregular arrangement
Behaves as a brittle solid
Morphology
of spatial arrangements
6

24. 24
Plasticizers effects
Added to stiff, glassy uncross-linked
polymers
Lowers glass transition temperature (Tg)
Become
rubber-like,
Flexible
less brittle
6

25. 25
Dimensional and thermal
changes
Expansion on polymerization, exothermic
Contraction on polymerization
21vol.% If unfilled acrylic resin
6% denture resin
1-3% composites
Expansion on swelling in water
Expansion or warpage on thermal change
and reheating
6

26. 26
Acrylic Resin Types

27. 27
Ideal properties
Natural appearance
Easy processing
Easy to clean
Easy to repair
Inexpensive
Biocompatible
Resistant to bacterial
contamination
High strength, stiffness,
hardness, toughness,
fatigue resistance
•Low density
•Radiopaque
•High thermal
conductivity
•High modulus of
elasticity, impact
strength
•Abrasive resistance
•Dimensionally stable
•Accurate reproduction
of surface detail

28. 28
Curing methods
Chemically cured
Tertiary amine ( dimethyl-p-toluidine or sulfinic acid)
(accelerator)
Benzoyl peroxide (initiator)
Hydroquinone (inhibitor)
Heat cured
Heat and pressure control
Avoids porosity
Maximizes conversion of monomer to polymer
Light cured
Photo-initiators (camphorquinone),
Blue light,
Used for: record bases, custom tray, denture repair

29. 29
Heat cured acrylic resin
Powder ( can have limitless life)
Beads or granules of polymethyl methacrylate
Initiator (benzoyl peroxide)
Pigments/dyes (colour vitality as cadmium, iron, organic dyes)
Optical opacifiers (tio2/zno)
Plasticizers (ethyl acrylate (internal), dibutylphthalate (external) to
make dough easier)
Synthetic fibres (nylon)
Coloured fibres (blood vessels)
Liquid ( in dark bottle, avoid contamination by
powder)
Methyl methacrylate monomer
Inhibitor (hydroquinone)
Crosslinking agent
(diethylene glycol dimethacrylate, (1,4 butylene glycol dimethacrylate)
Bead Polymer

30. 30
Chemical cured resin
Cure is initiated by a tertiarv amine (e.g. Dimethyl-
p-toluidine or sulfinic acid)
Absence of heat:
Lower molecular weight material
Lower strength properties
Higher residual monomer in the resin
Color stability is not as good- yellowing
Less contraction on cooling to room temp
Polymer beads are smaller
Faster dissolution in the monomer to produce a dough
Doughy stage is reached before the addition curing reaction –
mix viscosity is high and prevents the adaptation of the mix to
the mould walls or cast -keep readapting
Lowering of the glass transition temperature
Less build-up of internal strain
Highly susceptible to creep- distortion when in use.

31. 31
Light activated materials
Components:
Urethane dimethacrylate matrix
Acrylic copolymer
Silica filler to control rheology
Forms
Sheets
Ropes
Curing
Light chamber- 400-500 nm
Photo-initiators (camphorquinone),
Teeth added in a second exposure over the base
Used for
Record bases
Custom tray
Denture repair
Hardness and impact strength ≈ heat cured resin
Elastic modulus < heat cured resin; deform under
mastication
Less shrinkage (3%) better fit
Less residual monomer

32. 32
Auto-polymerizing, pour acrylic
Reducing agent (tertiary aromatic amine or barbituric
acid derivative, NN’-dimethyl-p-toluidine) reacts with
peroxide at room temp.
Excellent detail reproduction
To be able to pour in mold, balanced size, mwt,
plasticizers and xlink agents
Reversible hydrocolloid (agar) mold can’t resist teeth
movement during pouring
Hydro pressure flask reduces air bubbles and
monomer porosities
Difficult to dewax, less monomer binding to teeth
Shortcomings:
residual monomer
↓ Cross link densities
 Creep
 Variety of products

33. 33
High-impact acrylic
A rubber phase is added (phase inversion)
Uniformly distributed
Rubber cored polymer
Types
Butadiene + styrene = polystyrene butadiene rubber
Butadiene + MMA
PMMA + polystyrene butadiene rubber + poly(2,3-
dibromopropyl methacrylate) for opacity
PMMA = lucitone 199
Lightly xlinked or no cross linking agent is added
Rubber has a craze inhibitory effect

34. 34
Experimental types of acrylic
All aim to increase impact strength and stiffness
Glass reinforced acrylic (failed)
Fibers may irritate patient if denture fitting surface was
abraded
Carbon fibers
Black color- used only in lingual areas
Kevler fibres (poly-p-phenylene terephthalamide)
Straw color
Poor bond between fibers and matrix
Difficult to pack
Black shadow- used only in lingual areas

35. 35
Experimental types of acrylic
Added Bis-GMA and fiber
Flexural strength ≈ ceramics
Can be used as lingual bars and connectors
Experimental (mwt polyethylene fiber-reinforced)
Neutral color
Low density
Biocompatibility
Surface treated to enhance fabrication
Time consuming

36. 36
Types of acrylic
Other (polystyrene,epoxy, SS)
PMMA Adhesion to
Metal- use adhesive primers
untreated porcelain teeth with organo
silane compounds

37. 37
Heat Cured Resin

38. 38
Polymethyl methacrylate
Activation
Initiation
Propagation
Termination
MMA
Liquid
PMMA
Powder
Old and new
polymer chains
Intertwined at the
molecular level.
PMMA
Powder
Particle swells
MMA
Liquid
Acrylic dough (Cohesive gel)
Heat and pressure
(entanglements)

39. 39
Setting reaction
Mixing of powder and liquid cause monomer diffusion and
softening of the surface of the powder producing the following
gelling stages:
Ratio P/L (2/1 wt%, 1.6 -1 vol%)
Sandy- initial melting of beads (not used)
Stringy or sticky- entanglements with swollen beads and
thickened interstitial monomer (not used)
Dough- gelation (used)
Rubbery- monomer penetrates to the core of beads,
plasticizing them, ↓Tg (not used)

40. 40
Manipulation issues
P/L
Inadequate filling by monomer
Weak material properties
Porosity
↓P/L
Excessive polymerisation shrinkage
Poor fit
Light color as powder holds the pigments

41. 41
Manipulation issues
Curing before monomer diffuse to bead
(before dough stage)
↓ flexural strength
cracks between linear polymerised interstitial gel and cross
linked beads
More shrinkage contraction by the loss of pressure produced
by the dough to compensate for it
Curing in dough stage
monomer penetrate the beads
dissolves beads allows cross-linking agent to penetrate
interpenetrating polymer network IPN.
Packing in the rubber stage
Less extrusion of excess acrylic from flask
Extra pressure in the mould
Fracture the cast
less flow around teeth
Dislodgment of teeth into mould

42. 42
Manipulation issues
Control of color
Pigments position
Inside beads
surface of beads
– polymer should be added to the monomer slowly so it will not
washed off by too rapidly
Blood vessel resembling Fibers aggregate in the bottom
of bottle
– Shake powder well before use
Mould Lining
resin may penetrate rough plaster and adhere
a separating medium must be employed
solution of sodium alginate
tin foil.

43. 43
Manipulation issues
Control of Processing strains
Shrinkage in restricted mould cause internal strain
On release of stress (flask opening) it may give
Crazing
Warpage
Distortion
These are reduced by the slightly extra packed material
that flow into shrinkage spaces when temperature is
higher than Tg (heated flask)
Manipulation further reduces strains by
Using acrylic teeth
Cooling the flask slowly

44. 44
Flasking steps
Flasking
Dewaxing
Putting a separating medium
Placing acrylic dough
Packing
Heat curing

45. 45
Wax-up
Flasking
Melt out the wax
Packing
Curing

46. 46
Flasking for heat cured resin
Flasking options with acrylic dough:
Trial-packing, trimming, repacking
Packing-only
Poured resin (e.G., Lucitone fas-por)
Injection moulding
Heat and pressure control
Aim to produce radicals and initiate polymerization
Reaction is thermally activated and generates heat as
well
Reaction conversion is about 98 to 99.5%
MMA: tbp = 100c (p= 1 atm); 140c (p= 2 atm)

47. 47
Heat curing cycles
Fast cycle
Cure at 71-72°C for 30-90 min
100°C for 30 min.
Slow cycle = cure at 71-72°c for 10 hrs
[A slow cycle is better with larger amounts of
material.]
[Generally, slow cures result in better
dimensionalaccuracy.]
Other cycles are done as recommended
by manufacturers

48. 48
Heat curing cycles
Rapid heating:
Excess radical release
Extra xlinking and branching of interstitial
polymer
More residual monomer
Reduced toughness
Heat builds up from exothermic rxn
Porosity
Loss of strength
Bad esthetics (opaque and cloudy color)
Possible fouling

49. 49
Heat curing cycles
Slow :
Sufficient radical release
Adequate xlinking and branching between high
mwt polymer chains
Increased toughness
Sufficient radical ends increase monomer
incorporation in growing chains
Xlinking agents polymerized, reducing their
plasticizing effect (in their non bound state) and
reduce creep
Produce an annealing effect easing stresses
produced from shrinkage, reducing crazing and
distortion

50. 50
Heat curing cycles
Pressure control
Places compressive force
Compensates for polymerization shrinkage
Increase flow of dough around teeth, more
monomer wetting and surface dissolution,
stronger bond
Oozes out excess dough
Some hybrid systems begin polymerization
from one side to allow dough to cover for
shrinkage

51. 51
Heat curing cycles
Microwave curing
Uses a microwave
Flasks are non metalic
Reduced time

52. 52
Denture shortcomings

53. 53
Denture Radiolucency
Problems when accidents displace fractured
segments
Lungs
Skull
stomach
Salts and fillers reduce esthetics, strength
Organo-metalics are toxic
Bromine containing organics lack heat stability, must be
added in quantities that plasticize the denture, causing creep
and water sorption
Phase separating bromo-polymer in beads reduce the
previous effects

54. 54
Mechanical properties
Failure to Moderate strengths:
impact resistant denture is low
Low elastic and flexural modulus
lack of fracture toughness
30% of denture repairs involve midline fractures
which are most prevalent among upper dentures.
dropped denture does not necessarily break instantly
a crack continue to grow and failure due to flexural
fatigue.
Failure due to poor quality processing
Lack of bonding between the resin and the acrylic teeth
and weak interface
Crazes due to processing faults or exposure to solvents
is another possibility.
Creep
Reduced by cross linking
Heat cured < cold cured

55. 55
Internal denture porosity
Inherent porosity:
Not seen by vision
1-2% of residual
monomer
Leaks
Replaced by fluids
Minimized by
Use heat cured resin
Pack denture under
correct pressure
Use correct P/L
Use the glaze after
polishing

56. 56
Internal denture porosity
Irregular porosity:
Seen by vision
Not regular on
denture surface
P/L heterogeneity
Air incorporation
(spherical pores)
Minimized by
Use correct P/L
Add liquid first
Mix well
Cover the mix before
dough stage
Can use the vibrator

57. 57
External denture porosity
Irregular surface
deficiencies:
Seen by vision
Insufficient pressure
Dough was not molded
correctly by hand leaving
surface blisters and pores
Insufficient dough
Minimized by
Mold dough by hand
into small areas
Place sufficient
material in flask
Pack under correct
pressure

58. 58
External denture porosity
Irregular porosity:
Shrinkage by
polymerisation (5-8% vol
or 0.2 -0.5% linear)
Further shrinkage by
cooling to room
temperature
Can compensated for by
the post dam technique
Minimized to by
Pack under pressure
Slight extra denture
material can overcome
shrinkage and
maintain pressure
(single packing)
Pack in dough stage

59. 59
Internal denture porosity
Gaseous porosity
Seen by vision
Volatisation of
monomer by
Localized MMA boiling
Common in thicker
portions
Minimized by
Avoid high processing
temperatures
Avoid extra monomer
than recommended for
P/L
Raise heat slowly and
evenly around the
flask

60. 60
Gaseous porosity
Avoid high processing temperatures
0
20
40
60
80
100
120
140
160
0 10 20 30 40 50 60 70 80 90
100
Temperature
0
C
Time (min)
Correct
cycles
Incorrect
cycle

61. 61
Crazing
Area of localised region of high plastic
deformation which may fill by voids
Crazed region can still support stress
As the voids in the crazed region grow, they become
separated only by thin fibrils of polymer
Fibrils fail and a crack is formed
Crack will grow under an externally applied load
Cause denture failure by brittle fracture.
Caused by
Internal strains in flask
Heat (due to polishing)
Differential contraction around porcelain teeth
Attack by solvents such as alcohol
Reversible Irreversible
CRAZE CRACK

62. 62
Crazing
Avoid internal strain during polymerisation
Slow cooling of the flask
Use single trial packing
Use cross linked polymer types
Avoid extra stress during function
Use acrylic rather than porcelain teeth
Do not overheat on polishing
Keep denture away from solvents
Avoid denture drying
Polish after each adjustment
Use glazes for surface
Reversible Irreversible
CRAZE CRACK

63. 63
Dimensional changes on
processing
Expansion on heating flask; heat evenly
Expansion on polymerization, exothermic
Contraction on polymerization (21vol.%);
Contraction on cooling to room temperature;
Expansion on swelling in water;
Expansion on thermal change to 32c.
Net result– should be near zero

64. 64
Warpage on drying
Contraction on evaporation of
absorbed water
Don’t leave denture outside the mouth
dry

65. 65
Adverse reactions to PMMA
Most common in dental
laboratories
Associated with regular
contact with monomer
when handling the
dough
Must avoid direct
contact
Rubber gloves may not
provide sufficient
protection
Barrier creams can help
Irritant contact
dermatitis

66. 66
Adverse reactions to PMMA
Allergic contact dermatitis
Usually associated with
release of
residual monomer
Benzoic acid
Types
Immediate
Delayed hypersensitivity
(type IV)
Heat cured resin < chemical
cured
Must ensure full cure of denture
Avoid relining procedures
May use an extra cycle of
polymerisation – but denture
may warp
May need to consider
alternative material such as
polycarbonate if Delayed
hypersensitivity

67. 67
Adverse reactions to PMMA
Further reading:
Hensten-petterson & jacobsen. J prosthet dent
1991; 65: 138
Kaber. Int dent J 1990; 40: 359
Http://www.Shef.Ac.Uk/uni/project/arrp/

68. 68
Thermal properties
Low Thermal conductivity
during denture processing heat cannot escape – prone to
gaseous porosity
isolates from any sensation of temperature – throat burns
High Coefficient of Thermal Expansion
Porcelain teeth may be lost due the differential expansion
and action
Warpage if denture is cleaned with hot water

69. 69
Water Sorption
PMMA will absorb water by polar nature (1.0-2.0%
wt)
May compensate for processing shrinkage
Weeks of continuous immersion in water to reach a
stable weight
Solubility
Solvents (e.G. Chloroform, alcohol)
Xlinked are insoluble in most of fluid intakes
Weight loss will occur, due to leaching of the
Monomer
Pigments and dyes.

70. 70
Ideal properties achieved?
Natural appearance 
Easy processing 
Easy to clean 
Easy to repair 
Inexpensive 
Biocompatible 
Resistant to bacterial contamination x
High strength, stiffness, hardness, toughness X
Low density 
Radiopaque X
High thermal conductivity X
Dimensionally stable X
Accurate reproduction of surface detail 

71. 71
More
DB bonding to alloy framework
Acrylic-metal leakage

72. 72
Other Denture Base materials

73. 73
Injection molded plastic
Types
Polycarbonates
Nylon
Advantage:
Consistent mwt
Substitute acrylics in sensitive patients
Disadvantage
Must use dry mold, slow heating and cooling
Under filled molds by inadequate spruing or underheating
Low melt temp cause high injection forces, moving teeth in
mold
Cost of equipment
Difficult to attach to teeth
Small market segment
Can explode if high heat and wet molds
Overheating cause depolymerization, oxidation, porosties
Loss of strength
Bad esthetics (opaque and cloudy color)
Possible fouling

74. 74
Polycarbonates
Tough plastic
Injected in dry molds
A high melt viscosity
Problems in binding to teeth
May de-polymerize explosively in the
presence of heat and water
No cross linking –
Poor solvent resistance
Poor craze resistance

75. 75
Nylons and polyamides
Polyamide = diacid + diamine
Conventional nylon failed
Excessive water sorption
Poor creep resistance
Biodegradation
Glass (beads or fibers) reinforced nylon
Less water sorption
Fibers better in stiffness(≈ acrylic) than beads
Fibers may irritate patient if denture fitting surface was abraded

76. 76
Cellulose product
Camphor used as plasticiser
Warpage in mouth
Camphor leached out
Loss of color
Taste
Blistering
Staining

77. 77
Phenol Formaldehyde (Bakelite)
Difficult to process
Lost its color with function

78. 78
Vinyl resins
Low resistance to fracture
Fatigue failure

79. 79
Relining Materials

80. 80
Denture base reprocessing:
Hard and soft tissue changes every 5-8 years
Require modifying denture base:
Relining  resurfacing of the tissue surface
Rebasing  replacement of entire denture
base

81. 81
Soft denture lining material
Uses:
After surgery
Immediate dentures
Sores
Undercuts which are not removed by surgery
Ill fitting denture
can be done
In lab
Chair side

82. 82
Ideal lining material properties
Durability: but hardens in short time
(1-4w, 1-3 y)
Dimensional stability
Resistance to fouling
Water absorption
Osmotic presence of soluble material
Resistance of Biodegradation
Could it bond old acrylic
Inhibit candida growth

83. 83
Lining materials–acrylic based
Glassy MMA + high conc. of plasticizers
Plasticizers:
Free: diffuse out reducing the resiliency
Bound in cured matrix – failed clinically
Has lower rate of polymerization
Phase separation
Water accumulate in plasticizer rich phase
Soluble impurities cause more osmotic pressure
Swells and distorts
Discoloration
Bad taste
Exothermic rxn
Bad taste

84. 84
Lining materials–acrylic based
Soft acrylics that have ↓Tg
EMA (ethylmethacrylates)
Beads coploymer
Ethyl methacrylate + isobutyl methacrylate
Ethyl methacrylate + ethoxyethyl methacrylate
– Have unpleasant odour
Monomer
MMA Tg > room temp Less irritant to patients
Isobutyl methacrylate Tg < room temp (polished after placing
in iced water), Dimensional instability
Plasticizer in monomer trapped in beads (25-50%)
Phthalate ester – leach out by time
Avoid heat, strong bleaching agents that reduce resilience

85. 85
Lining materials–acrylic based
Soft acrylics that have ↓Tg
Hydroxy EMA
Water is the plasticizer
Swelling of liner may make it distort
Ions enter and may crystallize inside matrices thus
hardening the liner
Polymerisable plasticisers
Beads ploymer
Ethyl methacrylate + isobutyl methacrylate or
Monomer
Alkyl maleate or
Alkyl itaconate + Tridecyl methacrylate +
2-diethylhexyl maleate, ethylene glycol dimethacrylate

86. 86
Tissue conditioners
Differ from soft lining material by the following
Different viscoelastic properties
Flowable on insertion responding to
– Masticatory forces
– Lingual forces
– Border moulding forces
Increase viscosity on setting
Flows slowly responding to persistent heavy masticatory
forces after setting
– Useful to fill space after tissue swellings resolve
– Can be used as a functional impression
Reaction
Gel formation not polymerization
Alcohol swells beads and ↓ their Tg
Beads become tacky by entanglements and  cohesive
strength

87. 87
Tissue conditioners
Differ from soft lining material by the following
Composition
• Old- plasticine
• Old- chewing gum
• Ethyl methacrylate copolymers
• Or small mwt polymers
Plasticisers:
ethyl alcohol or
aromatic esters (butylphthalyl butylglycolate)
hemical cleaning damages the liner
– Use plain soap and water

88. 88
Tissue conditioners
Differ from soft lining material by the following
Alcohol problems:
Leak and replaced by water- so harden days up to 14 days
High conc. Can give a sting sensation
Can give a false positive on breathalyser test
Reduce leach of plasticisers by glazing or semiset MMA
Very susceptible to infection
– Incorporate antimicrobials as
» silver zeolite
» itraconazole
Chemical cleaning damages the liner
– Use plain soap and water

89. 89
Silicon - RTV
Room temperature vulcanizing silicones (RTV)
Polymethyl siloxane polymer
It sets by crosslinking of existing polymers
Heat
Tetraethyl silicate
Condensation minimal xlinking
Poor tear resistance
Poor abrasion resistance
Poor adhesion to denture
Use adhesive or coupling agent
Osmotic pressure effects
Buckling and swelling with water
Poor resistance to cleansers
Biocompatible
Dimensional stability
May foul by Candida

90. 90
Silicon – Heat cured
More xlinking
Poor tear resistance
Adequate adhesion to denture
Can use siloxane methacrylate as a binder to heat
cured additional silicon
Resistant to aqueous environment and Osmotic
pressure effects
better resistance to cleansers
Poor tear resistance
Poor abrasion resistance

91. 91
Other acrylic products

92. 92
Denture base hygiene
1. Clean with toothbrush and warm soap-
and-water
2. Use low abrasive cleaners
2. Avoid oxidizing or Cl-containing
materials
• Bleaching the color
• Reduces strengths of denture
• Reduces fatigue resistance
3. Diligently clean both the top and tissue-
borne surfaces
4. Clean with benzalkonioum

93. 93
Thank you

94. 94
References
Philips Science of Dental Materials
Dental Materials and Their Selection
Applied Dental Materials
Dental Materials. Clinical Applications for
Dental Assistants and Dental
Introduction to Dental Materials
RPD acrylic materials by Dr Stephen C.
Bayne
Dr Layla Abu- Naba’a