composition and structure

1. Dental Department
COMPOSITE RESTORATION
COMPOSITION AND
PROPERTES

2. Dr Jamal Hussein

4. RESTORATIVE
MATERlALS
Dental Composites
Dental composites are highly cross-
linked polymeric materials
reinforced by a dis- persion of
glass, crystalline, or resin filler
particles and/or short fibers bound
to the matrix by silane coupling
agent

5. Applications of Composites
1-Restoration for anterior and
posterior teeth
2-Pits and fissure sealants
3-Bonding of ceramic veneers
4-Cementation of fixed prosthesis5-Cementation of
Orthodontic brackets

7. CONTRA INDICATIONS:
1.High caries incidence and poor
oral hygiene.
2.Teeth with heavy or abnormal
Occlusal stress (bruxism).
3.If cases of access & isolation
difficulties.
4.Subgingival difficulties
5.Patient allergic or sensitive to resin
composite.

8. 1) Esthetics
2) Conservative tooth
preparation.
3) Insulative.
4) Bonded to the tooth structure.
5) repairable
ADVANTAGES

10. Three main components in dental
resin-based composites
1 – (continuous phase)
Matrix-A plastic resin material that
forms a and binds the filler particles
2. (dispersed phase)
filler-Reinforcing particles |fibers that
are dispersed in the matrix
3.(Interfacial phase)
Coupling agent-Bonding agent that
promotes adhesion between filler and
resin matrix

11. Composite restorative materials contain a
number of components in addition to the
three main components
1-An activator- initiator system is required
to convert the resin paste from a soft,
moldable filling material to a hard,
durable restoration
2- Pigments help to match the color of
tooth structure.
3-Ultraviolet (UV) absorbers and other
additives improve color stability,
4-polymerization inhibitors extend storage
life and pro- vide increased working time
for chemically activated resins

13. in Matrix (continuous phase)
Monomers
(mono = single) are the molecules that
unite to form a polymer, and the process by
which this occurs is termed polymerization
A polymer
is a molecule that is made up of many units
(poly = many; mer = unit).
A mer is the simplest repeating chemical
unit of which the polymer is composed

14. Copolymerscopolymers are formed from monomers of
two or more different types, are joined
togother

15. Most dental composites matrix use a blend of
aromatic and/or aliphatic dimethaclylate
monomers such as

16. BIS-GMA BisphenolAglycldilmethac
rylat
UDMA urethane
dimethacrylate
TEGDMA Triethylene glycol
dimethacrylate

17. Bis-GMA has a particularly high viscosity
(similar to honey), which makes it very
difficult to blend and manipulate and
less polymerization shrinkage
it is necessary to use lower- molecular-
weight, highly fluid monomers to dilute
Bis-GMA
.reduction in viscosity is significant
when(TEGDMA) is added to bis-GMA.
blend of 75 wt% bis-GMA and 25 wt%
TEGDMA has a viscosity of 4300
centipoise

18. UDMA, bis-GMA, and TEGDMA are widely used
Resin matrix ingredients

19. Polymerization

21. polymerization
The free-radical polymerization of t he matrix
monomers leads to a
Three dimensionalpolymer particles
--2 Molecules of monomer bond together called
double bond molecules
,-- linear propagating macro radicals molecules are
formed from double bond monomer molecule i
--During chain propagation, the macro radicals form
micro gel particles.
--The time between the initiation and the gel point is
called gel time
(2-3)SECONDS
--a three-dimensional (3D) polymer network is built
up.
From the initial stage until the polymerization

22. Filler Particles(dispersed phase)
1- inorganic substances
Filler particles are most commonly
A-quartz particles ranging in size from 0.1 to 100
pm
B-Submicron silica particles of colloidal size (-0.04
ym), referred as microfiller)
C-Groundglasses& ceramics with heavy metals
The radiopacity of filler materials is provided by a
number of glasses and ceramics that contain heavy
metals such as baliunl (Ba), strontium (Sr), and
zirconium (Zr2-organic substances
It is prepolymerized resin act as
copolymers{same structure of the resin matrix

23. Crystallization of fine-grained leucite glass-
ceramics for dentistry
Spherical Zr/Si-oxide
BA-F-silicate glass
-Ba-silicate glass
Si-dioxide
glass-ceramics
grained
• Crystalline quartz

24. purposes of filler particles
The primary purposes of filler particles are to
strengthen a composite and to reduce the
amount of matrix material
(1) reinforcement of the matrix by increasing the
hardness, strength, and decreased wear;
(2) reduction in polymerization shrinkage;
(3) reduction in thermal expansion and contraction;
(4) improved workability by increasing viscosity
(liquid monomer plus filler yields a paste
consistency);
(5) reduction in water absorption,
(6) increased radiopacity and diagnostic sensitivity
through the incor- poration of strontium (Sr) and
barium (Ba) glass and other heavy metal

25. Coupling Agents(interfacial phase)
Coupling agents are used to adherence of resin
to filler surfaces.
Coupling agents chemically coat filler surfaces
Coupling agent improve mechanical and
physical properties.Coupling agent is an organosilane such as
gamma methacryloxy propyl trimethoxysilane
The silane allows stress transfer between the
filler and the matrix.

26. The silane agent is a bifunctional molecule with a
methacrylate group on one end and a silanol group
on the other.
The methacrylate end undergoes addition
polymerization with the composite resin
the silanolend bonds to the hydroxyl groups on the
filler particle via a condensation reaction

30. Prevents spontaneous
polymer formation
heat
light
Extends shelf life
Butylated
Hydroxytoluene
Inhibitors

33. Conventional/traditional/Macro-filled
composites
filler is crystalline quartz, which has got excellent
optical properties, and chemical inertness . These
traditional quartz particles size are around 8-12
Most common types of composite res

34. Small-Particle-Filled Composites
improve surface smoothness
improve the physical and mechanical properties of
traditional composites,
SPF composites use amorphous silica as filler, but
most incorporate glasses that contain heavy metals
for radiopacity
inorganic fillers are ground to a size range of ~0.5 to
3 ym a broad size range distribution
. 'This broad particle-size distribution facilitates a high
filler loading
inorganic filler (80 to 30 wt0/0 and 65 to 77

35. Hybrid Composites
The most common filler today is barium glass with
average particle size of 0.6 to 1.0 microns.
A small amount of micro filler
hybrid composites contain two kinds of filler particles.
Most modern hybrid fillers consist of colloidal silica
and ground particles of glasses conta,ining heavy
metals, constituting a filler content of approximately
75 % 80 %wt
hybrid composites are widely employed for stress-
bearing, posterior restorations

36. Hybrid Composites

37. able Composites
A modification of the SPF and hybrid composites
results in the so-called flowable composites. These
resins have a reduced filler level so as to provide a
consistency that enables the material to flow
polymerization shrinkage of flowable composites is
higher than that of conventional or packable
composites
Class I restorations in gingival areas,which there is
poor .accessibility and little or no exposure to
wear,,fissure sealants

38. Packable composites“condensable”
are characterized by less stickiness and a
stiffer viscosity
Packable composites have a composition a
higher filler load or high concentration of
thickening fine particle fillers than
conventional restorative filling composites.
Flexural strength and modulus are due to the
higher filler load in most packable

39. classification system by Bayne and others, based
on particle size

41. megafill – 0.5 to 2 millimeters;
macrofill – 10 to 100 microns;
midifill – 1 to 10 microns;
minifill – 0.1 to 1.0 microns;
microfill – 0.01 to 0.1 microns
nanofill – 0.005 to 0.01 microns.
. The various groups
included

42. Most new systems are minifill hybrids with a trend
toward nanofillerNanofilled resin composites utilize nanometer-sized
particles throughout the resin matrix.
Nanohybrids combine nanometer-sized particles
with more conventional filler technology

43. Classification according to curing
system
Chemical Cure
Chemical activated resin
•Two pastes
• Initiator Benzoyl peroxide
Activator Tertiary amine

44. Light Cure
-UV - Light activated systems ::: It is the first light
activated system to activate the free radicals. -
(benzoin methyl ether was used as photo initiator
Supplied as ,,,,,,, Single paste system , containing
– Photoinitiator ----- Camphoroquinone 0.25 wt. %
Amine accelerator ----- DEAEMA 0.15 wt. %
Light sources:
Halogen light. (QTH)
Plasma arc light. Argon laser.
Blue light emitting diodes (LED

47. Light cur
Perpendicular to the composite material
Distance between the end of the lamp and the
composite material is 10mm
eye protector is recommended
 Polymerization time depends on the power of the
lamp:
 Halogen polymerization lamp: 400-800 mW: 40sec
Ledpolymerization lamp: 850-1200 mW: 15-20 sec
Dual cur
dual curing, i.e., they incorporate a combination of

48. DENTIN AND ENAMEL BONE
Acid Etching
Acid etching removes approximately 10 µm of
enamel surface and creates a morphologically
porous layer.
etching enamel by phosphoric acid 10 % or 37 %
. 15-second and 60- second etching
 The use of 10 % maleic acid n a lower bond
strength
(Bond) The low-viscosity fluid resin is attracted to
the micro porosities

49. Microstructu
re of enamel
etched with
phosphoric
acid

50. Microstructure
of enamel
etched with
phosphoric acid
Attachment sites of
polymer tags (T)
in etched enamel (E).

51. Selective etching
enamel only in case of
deep cavity

52. Total etching E+D

53. conditioners:
phosphoric acid
nitric acid
maleic acid
citric acid
(EDTA)
Dentin Bonding
Dentine bonding agents materials used to make a
dental composite filling
material adhere to bond to both dentine and enamel
Smear layer is microscopically thin and consists of
minor tooth particles after cavity preparation closing
the dentinal tubule
primer coupling agents
2-hydroxyethyl
methacrylate (HEMA),
4-methyloxyethy
l trimellitate anhydride
(4-META), glutaraldehyde
Bonding resins,
bisphenol
glycidyl
methacrylate
(bis-GMA)
or urethane
dimethacrylate
(UDMA)

54. Bottle 1 Bottle 2 Bottle 3
Conditioner Primers Bonding
resins
phosphoric acid
nitric acid
2-hydroxyethyl
methacrylate
(HEMA
bisphenol
glycidyl
methacrylate
(bis-GMA ) or
maleic acid 4-methyloxyethy
l trimellitate anhydride
urethane
dimethacrylate
(UDMA)
citric acid (4-META),
glutaraldehyde
(EDTA)

55. Conditioner
The smear layer is removed completely using
phosphoric acid (35%, bottle 1) (dentine
conditioning). Dentine conditioning is also referred
to as 'total etch' as the cavity (enamel + dentine)
is completely treated with acid.Primers
A molecule (HEMA = hydroxyethyl methacrylate)
dissolved in organic solven is applied to this
structure of collagen fibres which is both
hydrophilic and hydrophobic forming hybrid
layer(collagen fiber+monmer resin) (primer, bottle
2)

56. Adhesive (bonding agent)
Bonding resin will penetrate into the dentine
tubules and develop finger-shaped protrusions
referred to as Resin tags after polymerized

59. 1-TOTAL ETCH 3-STEP
ETCH–PRIME–BOND
2-TOTAL ETCH 2-STEP
ETCH–PRIME/BOND
3-SELF–ETCH 2-STEP
ETCH/PRIME–BOND
4-SELF–ETCH 1-STEP
ETCH/PRIME/BOND
5-SELECTIVE-ETCHING 3-
STEP ETCH–ETCH/PRIME–
BOND
6-SELECTIVE-ETCHING 2-
STEP ETCH–
ETCH/PRIME/BOND

60. Smear layer is closing the dentinal
tubule
after cavity preparation

65. PULP© M.Lenhard

66. PULP© M.Lenhard

67. PULP
COMPOSITE
© M.Lenhard

68. 1-Simle Design for ant teeth
2. Tooth Color
3. Tooth Shape
4. Tooth Position
5. Composite Selection
6. Tooth Preparation
7. Bonding Techniques
8.Composite Placement
9. Composite Polishing
PRINCIPLES OF
COMPOSITE
RESTORATION

73. Rules for Successful Composite Resin
Restorations
composite material chooses is not the only
factor in the success or failure of a
restoration.
many studies have shown that 50% of the
dentists worldwide use light-curing devices
that transmit energy below the accepted level
(600 mW/cm2) resulting in
postoperative sensitivity,
early discolorations of the restorations,

74. The success of a composite restoration
depends on 3 main factors:
1- the selection of a good quality
composite;
2- proper use of an appropriate bonding
system;
3- a light-curing system is capable of
delivering enough energy to complete
the polymerization process.
any technical error during one of those

75. EVOLUTION OF COMPOSITE RESINS
, many classifications of resin composites have been
introduced.
Most of these have differed mainly in the particular filler
system used;
l traditional, microfine or small particle composite filled
with silicium dioxide microfillers, and hybrids
(microhybrid, minihybrid, submicron hybrid, and
nanohybrid.)
1-Traditional composites the main shortcomings
a lack of life aesthetics

76. 2-microfine composites It is weaker mechanical
properties.
3-Hybrid composites contain large filler particles and
a small amount of colloidal silica (SiO2) to produce a
material with higher filler loading.1 They combine
good aesthetics with physical and mechanical
properties being better than traditional and small
particle filled composites
4-. Flowable composites, with lower filler content
and smaller particle size, have a low viscosity. their
use: pit and fissure sealants,
repair of marginal defects, liners in deep cavities,
a direct restorative material for class V restorations.
.

77. 6-, nanocomposites similar behavior to microhybrid
composites.
, nanocomposites should not be considered a
completely unique category.
7-polymerization shrinkage has not yet been totally
eliminated in composite resin
8-Composites resins are organic and the inorganic
fraction it have different viscosities. In fact, the
5-Packable composites, (high-density composites),
(“condensable” composites), are materials with
“supposed” higher filler content for
posterior useit can be difficult to polish. “.

78. THANK YOU