composite resin and its application in dentistry

1. COMPOSITE RESIN
BY DR IPSITA PATHAK
JR II

2. CONTENTS
• Introduction
• Definition
• Classification
• Composition
• Advantages & disadvantages
• Types of composite
• Steps of clinical procedure
• Tooth preparation procedure
• Techniques
• Light curing units
• Failure of composite

3. INTRODUCTION
• Mercury-containing dental amalgam restorations are
being replaced with dental composites as the
restorative materials of choice mainly because of the
inherent esthetic appeal of the latter and the long-
standing controversy related to the toxicity of the
former.

4. • Composites are used because overall properties of the
composites are superior to those of the individual
components. The fact that dental composite materials
continue to improve in strength, abrasion resistance,
ease of application, translucency and polishability
rapidly increased their use in the first decade after
being introduced and continues to increase their
popularity.

5. DEFINITION
• According to Philip’s composite can be defined as a
compound of two or more distinctly different
materials with properties that are superior or
intermediate to those of individual constituents.
• According to Skinner’s A highly cross linked
polymeric material reinforced by a dispersion of
amorphous silica, glass crystalline or organic resin
filler particles and or short fibers bonded to the
matrix by a coupling agent.

6. CLASSIFICATION
• Composite can be classified based on the filler size ,
percentage of fillers loading, type of resin matrix,
viscosity, methods of polymerization and uses .

7. On the basis of the mean particle size of major
fillers (skinner’s)
• A)Traditional /Conventional / Macrofilled
Composites:- 8-12 µm
• B) Small Particle Filled Size- 1-5µm
• C) Microfilled Composites - 0.01- 0.04 µm
• D) Hybrid Composites- 0.6 – 1.0 µm

8. On the basis of filler particle size and distribution
( Bayne & Heymen classification)
• a) megafilled composites -(1-2µm)
• b) macrofilled composites-( 10-100µm)
• c) midifilled composites-(1-10µm)
• d) minifilled composites- ( 0.1-1µ m)
• e) microfilled composites- ( 0.01- 0.1µm)
• f) nanofilled composites-( 0.001-0.01µm)

10. On the basis of viscosity(Summit)
• A)conventional
• B) Packable
• C) Flowable

11. ON THE BASIS OF THE METHOD OF
POLYMERIZATION
• A) Selfcure/ Autocure / Chemical cure
• B) Light cure
1. Uv light
2. Visible light cure
• C) Dual cure – combine of both self cure & light cure
• D) Staged-curing composites-initial soft start
polymerization followed by complete polymerization.

12. BASED ON THE MODE OF
PRESENTATION
1.Two paste system
2.Single paste system
3.Powder-liquid system

13. ON THE BASIS OF THEIR CHRONOLOGICAL
DEVELOPMENT(MARZOUK)
• A) first generation: consist of macro-ceramic
reinforcing phases in resin matrix
• B) second generation : consist of colloidal and
micro-ceramic phases in continuous resin phase
• C) third generation : consist of hybrid composite ,
having combination of macro and micro ceramic
reinforces in a suitable continuous resin phase

14. • D) fourth generation: consists of hybrid composites
having heat cured, irregularly shaped, highly
reinforced , composite macro particles with a
reinforcing phase of microceramics
• E) fifth generation: consist of hybrid composites ,
having continuous resin phase reinforced by
microceramics and macro , spherical , highly
reinforced , heat cured composites particles.

15. • F) sixth generation : consist of hybrid composites ,
having continuous resin phase reinforced with a
combination of micro-ceramics and agglomerates of
sintered micro ceramics.

16. INDICATION
• Class I II III IV V VI
• Core build ups sealants and preventive resin
restorations
• Esthetic enhancement procedure
• Temporary restorations
• Periodontal splinting
• Orthodontic bonding
• Patients allergic to metal
• Composite inlays

17. CONTRAINDICATION
• Isolation difficulties
• Teeth with heavy or abnormal occlusal stress
• Subgingival area
• High caries index
• Habits(bruxism)
• If patients allergic to composite

18. ADVANTAGES
• Esthetics
• Conservation and less complex
• Used almost universally
• Bonded to tooth structure
• Repairable
• No corrosion
• No health hazards

19. DISADVANTAGES
• Polymerization shrinkage
• Technique sensitive
• Higher coefficient of thermal expansion
• Time consuming
• Staining
• Increased occlusal wear
• Low modulus of elasticity
• Costly

20. COMPOSITION
• Composite resin are composed of four major
components, which are resin matrix, filler particles,
coupling agent and activator-initiator system.
Resin Coupling
agent
Filler

22. • The resin matrix is a continuous phase into which all
the other constituents are added. It is composed of
aliphatic or aromatic diacrylates of which the two
commonly used resin is formed by reaction between
bisphenol A and glycidyl methacrylate. It is highly
viscous. Diluent monomers such as triethylene glycol
dimethacrylate are added to reduce the viscosity and
allow filler particles to be added.

23. • Dispersed in the resin matrix are the inorganic filler
particles. Filler provide dimensional stability to the
soft resin matrix.

24. • For the composite material to perform well the filler
particles have to be well bonded to the resin matrix.
This is achieved through coupling agents. Silane
contains functional groups, which hydrolyze and
react with inorganic filler as well as unsaturated
organic groups. Thus they are responsible for the
bond between inorganic and organic phase of
composite; hence promote stability to the system.

25. • Activator-initiator system help in generating free
radicals required for starting the polymerization
reaction. However, to counteract spontaneous
polymerization of the monomers, inhibitors like
butylated hydroxyl toluene are provided. Optical
modifiers are added in minute quantities to produce a
variety of shades in the material.

26. CONSTITUENT EXAMPLE FUNCTION
Resin matrix BisGMA, UDMA,
TEGDMA
it is a continuous phase to which other
ingredients are added such as fillers,
activator-initiator system, inhibitors etc
FILLERS Zirconium oxide
Crystalline quartz
Borosilicate glass
Lithium/barium
aluminium silicate
Silicon dioxide
Aluminiumdioxide
Fillers are added to improve the physical
properties of the resin matrix such as;
Decrease polymerization shrinkage
Decrease coeff of thermal expansion
Increase the hardness of material
Makes the material more resistant to
wear
Decrease water sorption

27. CONSTITUENT EXAMPLE FUNCTION
OPTICAL
MODIFIERS
Aluminium oxide
Titanium oxide
Metal oxides added in minute amounts
Produce different shades in composite
COUPLING
AGENT
Organosilanes like It bonds fillers particles to the resin
matrix.
This allows the more flexible polymer
matrix to transfer stresses to the stiffer
filler particles.

28. CONSTITUENT EXAMPLE FUNCTION
ACTIVATOR ,
INITIAOR
SYSTEM
CHEMICAL
CURE
INITIATOR
ACIVATOR
LIGHT CURE
ACTIVATOR
INITIATOR
Benzoyl peroxide
Tertiary amine
UV light source/ visible
light
Benzoin methyl ether/
camphoroquinone
Generates free radicals to initiate
addition polymerization reaction
INHIBITOR Butylated hydroxy toluene they minimize or prevent
spontaneous polymerization of the
monomers.

29. PROPERTIES

30. LINEAR COEFFICIENT OF THERMAL
EXPANSION
• It is a property, which determines the rate of
dimensional change of a material per unit change in
temperature .
• Ideally for any restorative material LCTE should be
either coinciding or close to that enamel .
• This is important for the success of the restoration , as
it reduces creation of a gap or voids a tooth
restoration junction with change in temperature.

31. • Composites have higher LCTE compared to tooth
structure .with the improvement in the type and
content of filler particles attempt is being made to
reduce LCTE of composites.
• Linear rate of tooth approximately 9-11ppm/ºc. The
LCTE of composites 28-45ppm/ºc. 3-4 times greater
than the tooth structure.

32. • It is a property, which relates to the material’s ability
to resist surface loss due to abrasive forces . Wear
resistance of composites is good , better than GIC,
but less than that of amalgam.
• Factors influencing the wear of the material are:
• Filler content of the composite material
• Occlusal contact relation of the restoration
WEAR RESISTANCE

33. • Location of the restoration on the tooth & the tooth’s
in the arch
• Abrasive effect of food bolus, toothbrush bristles ,
oral prophylaxis method etc.
• Rubbing of tooth contacts interproximally.
• Degree of polymerization of the material

34. WATER ABSORPTION
• It is the material’s ability to absorb water over time.
Resin matrix in composites tends to absorb water
making it swell.
• This leads to reduction in the effectiveness of the
composite material and can also cause filler
debonding and promote diffusion of unbound
monomer . High filler content lowers water
absorption tendency.

35. MECHANICAL PROPERTIES
Macrofilled Microfilled Hybrid Packable Flowable
1 Filler
size(µm)
8-12 0.04-0.4 0.6- 1.0 0.2- 2.0 0.2- 3.0
2 Filler vol% 60-65 20-55 60-65 59-80 42-62
3 Depth of cure _ 5 6.1 5.5 5.6
4 Compressive
strength
(Mpa)
200-300 200-250 250-300 220- 300 203
5 Tensile
strength
_ 24 42 34 34

36. Macrofilled Microfilled Hybrid Packable Flowable
6 Elastic
modulus
8-15 3-6 7-12 9-12 3-6
7 LCTE 25-35 50-60 30-40 _ _
8 Water
sorption
0.5-0.7 1.4-1.7 0.5-0.7 _ _

37. MODULUS OF ELASTICITY
• It is a measure of the stiffness of a material.
• Microfilled composites have low modulus of
elasticity ,hence higher flexibility , whereas hybrid
composites comparatively exhibit more rigidity .
Therefore, microfills are preffered in class v and
hybrids in class I & II.

38. RADIOPACITY
• Radiopacity is an important requirement for esthetic
restorative materials to differentiate the restoration
from radiolucent recurrent caries.
• Quartz and silica fillers used are radiolucent.
Radiopaque fillers like barium / strontium /zirconium
are added for this purpose.

39. COLOUR STABILITY
• It is an important property of an esthetic restorative
material.
• Change of colour can result due to
 Staining
 Water exchange within the polymer matrix and
interaction with unreacted polymer sites
 Stress cracks within the polymer matrix

40. POLYMERIZATION SHRINKAGE
• When the composite material is cured, the monomer
gets converted to polymer and during the process
there occurs polymerization shrinkage in the material.
• It has been observed that during the process of
polymerization , about 55-65% of monomer gets
converted to polymer and the remaining resin does
not polymerize.

41. • It leads to generation of internal stresses within the
polymer chains and at the surface of the restoration
which creates gap formation at the tooth surface
restoration interface causing microleakage.
• The unbonded material present at surface of the
restoration tends to distort trying to accommodate
stress.

42. C - FACTOR
• Configuration factor is the ratio of bonded surfaces of
the restorations to the unbonded surfaces.
• c – factor = bonded surface
unbonded surface
• The significance of this ratio is that higher its value,
greater is the polymerization shrinkage.

44. • The developing polymerization shrinkage in a
composite generate stress on the bonded interface that
are in competition with the developing bond strength
of the setting restorative (Adhesive) to the cavity
surfaces, which may result in (partial) debonding,
marginal leakage and post-operative pain

45. Methods to reduce polymerization shrinkage
• It can be decreased by incrementally adding and
independently curing each increment of the composite
material. The contraction within each small increment is
less, thereby generating less stresses.
• Increasing the filler content of the restorative material.
• Soft start polymerization method helps in reducing
internal stresses instead of high intensity light curing.

46. • The most recent modification on the polymer matrix
is based on using ring opening polymerization of the
silorane molecules, instead of free radical
polymerization of dimethacrylate monomers, which
decreases polymerization shrinkage.
• Preheating composite before photo-activation, which
provides better marginal adaptation and enhances the
flow.
• Angulation of light tip and distance of curing tip also
reduces the polymerization shrinkage.

47. DIFFERENT TYPES OF COMPOSITES

48. TRADITIONAL/ CONVENTIONAL/
MACROFILLED
• It is referred to as macrofilled because of relatively
large size of filler particles.
• These traditional quartz particles were produced by
grinding and milling with a particle size of around 8-
12 microns. It generally contain 75%- 80% inorganic
filler by weight.
• It is extremely hard, difficult to grind and polish, has
the potential abrade opposing tooth structure .

49. Conventional composite have a higher amount of
initial wear at occlusal contact areas than do the
microfill or hybrid types.
Disadvantages
• Due to selective abrasion the hard filler particles are
left elevated producing rough surface.
• They show tendency to discolour due to susceptibility
of rough surface to retain stain.
• Fracture of restoration is another commonly occuring
consequence.
USES:- class II & class IV

50. MICROFILLED COMPOSITES
• Microfilled composites were designed to overcome
the drawbacks of conventional composites, chiefly
being the rough surface characteristics.
• It contained submicron filler particles , approximately
0.01-0.04 µm in size.
• The manufacturing of microfilled composites
involves addition of colloidal silica into the matrix

51. • Untill the composites becomes very viscous. Then it is
polymerized and ground into 5-50µm particles and are
incorporated into non polymerized resin matrix.
• The resin is then filled with micro-filler, but only at
half the conc. Of pre-polymerized resin fillers to
avoid excessive thickening.
• The weakness of these material is that the bond
between these pre-polymerized composite particles
and curable matrix is weak decreasing its strength &
allowing resin filler to be lost at the surface.

52. ADVANTAGES
1. Due to small sized filler particles, they can be
polished to the highest luster and smoothest surface.
Highly finished restoration is less susceptible to
plaque and extrinsic straining.
2. Most esthetic and it has low modulus of elasticity,
hence high flexibility. In class v cavities , this
property allowed the microfilled restorations to flex
during tooth flexure without fracture.

53. DISADVANTAGES
• The bond between resin filler matrix interface is weak
resulting in loss of resin filler from the material’s
surface.
• Low tensile strength
• High water sorption, which softens the resin matrix
decreasing strength.
• High polymerization shrinkage.

54. • Clinical consideration:-
• Moderate stress areas requiring optimal polishability
(class III & V)

55. HYBRID COMPOSITES
• This resin composite is achieved by using
combination of macro and microfillers in the same
material.
• This produced a hybrid category containing a blend
of submicron fillers and small particle fillers.
• They provided improved physical properties due to
high level filler loading made possible because of
wide range of medium and small filler particle sizes.

56. • Ground heavy metal glasses present 75-85 wt%.
• Colloidal silica present approximately 10-20wt%.
Their high filler loading also improves the material’s
resistance to intrinsic discolouration.

57. ADVANTAGES
• Good physical properties
• Improve wear resistance
• Superior surface morphology
• Good esthetics

58. Disadvantages
• Increased surface roughness with time
Clinical consideration
• Anterior & Posterior restoration due to their
superior surface smoothness and good
strength.

59. NANOFILLED COMPOSITE
• These have nanofillers that are 0.005 to 0.01µm in
size.
• These primary particles can be easily agglomerated
allowing a full range of filler sizes.
• This makes possible increased filler loading and a
reduced amount of resin matrix, thereby reducing
shrinkage while providing esthetics and strength.

60. • The main example of nanofilled composites is Filtek
Supreme Plus.
• It can be strengthened by the addition of resin
reinforced fillers with nanofibres.

61. NANO-HYBRID COMPOSITE
• Nano-hybrids comprises of milled glass fillers along
with nano particles in the size range of 40-50nm.
• The smaller size of these particles enables higher
filler loading and the distribution in the resin matrix
and also tends to increase the interfacial area between
the filler & the matrix leading to better dispersion and
reduced polymerization shrinkage.

62. RECENT ADVANCES IN COMPOSITE

63. • The recent advances in composite material can be
grouped as follows:
Direct restoration Indirect restoration
Packable composite Art glass
Flowable Composite Belle glass
Compomer Fibre reinforced composite
Giomer Ceromer
Ormocer
Smart composite
Silorane
Antimicrobial composite
Self healing composite

64. PACKABLE / CONDENSABLE/HIGH
DENSITY COMPOSITE
• These are composite materials having high filler
loading. They were developed with an idea of having
a composite material that has handling characteristics
similar to amalgam.
• Their physical properties include low polymerization
shrinkage, radiopacity, high depth of cure and good
wear resistance.
• The Average filler particle size varies from 0.2 to
20µm

65. • Uses
• They are intended primarily for large posterior
restorations like class I & class II.

66. • They can be easily packed or condensed in a cavity.
• It is easy to establish a good proximal contact.
• The occlusal anatomy of the restoration can be well
shaped.
• Good fracture resistance.
• They can also be used as an underlying support for
larger composite restoration
ADVANTAGES

67. DISADVANTAGES
• They are opaque and unaesthetic materials, therefore
not used for anterior restoration.
• Due to high viscosity, the difference layers are not
properly adapted with each other.
• Presence of dry spots from inadequate resin
saturation, resulting in weak areas.
• They do not completely accomplish handling
properties similar to amalgam.

68. FLOWABLE COMPOSITE
• These are low viscosity, lightly filled composite
material. The particle size of inorganic filler is in he
range of 0.2-3.0µm and filler loading is 42-60% by
volume.
• This materials should be placed in thin layers as they
show high polymerization shrinkage. Placing them in
bulk should be avoided.

69. INDICATION
• As a pit & fissure sealant.
• Restorative for small class I class III and class V
abrasion areas.
• Repair resin for defective margins of composite
restorations and crowns.
• Tunnel restorations
• Luting agent for porcelain / composite veneers.
• A thin veneer over resin modified glass-ionomer as it
bonds well with dried RMGIC, it provide better
colour stability & wear resistance.

70. ADVANTAGES
• Easy to use syringable materials.
• they show high wettability, which allows good
adaptation of the restorative material to the prepared
tooth surfaces
• High flexibility, therefore can be used in areas of
tooth abfraction.
• Different shades
• High depth of cure

71. DISADVANTAGES
• They can no be used in high stress bearing areas due
to low wear resistance & low strength.
• High polymerization shrinkage
• The material fatigues more quickly and breaks more
frequently.
• The material stains easily.

72. COMPOMER (polyacid modified composite
resin)
• The term is an acronym derived from composite and
glass-ionomer.
• Basically compomers are light polymerized
composite resin restoratives, modified to contain ion-
lechable glass particles and anhydrous polyalkenoic
acid. This is why the term polyacid modified
composite.

73. • Compomer monomers contain acidic functional
groups that can participate in an acid/base glass-
ionomer reaction following polymerization of the
resin molecule.
• A resin polymerization takes place with the
compomers after the material has set completely. The
glass-ionomer reaction(acid/base) may then occur in
the presence of water.

74. • In the presence of water from the oral cavity, the acid
functional groups, which are attached to the monomer
units, and have now become part of the polymerized
material are able to react with the base (glass) to
stimulate the glass ionomer reaction. Fluoride is
released as a result of this reaction.

75. PROPERTIES
• Adhesion: for proper adhesion of the restoration to
the tooth surface, acid etching of the tooth needs to be
done. The restorations is retained micromechanically
through resin tags. Acid base reaction for ion-
exchange requires water does not occur for some time
after placement.

76. • Fluoride release: It shows limited fluoride release,
which starts after 2-3 months. It is more than other
comparable glass-ionomer formulations but less than
conventional composite.
• Mechanical properties: inferior to convenional
composite(low stress bearing areas).
• Good strength, biocompatible, low solubility.

77. INDICATIONS:
• Sealing and filling of occlusal pits and fissures.
• Restoration of deciduous teeth.
• Minimal cavity preparation or tunnel preparation
• As a liner
• Core-build up.
• Repair of defective margins in restorations.
• Class V repairs.
• Erosion
• Retrograde filing materials

78. GIOMER
• Giomers as the name suggests are a combination of
glass-ionomer and composites, possessing properties
of both the materials.
• They are resin based materials containing pre reacted
glass –ionomer particles. PRG particles comprise of
fluorosilicate glass, which has been reacted with
polyacrylic acid and then incorporated into the resin.

79. PROPERTIES
• Light activated material.
• Require the use of bonding agent.
• Show excellent esthetics
• Easy polishability
• biocompatibility

80. INDICATION
• Class V abrasion, erosion and abfraction lesions
• Repair of defective margins in restorations.

81. ORMOCER
• Ormocer, the acronym of organically modified
ceramic can be used as a restorative material for both
anterior and posterior teeth.
• It consist of three components – organic portion,
inorganic portion and the polysiloxanes.
• After polymerization, the organic portion of he
methacrylate groups form as 3-dimentionally cross-
linked polymers.

82. • They are synthesized through solution and gelation
process .
• Their coefficient of thermal expansion is very similar
to natural tooth structure.
• These materials were formulated in an attempt to
overcome the problems created by polymerization
shrinkage of conventional composites.
• This class of materials combines the surface
properties of silicons, toughness of organic polymers
& hardness & thermal stability of ceramics.

83. ADVANTAGES
• Low polymerization shrinkage
• High abrasion resistance
• Good biocompatibility
• Provide protection against caries
• Highly esthetic, providing excellent final burnishing.

84. USES
• Direct restoration for all types of cavities
• Cosmetic veneer
• Orthodontic bonding adhesive

85. SILORANE
• It is a resin based composite comprised of two molecules
siloxane and oxirane.
• The siloxane backbone was introduced in order to provide
the most hydrophobic nature, which is important since too
high water sorption limits the long term intraoral physical
strength of the composites
• Oxirane is a cationic ring opening addition
polymerizaiton reaction which stands for their low
shrinkage and low polymerization stress.

86. • The cationic cure starts with the initiation process of
an acidic cation which opens the oxirane ring and
generates a new acidic center, carbocation.
• After the addition to an oxirane monomer , the epoxy
ring is opened to form a chain , or in the case of two-
or multifunctional monomers a network is formed.
• The volumetric shrinkage 0.94-0.99vol%.

87. ADVANTAGES
• Low polymerization shrinkage and stress
• Less microleakage and better marginal integrity
• Less bacterial adhesion
• Less sensitive towards exogenic staining
• Good biocompatibility

88. ANTIBACTERIAL COMPOSITE
• Composites having antimicrobial properties have
been tried by introducing agents like chlorhexidene,
silver or some antibiotics into the material. The
microbes get killed on contact with the material or
through leaching of antimicrobial agents into the oral
cavity.

89. • Silver and titanium particles were introduced.
Silver ions cause structural damage to the bacteria by
direct contact and not by release of ions.
• Advantages
Addition of silver ions caused
• No adverse effect on mechanical properties, strength
• no adverse effect on colour stability
• Good depth of cure

90. • Methacryloxydecyl pyridinium bromide (MDPB)
On polymerization, this monomer gets chemically
bound to the resin matrix becoming part of the
polymer network.
 Advantages
 It has been shown to be effective against streptococci
 No adverse effect seen on the mechanical properties
of BisGMA

91.  Chlorhexidene
• Addition of chlorhexidene was atempted in the
composite resin, but it proved to be unsuccessful.
 Disadvantages
• Its addition caused deterioration of the physical and
mechanical properties of the material
• The released chemical showed toxic effects
• Antibacterial activity was short lived.

92. SMART COMPOSITE
• Ivoclair introduced a material in 1998 named Ariston
pHC (pH control).
• Ariston is an ion releasing composite material, which
releases fluoride, hydroxyl and calcium ions as the
pH drops in the areas immediately adjacent to the
restorative material. This is said to neutralize the acid
and counteract the decalcification of enamel / dentin.

93. • The paste consists of Barium, Aluminium and Fluoride
silicate glass filler (1µm) with Ytterbium trifluoride,
silicon dioxide and alkaline calcium silicate glass in
dimethacrylate monomers.
• Smart composites work based on the newly developed
alkaline glass filler which will reduce secondary caries
formation at the margin of a restoration by inhibiting
bacterial growth. This results in a reduced
demineralization and a buffering of the acid produced by
caries forming microorganisms

94. SELF HEALING COMPOSITE
• Impact damage to composite structures can result in
drastic reduction in mechanical properties.
• Bio-inspired approach is adopted to effect self
healing which can be described as mechanical,
thermal or chemically induced damage that is
automatically repaired by materials already contained
within the structure.

95. • Resin matrix- GRUBB’s catalyst
• Dicyclopentadiene (DCPD) in microcapsules

96. INDIRECT RESIN COMPOSITE

97. • These composites were developed to overcome the
drawbacks of direct resin composites. They are
processed in the laboratory under specialized
conditions of heat/light/pressure to produce a cured
material showing superior physical properties and
lesser polymerization shrinkage.

98. ART GLASS
• It consists of resin matrix of BisGMA/ UDMA and
radiopaque filler of barium glass along with colloidal
silica.
• Art glass is photocured using a special xenon
stroboscopic light having 320-500 nm emission
range.

99.  Advantages
• High wear resistance
• Good marginal adaptation
• Esthetics
• Superior proximal contact
 Uses
Most commonly used in inlays, onlays and crowns

100. Belle glass HP
• It was introduced by Belle de st. Clair in 1996 as
indirect restorative material.
• Its consists of resin matrix of BisGMA and fillers.
• It is polymerized under pressure of 29 psi at temp. of
138ºc in the presence of nitrogen gas.
• The esthetics, wear resistance, polymerizaion rate is
high due to
 High temp. Administered
 Presence of oxygen free enviroment

101. • Ordinarily , oxygen tends to gets entrapped in the
composites and interferes with polymerization
process and also reduces translucency.

102. FIBRE REINFORCED COMPOSITE
Major components: resin matrix and fibers
• Fibers- Ceramic
• Glass
• Carbon
• Alumina
• Silicon nitride
• - Polymer
• KEVLAR (unidirectional)
• HDLPE
Due to translucent appearance of these materials no masking
materials are needed, which allows a thin layer(0.5mm) of
composite to be placed , which is esthetic .

103.  Uses
• Meal-free restorations, which may be inlay, onlay,
crown
• Periodontal splinting or post trauma spilinting
• Fixed bridges
• Implant supported crowns fixed orthodontic retainers
• Repairing dentures

104. Ribbond
Ever stik

105. CEROMER
• Ceromers are a specific combination of the latest in
ceramic filler technology and advanced polymer
chemistry that provide enhanced function and
aesthetics.
• Contains barium glass (< 1 μm), spheroidal mixed
oxide, ytterbium trifluoride, and silicon dioxide (57
vol%) in dimethacrylate monomers (Bis- GMA and
urethane dimethacrylate.
• They exhibit fluoride release lower than conventional
glass-ionomers or compomers.

106. • Indications
• Class I and II posterior restorations (stress bearing
areas)
• Class III and IV anterior restorations
• Class V restorations cervical caries, root erosion,
abfraction, wedge-shaped defects
• Inlays/onlays with extraoral post-tempering

107. GENERAL STEPS IN CLINICAL
PROCEDURE
• While using composite material for restoration, stepwise
clinical technique has to be followed:
• Local anaesthesia
• Preparation of operating site
• Shade selection
• Isolation of operating site
• Assessment of occlusal contacts
• Tooth preparation procedure
• Restorative technique
• Inserting and curing composite
• Design of Incremental technique
• Developing contacts
• Finishing & polishing

108. LOCALANESTHESIA
• This is preferred in most patients as it reduces
apprehension and salivation .
• Administering local anaesthesia makes the patient
relaxed and comfortable thus contributing to better
operative dentistry, especially while placing bonded
restorations.
• It can be omitted in the case preparation is very
shallow.

109. Cleaning and preparing operating site
• It is important that the tooth surface is clean without
having any plaque, pellicle , calculus or stains. This
makes the surface more receptive to bonding , which
is important for the long term success of he
restoration.
• Prophylactic pastes containing flavouring agents,
glycerine or fluorides should be avoided as they may
interfere with acid etching.

110. SHADE SELECTION
While dealing with esthetic restorative materials,
selecting the appropriate shade is an important step.
• Composite shade is selected before placing the rubber
dam, without excessive tooth drying and matched
with clean moist tooth surface.
• Colour of the rubber dam tends to reflect on the tooth
surface and the teeth when subjected to prolonged
drying get dehydrated , which makes them lighter in
shade due to decrease in translucency.

111. • Therefore both are avoided. Also colour of the tooth
is influenced by factors such as thickness ,
translucency & distribution of enamel & dentin,
intrinsic and extrinsic stains, age of the patient,
trauma and root canal treatment.

112. • Many shade guides are available in the market to the
help shade selection
• Universally adopted shade guide is VITA shade
guide. This shade guide first the shades into hues and
then shows hues with increased chroma and
decreased value.
• While making colour selection good lightening is
very important, natural light being a better option.

113. Colour acuity and eye fatigue
• The colour selection should be made as quickly as
possible because the colour receptors of the eye are
unable to distinguish between similar colours after
approximately 30 sec.
• After selection to confirm the shade, a small amount
of the selected shade can be directly placed on the
tooth close to the area to be restored and cured.

114. ISOLATING OF OPERATING SITE
• Composite materials are very sensitive to water
contamination. Contamination of etched tooth
surfaces with oral fluids interferes with bond
formation and also causes degradation of physical
properties of the material.
• Adequate isolation can be achieved by using rubber
dam. It not only achieves adequate access, vision and
moisture control, but also causes retraction of the soft
tissues.

115. ASSESSMENT OF OCCLUSAL CONTACTS
• Preoperative assessment of the occlusal contacts
should be made. It is important to identify occlusal
contacts of the teeth to be restored, mandibular
closure pattern, or any abnormal forces acting. This
can influence the stability of the restoration.

116. TYPES OF TOOTH PREPARATIONS
Tooth preparation designs vary depending on the
clinical situation.
Conventional
Bevelled conventional
Modified
 box-only
Slot preparation

117. CONVENTIONAL DESIGN
• These are typical amalgam cavity preparation designs
with uniform depth , flat floors, butt joint and
retention grooves in dentin. This design is indicated
for cavity preparations on root surfaces and for large
class I & class II composite restoration.

119. BEVELLED CONVENTIONAL
• This tooth preparation design is similar to
conventional but with some bevelled enamel margins.
• Bevelling exposes the ends of the enamel rods ,
which allows them to be more effectively etched than
when only the sides are exposed to acid etchant. Also,
there is an increase in the etched surface area. These
together result in stronger enamel- to-resin bond.
• Bevel is given at an angle of 45º to the cavosurface.

120. Due to such preparation shows:
• Reduced marginal leakage
• Less marginal discoloration
• More retention
• Better esthetic blend of the restoration to the tooth
surface.

121.  INDICATION
• It is indicated when an old amalgam or other
defective restoration, having conventional tooth
preparation design with enamel design with enamel
margin, is to be replaced with composite restoration.
• For class III, IV, V and VI restoration
• For restoring large carious lesion in which there is
anticipation of increased retention and resistance
form.

122.  CONTRAINDICATION
• Bevel are indicated on the proximal margins. Bevels
are not placed on occlusal surfaces of posterior teeth
or other areas of potentially heavy contacts.

123. MODIFIED PREPARATION
• It is an scooped out preparation whose depth and
extent are dependent solely upon that of the carious
lesion.
• There is no specified wall design or axial/pulpal
depth. No uniform dentinal depth is achieved.

124.  INDICATIONS
• Small or moderate sized lesions having enamel
margins.
• For correcting enamel defects.

125. BOX-ONLY
• Box only design involves the formation of box
shaped preparation restricted only to the proximal
surface.
• A proximal box is prepared with either an inverted
cone or round diamond stone held parallel to the long
axis of the tooth & it made to cut through the
marginal ridge in the gingival direction.

126. • The initial proximal axial depth is 0.2mm in the
dentino-enamel junction.
• The extent of the preparation is determined by the
size and depth of the caries.

127. SLOT PREPARATION
• Facial/ lingual slot preparations are restricted to the
proximal surfaces of posterior teeth having assess to
the lesion either from facial/lingual direction.
• Proximal surface lesions, which can be easily
accessed from the facial/ lingual direction instead of
occlusal direction.
• Preparation is mostly made using a round bur. The
initial axial depth is 0.2mm in the dentin enamel
junction. The cavosurface margin are 90º or greater.

129. RESTORATIVE TECHNIQUE
• The steps for the restorative technique are as
follows:
 Etching and bonding
 Matrix & wedge application
 Inserting and curing

130. ETCHING AND BONDING
• The entire cavity preparation including the enamel
margins are etched with 30-40% phosphoric acid. In
case of proximal preparations before etching, the
proximal surface of unprepared tooth is protected by
placing a polyester strip.
• The etchant is applied to all of the prepared tooth
surface and about 0.5mm beyond the prepared
margins onto the unprepared tooth.

131. • The application time for the etchant is 15-30 sec.
• The area is then washed and dried.
• Over drying using an air spray should be avoided.
• With a micro-brush or an applicator tip, the primer
and adhesive are applied as per manufacturer’s
instruction.
• After application , it is lightly dried with an air
syringe to evaporate any solvent like acetone,
alcohol or water followed by polymerization with
light curing.

132. MATRIX AND WEDGE APPLICATION
• Matrix applied to the proximal surface of the
prepared tooth before inserting restoration material. It
serves purpose of:
 Confining the restorative material.
 Assisting in development of appropriate tooth
contours .
 Isolating the tooth preparation.
 Enhancing the effectiveness of enamel /dentin
bonding system.
 Reduces the amount of excess material and minimizes
the finishing time.

133. • For class III : matrix used
The commonly used matrix is pre-contoured clear
polyester strip. The proximal surface of the tooth is
usually convex and the strip is flat, so it is necessary
to shape the strip to conform to tooth contours.
• For class IV :
clear plastic or celluloid crown form
clear polyester strip matrix
• For class II:
tofflemire matrix system

134. Matrix should extend just above (occlusal to) the
marginal ridge and below (gingival to) the gingival
margin.

135. • Types of matrix used in case of composite
restoration :
• Clear polyester matrix with tofflemire retainer
used with light reflecting wedge.
• Ultrathin universal metal (0.001 inch)matrix with
tofflemire retainer .Tofflemire metal matrix with
phototech thinned (0.0005 inch) contact areas.
• Thin sectional metal matrix (0.0015 inch) with
metal rings.
• Customized compound supported sectional metal
matrix.

136. • Wedge is placed into the gingival embrasure and is
positioned between the two adjacent teeth, below the
prepared gingival margin, and exterior to the matrix
material.
• FUNCTIONS
• To seal the gingival margin by pressing the matrix
against the prepared tooth.
• To separate the tooth.
• Protects the inter-proximal gingiva.

137. • Ensures formation of good proximal contact, by
preventing gingival overhang of the restoration.
• The rubber dam and proximal tissues are pushed
proximally to open the gingival embrassure.
•
• Pre-wedging allows greater separation of teeth and
more space to build the contact.

138. INSERTING AND CURING COMPOSITE
• The composite restoration usually is placed in two
stages. First, a bonding adhesive is applied.
• Second, the composite restorative material is inserted.
• Etching and priming the prepared structure and
placing the bonding adhesive should be done
according to manufacturer’s direction.

139. • Composite available are of two types:
Self cured
Light cured

140. • Self cure also referred to as chemically activated
resins or auto cure resin.
• They are marketed in two pastes, one contains the
initiator (benzoyl peroxide) and the other contains
activator (tertiary amine).
• As the two pastes are mixed, amine interacts with the
peroxide to produce free radicals , i.e a compound
with reactive unpaired electron.
• These radicals attack the carbon double bonds in resin
monomer initiating addition polymerization.

141. • Polymerization occurs centre of the material
• Sets within 45 seconds
• No control over working time
• Shrinkage towards centre of bulk
• Air may get incorporated
• More wastage of material
• Not properly finished

142. • Light activated resin are two types
 UV light
 Visible light
in UV activated system, the activator was UV light at
365nm wavelength, which spilt benzoin methyl ether
(initiator) into the free radicals. Due to their
drawbacks, this system was replaced by visible light
activated resins.

143. • In this system visible light at 470nm wavelength is
used as an activator.
• It shows rapid cure.
• On command setting occurs.
• Better colour stability due to aliphatic amine
initiator.

144. • Many studies recommended the use of flowable
composites as the first increment to allow through
adaptation to all areas of cavity preparation.
However, flowable resins show high polymerization
shrinkage.
• To over come this, some authors advocate the use of
‘snow plow technique’.

145. Snow plow technique
• The use of flowable composites in conjunction with
posterior resin composite restorations has been called
the snow-plow technique.
• The technique has demonstrated significantly reduced
void formation compared with placement of
restorative composite alone.
• In this technique an initial increment of flowable
composite is placed over the gingival and pulpal
floors of the cavity preparation.

146. • This layer is not cured at this stage, but rather an
initial increment of heavily filled restorative resin
composite is syringed or pushed into the unset
flowable resin composite.
• This technique is said to show advantages such as:
better marginal adaptation and reduced void
formation.

147. • Injectable composite material is available as
syringes with disposable needles or self contained
compules with syringe tips of various shades.
• The syringe technique has advantages that
i) it provides a convenient means of transporting the
composite to the preparation
ii) reduces the possibility of trapping air.

148. INCREMENTAL LAYERING TECHNIQUE
• When placing posterior composites, the use of small
increments is recommended by many authors for
insertion and polymerization so that the after effect of
shrinkage stress can be reduced.

149. HORIZONTAL LAYERING TECHNIQUE
• The horizontal placement
technique utilizes
composite resin layers,
each layer <2.0 mm thick.
This technique has been
reported to increase the C-
factor, and thereupon
increases the shrinkage
stresses between the
opposing cavity walls.

150. OBLIQUE LAYERING TECHNIQUE
• The oblique technique is
accomplished by placing a
series of wedge-shaped
composite increments. Each
increment is photo cured twice,
first through the cavity walls
and then from the occlusal
surface, to direct the vectors of
polymerization toward the
adhesive surface. This
technique reduces the C-factor
and prevents the distortion of
cavity walls

151. VERTICAL LAYERING TECHNIQUE
• Place small increments in
vertical pattern starting from one
wall, i.e., buccal or lingual and
carried to another wall. Start
polymerization from behind the
wall, i.e., if buccal increment is
placed on the lingual wall, it is
cured from outside of the lingual
wall. This reduces gap at
gingival wall which is formed
due to polymerization shrinkage,
hence postoperative sensitivity
and secondary caries.

152. U-SHAPED LAYERING TECHNIQUE
• First a U- shaped
increment is placed at
the base both occlusally
and gingivally. It is
followed by horizontal
and oblique increments
to fill the preparation.
Curing is done from the
all sides.

153. LIGHT CURING UNITS
• Light curing can be accomplished with
 Quartz-Tungsten-Halogen curing unit
 Plasma arc curing unit
 Laser curing unit
 Light emitting diode curing unit

154. • In order of lowest to highest intensity
• LED lamps
• QTH lamps
• PAC lamps
• Argon laser lamps

155. • The aim of any curing unit is to maximize light
energy in the absorption range of the photoinitiator
present in the composite being cured.
• Most commonly used photo-initiator is
camphoroquinone, which when exposed o 474 nm
wavelength absorbs photos of light energy and
initiates polymerization reaction.

156. QUARTZ-TUNGSTEN-HALOGEN
• Most widely used dental curing light.
• Consists of a quartz bulb with a tungsten filament in a
halogen environment.
• Electric current passes through an extremely thin
tungsten filament which at about 3000ºC produces
Electro Magnetic radiation in the form of visible
light.

157. • Quartz
o encasing structure
o crystalline
o heat resistant
• Tungsten
o filament coil
o flow of electricity
• Halogen gas
o protects filament.
• Power Density: 500-1500mW/cm2

158. • Band-pass filters
• restricts broader light to narrow blue light
400-500 nm
• range of photo-initiators
99.5% of original radiant energy filtered

159. • Advantages:
• Economical.
• Filters used to dissipate heat to the oral structures &
provide restriction of visible light to narrower
spectrum of initiators.
• Disadvantages:
• Diminished light intensity over a period of time
causes degradation of halogen bulb & degradation of
reflector.
• Shorter life about 100 hrs.
• High temperature production.
• Bond strength decreases with increase in distance.

160. PLASMA-ARC (PAC)
• High voltage is generated
between two tungsten
electrodes creating a
spark that ionizes Xenon
creating a conductive gas
known as Plasma.
• These lamps are
characterized by a high
energy output in a narrow
range of wavelength.

161. • Wavelength 400-500 nm.
• Has a highly filtered photosensor which measures
light coming from end of curing tip based on which
microcomputer calculates the time required for
curing.

162. • Advantages:
• High irradiance up to 2400 mW/cm2
• claim 1-3 sec cure.
• Power density of 600-2050 mW/cm2
• Disadvantages:
• Expensive.
• High temperature development.
• Heavy so not portable.
• Requires an in built filter to produce narrow
continuous spectrum.

163. ARGON LASER
• Laser sources emit
monochromatic light at a few
distinct frequencies within the
desired range to initiate
polymerization of composites.
• Argon laser generates one
wavelength of blue light having
a band width of 40-45 nm.

164. • ADVANTAGES:
• Produces narrow focused non divergent
monochromatic light of 490nm.
• Less power utilized.
• Thoroughness and depth of cure is greater. Laser
curing bond strength did not decrease with increasing
distance.
• DISADVANTAGES:
• Risk of other tissues being irradiated.
• Ophthalmic damage of operator and patient.
• Large in size and heavy.
• expensive

165. LIGHT-EMITTING DIODES (LED)
• Combination of two
semiconductors
• n doped & p doped.
• n doped have excess of e- & p
doped have holes.
• When both types are combined
& voltage is applied e- & holes
connect resulting in emission
of light of characteristic
wavelength.

166. • Initially used Silicon
• Carbide electrode.
• When LED of suitable band gap energy is used they
produce only the desired wavelength range.
• Narrow emission spectrum – 400-490 nm
• peak at 470 nm
• near absorption max of camphoroquinone.

167. • Advantages:
• Long service life of more than 100hrs.
• Low temperature development.
• No filter system.
• Low power consumption.
• Wavelength of 400-490nm.
• Disadvantages:
• Photoinitiator is only CQ.
• Requires longer exposure time to adequately
polymerize microfills & hybrid resin.

168. FINISHING & POLISHING
• FINISHING : process of removing surface defects or
scratches created during the contouring process
through the use of cutting or grinding instruments or
both.
• Polishing : process of providing luster or gloss on a
material surface.

169. FLUTED FINISHING BURS
• They are available in 8,12,16,20 30
fluted bur design.
• The fewer the flutes, the more
aggressive is the cutting .
• They are used for finishing composites.
• 30 fluted burs can be used to smooth,
abrade porcelain surfaces before
application of diamond polishing
pastes.
• Several specific group of fluted
finishing burs have been developed for
finishing of composites known as
esthetic trimming burs.

170. FINISHING KIT
• These kits are designed for reducing and finishing
composite fillings, also in interproximal &
subgingival areas. Eg: Sof-Lex discs (3M ESPE)

171. • Rubber wheels, cups and point:
They can be used for initial contouring, smoothing
and finishing depending on the grit. Eg: vivadent
polishing cups and points.
• Proximal finishing strips:
These strips are made of metal or plastic. They are
best suited for enamel disking before cutting a
preparation and finishing a restoration after final
contouring.

172. REFERENCES
• Phillips’: Science of dental materials
• Sturdevant : Art and science of operative dentistry
• Vimal Sikri : Textbook of operative dentistry
• Marzouk : Operative dentistry – moderntheory and
practice
• Craig: Dental marterials
• Charbeneau : Principles & practice of operative dentistry
• Goldstein : Esthetics in dentistry