COMPOSITES RESTORATIVE MATERIAL DENTISTRY

DENTAL COMPOSITES
PRESENTED BY-
Dr. ANSHU SINGHANIA2

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C
O
N
T
E
N
T
S
• INTRODUCTION
• DEFINITION
• HISTORY
• INDICATIONS
• CONTRAINDICATIONS
• ADVANTAGES
• DISADVANTAGES
• CLASSIFICATION
• COMPOSITION
• METHOD OF
POLYMERIZATION
• TYPES OF COMPOSITE
• CURING OF COMPOSITES
• PROPERTIES
• INDIRECT COMPOSITES
• RECENT ADVANCES IN COMPOSITE
• CLINICAL TECHNIQUES
• FINISHING AND POLISHING
• TUNNEL RESTORATION
• SANDWHICH TECHNIQUE
• CONCLUSION
• REFERENCES
S
E
M
I
N
A
R-
II

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INTRODUCTION
As esthetic awareness grows and becomes more important throughout our society, patients demand highly
esthetic restorations. Esthetic restorative materials must blend into the natural dentition by stimulating the
natural tooth in color, translucence, form, and texture yet also have adequate strength and wear characteristics,
good marginal adaptation and sealing, insolubility, and biocompatibility.
These materials must also remain color stable and maintain external tooth morphology to provide a functional,
lasting esthetic restoration.
They best fulfill the requirements of tooth preservation, excellent esthetics, and durability.
Summitt JB, Robbins JW, Hilton TJ, Schwartz RS, Santos JD. Summitt’s Fundamentals of Operative Dentistry: A Contemporary Approach. 4th ed. Hanover Park, IL:
Quintessence Publishing; 2013.

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DEFINITION
 PHILLIPS’ (SKINNER’S)
A compound of two or more distinctly different materials with properties that are superior or
intermediate to those of the individual constituents
•STURDEVANT
In materials and science, word composite refers to a solid formed from two or more distinct
phases that have been combined to produce properties superior to or intermediate to those of
individual constituents.
2. Ritter AV. Sturdevant's Art and Science of Operative Dentistry. 7th ed. St. Louis: Elsevier; 2018.
1. Phillips RW. Skinner's Science of Dental Materials. 9th ed. Philadelphia: Saunders; 1991.

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•During the first half of the twentieth century, silicates were the tooth-colored material of choice for
cavity restoration. In 1956, Bowen developed a new type of composite material.
• Bowen’s main innovations were bisphenol-A glycidyl dimethacrylate (bisGMA), a monomer that
forms a cross-linked matrix that is highly durable, and a surface treatment utilizing an organic silane
compound called a coupling agent to bond the filler particles to the resin matrix.
•Current tooth– colored restorative materials continue to use this technology, but many further
innovations have been introduced since 1962.
HISTORY
Shen C, Rawls HR, Esquivel-Upshaw JF. Phillips' Science of Dental Materials. 13th ed. St. Louis: Elsevier; 2021.

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1955 1956 1980
1962 1970 1972 1976
• M.
Buonocore
• Acid-etch
technique.
• Dr. Bowen
formulated
Bis-GMA
resin.
• Silane coupling
agents
introduced.
• Macrofilled
composites
developed.
• First
photocured
composites
using UV
light.
• Visible light
curing unit
introduced.
• Microfilied
composites
developed.
• Posterior
composites
introduced.
• Hybrid
composites
developed.
• Ist
generation
indirect
composites.

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1991 1996 2005
1997 1998 1999 2002
• Beta quartz
inserts
developed.
• Flowable
composites
developed.
• Ceromer
indirect
composites
developed.
• Packable
composites
introduced.

• Ormocers
developed.
• Ion-releasing
composites
developed .

• Fibre-reinforced
composites
developed.

• Single
crystal-
modified
composites.
• Nanofilled
composites.

• Silorane
composites
by
Weinmann

INDICATIONS
1. Class I, II, III, IV, V and VI restorations
2. Foundations or core buildups
3. Sealants and preventive resin restorations (conservative composite restorations)
4. Esthetic enhancement procedures: Partial veneers, Full veneers, Diastema closures
5. Temporary or provisional restorations
6. Periodontal splinting
7. Luting of indirect esthetic restorations
8. Interim restorations.
Roberson TM, Heymann HO, Swift EJ. Sturdevant's Art and Science of Operative Dentistry. 7th ed. St. Louis, MO: Elsevier; 2018.
12

CONTRAINDICATIONS
1. Access and isolation difficulties.
2. Heavy, abnormal occlusal stresses.
3. Subgingival extensions.
4. Limited operator skill and knowledge.
5. High caries incidence and poor oral hygiene.
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ADVANTAGES
1. Esthetics
2. Conserve tooth structure
3. Low thermal conductivity
4. Universal application
5. Adhesion
6. Command set
7. Can be polished at the same appointment
8. Repairable
14

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DISADVANTAGES
(1)Polymerization shrinkage.
(2)Technique sensitivity
(3)Time consuming and expensive
(4)Difficult to finish and polish
(5)Increased coefficient of thermal expansion.
Ritter AV. Sturdevant's Art and Science of Operative Dentistry. 7th ed. St. Louis: Elsevier; 2018.

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CLASSIFICATION
• Based on filler particle size and distribution (O'BRIEN in 2002)
• Classification of resin based composites and indications for use
• Based on method of polymerization
• Based on the mode of presentation
• Based on use
• Based on their consistency
• Generations of composite resins

Megafilled composites
Macrofilled composites
Midifilled composites
Minifilled composites
Microfilled composites
Nanofilled composites
1. Based on
Filler
Particle
size and
Distributi
on
10-100μm
1-10μm
0.1-1μm
0.01-0.1μm
0.005-0.01μm

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22

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3. BASED ON METHOD OF POLYMERIZATION
1. Self-cured, auto-cured or Chemically cured composites
2. Light cured composites
- Ultraviolet (UV) light-cured composites
- Visible (V) light-cured composites
3. Dual cured composites
4. Staged- curing composites

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Based on the mode of presentation
1. Two paste system
2. Single paste system
3. Powder-liquid system
Based on use
1. Anterior composites
2. Posterior composites
3. Core buildup composites
4. Luting composites

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Based on their consistency
1. Light body composite – Flowable composites
2. Medium body composites – Medium viscosity composites like microfilled, hybrid,
microhybrid composites.
3. Heavy body composites – Packable composites

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4. GENERATIONS OF COMPOSITE RESINS
• FIRST GENERATION COMPOSITES-
Macroceramic reinforcing phases in an appropriate resin matrix, they have the highest surface
roughness.
• SECOND GENERATION COMPOSITES-
With colloidal and micro ceramic phases in continuous phase, they exhibit best surface texture and
wear resistance better than first generation.
• THIRD GENERATION COMPOSITES-
Hybrid composite in which there is combination of macro and micro ceramics as reinforcers, existing
in 75:25 ratio.

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• FOURTH GENERATION COMPOSITES-
Heat cured, irregularly shaped, highly reinforced composite macro particles with a reinforcing phase
of micro ceramics.
• FIFTH GENERATION COMPOSITES-
Hybrid system in which the continuous resin phase is reinforced with micro ceramics and macro
spherical, highly reinforced, heat cured composite particles.
Surface texture and wear of these materials would be comparable to that of second generation and
physical and mechanical properties comparable to that of fourth generation.
• SIXTH GENERATION COMPOSITES-
Hybrid types in which there is the continuous phase is reinforced with a combination of micro colloidal
ceramics and agglomerates of sintered microceramics.
It exhibits least shrinkage.

(ANSVADA No. 27) describes two types and three classes of composites, as shown by the
following:
Type 1: Polymer-based materials suitable for restorations involving occlusal surfaces
Type 2: Other polymer-based materials
Class 1: Self-cured materials
Class 2: Light-cured materials
Group 1 : Energy applied intra-orally
Group 2: Energy applied extra-orally
Class 3: Dual-cured materials
Sakaguchi RL, Ferracane J, Powers JM, editors. Craig's Restorative Dental Materials. 14th ed. St. Louis: Mosby; 2018

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COMPOSITION OF COMPOSITES
The components of composites are:
a. Resin matrix
b. Fillers
c. Coupling agents
d. Coloring agents
Sikri VK. Textbook of Operative Dentistry. 5th ed. New Delhi: CBS Publishers & Distributors; 2024.

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 The initial resin matrix was Bisphenol Glycidyl methacrylate (BisGMA) and urethane
dimethacrylate (UDMA).
 The BiSGMA/UDMA was viscous and blending of filler particles was difficult, so other
matrix were tried having lower viscosity, such as:
 TEGDMA (Triethylene glycol dimethacrylate) The mixture of two of these three resins
provides appropriate viscosity needed for binding of filler particles. BisGMA and
TEGDMA in the ratio of 3:1 is preferred as increase in TEGDMA substantially increases
the polymerization shrinkage.
Resin Matrix

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Inorganic Fillers
 The size of the filler particles vary from composite to composite depending upon the requirements
and needs.
 To ensure acceptable esthetics of composites, the translucency of the filler must be similar to tooth
structure. Mostly glasses have refractive index 1.5 which is comparable to dentin 1.52 and enamel
1.62.

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ii. Silica: Silica has been used as filler in many forms as pure silica, fused silica and colloidal silica.
These silica fillers apart from reinforcing the composite, also help in light scattering and light
transmission. Other fillers such as Tricalcium phosphate and Zirconium dioxide have also been
used.
The routinely used fillers are:
i. Quartz: Quartz is extremely hard and to grind it in finer particles is difficult. These were used
in early composites, which were difficult to polish and even abraded the opposing tooth structure.

Fillers provide:
• Strength
• Rigidity
• Hardness
• Increase in modulus of elasticity
• Decrease in coefficient of
thermal expansion
• Decrease in contraction
32

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Recent composites contain combination of Macro (Barium glass, particle size
0.7–2.0 μm) and micro (Pyrogenic silica, particle size 0.04–0.07 μm) fillers.
These types of fillers provide:
• Better polishing
• Kindness to antagonist tooth
• Good esthetic and chameleon effect

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Silane Coupling Agents
 Provides interfacial bonding between organic matrix and the inorganic filler particle
phases
 Precoated the silica filler particles with mononuclear films of silane coupling
agents.
 Di-functional

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ü One end is capable of bonding to hydroxyl groups, which exist along the surface
of silica particles, and other end is capable of co-polymerizing with double bonds
of monomers in the matrix phase.
ü Organic silanes such as γ-methacryloxy propyl trimethoxy silane are commonly
used as coupling agents.

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Photoinitiator
 Composites are polymerized with the help of light.
 Camphorquinone as photoinitator.
 Absorbs photons of light at 470nm.

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MACROFILL COMPOSITES
 The first type of composites introduced in the early 1960s.
 No longer used in clinical practice.
 Average particle size is approximately 10-20 µm.
 Because of the relatively large size and extreme hardness of the filler particles,
macrofill composites typically exhibit a rough surface texture.

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 This type of surface texture causes the restoration to be more susceptible to
discoloration from extrinsic staining.
 Macrofill composites have a higher amount of initial wear at occlusal contact
areas than do the microfill or hybrid types.

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MICROFILL COMPOSITES
 Replace the rough surface characteristic of conventional composites with a smooth, lustrous
surface similar to tooth enamel.
 Contain colloidal silica particles whose average diameter is 0.01 to 0.04 µm.
 This small particle size results in a smooth, polished surface in the finished restoration that is less
receptive to plaque or extrinsic staining.
 Have an inorganic filler content of approximately 35% to 60% by weight as it cannot be heavily
filled.

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 Less filler than do conventional or hybrid composites, some of their physical and mechanical
characteristics are inferior.
 Are clinically highly wear resistant. Also, their low modulus of elasticity may allow
microfill composite restorations to flex during tooth flexure, better protecting the bonding
interface.
 Their primary indication is for esthetic areas where this luster is required, such as for direct
resin composite veneers.
 There are 2 types of Microfilled composites.

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1. HETEROGENEOUS MICROFILL
o Blend of precured microfill composite with uncured material.
o Precured particles are generated by grinding cured composites 10-20 µm sized powder.
o Chemically bonded to new material
o Finely finished.
2. HOMOGENEOUS MICROFILL
o Unmodified microfills
Restoring Class V cervical lesions or defects in which cervical flexure is significant
(eg. Bruxism, clenching, stressful conditions)

HYBRID COMPOSITES
1. Hybrid composites were developed in an effort to combine the favorable physical
and mechanical properties characteristic of macrofill composites with the smooth
surface typical of the microfill composites.
2. Have an inorganic filler content of approximately 75% to 85% by weight.
3. Smaller average particle size (0.4–1 µm) than that of conventional composites.

5. Can be used for anterior and posterior restorations. The high filler content also
improves the hybrid material’s resistance to internal discoloration.
6. Current versions of hybrid composites also contain ultrasmall nanofillers, resulting in
superior characteristics. These newer versions of hybrid composites are called mini-
nanohybrid composites.
4. Relatively high content of inorganic fillers, the physical and mechanical
characteristics are generally superior to those of conventional composites, hence
called mini-micro composites. Classic versions of hybrid materials exhibit a smooth
“patina-like” surface texture in the finished restoration.

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NANOFILL COMPOSITES
1. Filler particles that are extremely small (0.005–0.01 µm).
2. High filler levels can be generated in the restorative material, which results in good
physical properties and improved esthetics.
3. The small primary particle size also makes nanofills highly polishable. Because of these
qualities, nanofill and nanohybrid composites are the most popular composite restorative
materials in use.
4. These composites have almost universal clinical applicability and are the primary
materials referred to as composites.

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FLOWABLE COMPOSITES
1. Have lower filler content and consequently inferior physical properties such as
lower wear resistance and lower strength compared with the more heavily filled
composites.
2. The filler content is reduced which results in a decrease in viscosity.
3. They serve as liner to absorb the shrinkage/ contraction of the overlying
composite restoration.

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These materials have the following features:
• The filler content is 20–25% less than that of the traditional hybrid composites.
• Because of the lesser amount of fillers loading, the flow is increased.
• Stickiness to the instrument, which makes it difficult to smoothen the material.

The flowable composites are useful as follows:
• As filling materials in low stress areas.
• As pit and fissure sealing and preventive resin
restorations.
• As liners in proximal boxes of class II preparations.
• For repairing porcelain.
• For rebuilding worn contact areas in composite
restorations.
• Tunnel restorations.
• Core build-up.
• Cementing agents for porcelain restorations.
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Reduced compressive
strength
Low elastic modulus
Increased wear
resistance
The
inferior
features
are:

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Flowable composites are generally contra-indicated for class I, II and IV restorations,
because of the relatively high stresses in these areas.
Because they can flow into small crevice defects along restoration margins, some
dentists refer to flowable resins as “dental caulk.”
The properties and clinical uses of flowable composite materials are similar to
those of the so-called compomers, which are hybrids between resin composites
and glass ionomer materials

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PACKABLE COMPOSITES
 Packable/condensable composites are based on the newly
introduced concept, called PRIMM (polymer rigid
inorganic matrix material).
 This system consists of a resin and a ceramic component.
 The filler/ inorganic phase instead of being incorporated into
composites as ground particles is present as a continuous
network/scaffold of ceramic fibers.
 The fibers are composed of alumina and silicon dioxide.
The diameter of the individual ceramic fiber is less than 2.0
μm.

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 The consistency of PRIMM based composites is similar to that of a freshly
triturated mass of silver amalgam.
 The composite is inserted into the prepared cavity by carrying and ejecting from a
carrier whose nozzle is preferably made from/coated with wear resistant teflon
polymer.
 Packable composites present improved properties over conventional ones, like:
• Increased flexural modulus
• Increased resistance to wear
• Non-stickiness

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METHOD OF POLYMERIZATION
POLYMERIZATION
SELF CURED
Require mixing of two
components, a catalyst and a
base which when react to cause
the material to polymerize
LIGHT
CURED
Classic quartz.
Tungsten Halogen light
curing systems.
Plasma arc curing system
Blue LED light curing units.

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CURING OF COMPOSITES
• After the discontinuation of chemically cured composites, various types of lights
have been used to cure composites.
• A light curing unit with a minimal light output of 550 lux is considered
appropriate for dental use.

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García et al Composite resins. A review of the materials and clinical indications. Med Oral Patol Oral Cir Bucal 2006;11:E215-20

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Lehmann A, Nijakowski K et al aimed to determine the
material preferences and analyse the clinical problems
associated with direct composite restorations in a cohort of
dentists.
Authors confirmed that resin-based composites are the most
popular material for direct restoration in many countries.
Although working with this material is difficult and involves
multiple steps, maintaining a dry cavity during bonding, and
material application may affect the therapeutic success and
durability of these restorations. Clinicians need to be attentive
to this issue and be prepared to adapt their decision-making
and consider opting for alternative restorative materials, if
appropriate.
Lehmann A, Nijakowski K et al. Clinical Difficulties Related to Direct Composite Restorations: A Multinational Survey. Int J Dent. 2025; 75(1): 797-806.

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PROPERTIES OF DENTAL COMPOSITES

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DEGREE OF CONVERSION (DC)
1. The DC is a measure of the percentage of carbon-carbon double bonds that have
been converted to single bonds to form a polymeric resin.
2. The higher the DC, the better the strength, wear resistance, and many other
properties essential to resin performance.
Phillips RW. Skinner's Science of Dental Materials. 9th ed. Philadelphia: Saunders; 1991.

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DEGREE OF CONVERSION (DC)
1. The DC is a measure of the percentage of carbon-carbon double bonds that have
been converted to single bonds to form a polymeric resin.
2. The higher the DC, the better the strength, wear resistance, and many other
properties essential to resin performance.

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1. The LCTE is the rate of dimensional change of a material per unit change in
temperature.
2. The closer the LCTE of the material is to the LCTE of enamel, the lower the chance
for creating voids or openings at the junction of the material and the tooth when
temperature changes occur.
3. The LCTE of modern composites is approximately three times that of tooth
structure.
LINEAR COEFFICIENT OF THERMAL EXPANSION
Ritter AV. Sturdevant's Art and Science of Operative Dentistry. 7th ed. St. Louis: Elsevier; 2018

61
WATER SORPTION
1. Water sorption is the amount of water that a material absorbs over time per unit of
surface area or volume.
2. All of the available tooth-colored materials exhibit some water absorption.
3. Materials with higher filler contents exhibit lower water absorption values than
materials with lower filler content.

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WEAR RESISTANCE
1. Wear resistance refers to a material’s ability to resist surface loss as a result of
abrasive contact with opposing tooth structure, restorative material.
2. The filler particle size, shape, and content affect the potential wear of composites
and other tooth-colored restorative materials.
3. The location of the restoration in the dental arch and occlusal contact relationships
also affect the potential wear of these materials.
4. Wear resistance of contemporary composite materials is generally good but not as
resistant as amalgam but the difference is getting smaller.

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SURFACE TEXTURE
1. Surface texture is the smoothness of the surface of the restorative material.
2. The size and composition of the filler particles primarily determine the smoothness
of a restoration, as does the material’s ability to be finished and polished.
3. Although microfill composites historically have offered the smoothest restorative
surface, nanohybrid and nanofill composites also provide surface textures that are
polishable, esthetically satisfying, and compatible with soft tissues.

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RADIOPACITY
1. Esthetic restorative materials must be sufficiently radiopaque so that the
radiolucent image of recurrent caries around or under a restoration can be seen
more easily in a radiograph.
2. Most composites contain radiopaque fillers such as barium glass to make the
material radiopaque.

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MODULUS OF ELASTICITY
1. Modulus of elasticity is the stiffness of a material.
2. A material having a higher modulus is more rigid; conversely, a material with a
lower modulus is more flexible.
3. A microfill composite material with greater flexibility may perform better in
certain Class V restorations than a more rigid hybrid composite.

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4. This is particularly true for Class V restorations in teeth experiencing heavy
occlusal forces, where stress concentrations exist in the cervical area. Such stress
can cause tooth flexure that can disrupt the bonding interface. Using a more
flexible material such as a microfill composite allows the restorations to bend
with the tooth, better protecting the bonding interface.

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SOLUBILITY
1. Solubility is the loss in weight per unit surface area or volume secondary to
dissolution or disintegration of a material in oral fluids, over time, at a given
temperature.
2. Composite materials do not show any clinically relevant solubility.

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Resin composites have several undesirable characteristics that must be overcome to
achieve long-term clinical success. Volumetric shrinkage during polymerization is typically
between 1.5% and 5.0%, which, when the material is placed into a bonded cavity
preparation, generates internal stresses in the composite that create additional stresses
at the bonded tooth-composite interface, potentially leading to marginal defects.
Shrinkage stresses that occur in the early phase of polymerization when the composite
is still relatively fluid are effectively relieved by deformation and flow of the material.
However, stresses occurring later in the process, after the material has acquired
significant rigidity (called gelation), are not relieved by material flow. These residual
stresses may leave the composite weakened and may reduce the adhesion to the tooth.
Summitt’s Fundamentals of Operative Dentistry A Contemporary Approach - 4th Edition
POLYMERIZATION SHRINKAGE

69
These stresses also may cause gap formation at the cavosurface margins, especially
at those with the weakest bonds (usually dentin or cementum). Marginal gaps may
result in microleakage, sensitivity, staining at the margins of the restoration, and
recurrent caries.
There are five primary strategies that can be used to reduce polymerization
shrinkage stress:
The first is to create a relatively thick primed layer with the chosen dentin bonding
agent.
The second strategy is to use a thin liner (0.5 mm) of resin modiied glass ionomer
under the composite resin restoration.
Summitt’s Fundamentals of Operative Dentistry A Contemporary Approach - 4th Edition

70
The third option is to place a thin layer (0.5 mm) of Flowable composite resin as a
liner.
A fourth concept that may be used to reduce shrinkage stress is the use of “soft-start”
polymerization. To prolong the gel phase of the setting reaction of the composite resin
material. The theory is that the longer the setting composite can maintain a gel or
Flowable condition, the better it can distribute the stresses resulting from shrinking .By
the use of ramped lights, pulse curing, or simply holding the curing light some
distance from the material for the initial exposure.
The Final approach to reduce stress is to place the composite resin in increments.

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Another important clinical consideration regarding the effects of polymerization shrinkage is the
configuration factor (C-factor).
The C-factor is the ratio of bonded surfaces to the unbonded, or free, surfaces in a tooth
preparation.
Class IV restoration (one bonded surface and four unbonded surfaces) with a C-factor of 0.25 is at
low risk for adverse polymerization shrinkage effects.
A Class I restoration with a C-factor of 5 (five bonded surfaces, one unbonded surface) is at much
higher risk of bond disruption associated with polymerization shrinkage, particularly along the pulpal
floor.

72
C-Factor : Ratio of bonded to unbounded/free/ surfaces of tooth
preparation
The higher the C-factor, the greater is the potential for bond disruption from polymerization effects.

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C Factor= 5bonded/ 1 unbonded C Factor= 1 bonded/ 5 unbonded

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Incremental layering of composite

77
Schematic signs and symptoms caused by
polymerization shrinkage.

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Guidelines to minimize chances of composite failure:
• Tooth preparation should be kept as small as possible since composite in bulk leads to failure.
• Avoid sharp internal line angles in tooth preparation.
• Deeper preparations should be given base of calcium hydroxide or glass ionomer cement.
• Strict isolation regime is to be followed.
• Avoid inadequate curing, because it leads to hydrolytic breakdown of composites.
• Use small increments, holding each increment with teflon coated instruments.
• Fill proximal box separately and create proper contact areas.
• Composite, especially at beveled areas, should be finished and polished properly

REFERENCES
1. Sikri VK. Textbook of Operative Dentistry. 5th ed. New Delhi: CBS Publishers & Distributors; 2024.
2. Shen C, Rawls HR, Esquivel-Upshaw JF, editors. Phillips' Science of Dental Materials. 13th ed. St. Louis: Elsevier; 2021.
4. Sakaguchi RL, Ferracane J, Powers JM, editors. Craig's Restorative Dental Materials. 14th ed. St. Louis: Mosby; 2018.
5. Lehmann A, Nijakowski K et al. Clinical Difficulties Related to Direct Composite Restorations: A Multinational Survey. Int J Dent.
2025; 75(1): 797-806.
7. Chandrashekar V, Rudrapati L et al. Incremental techniques in direct composite restoration. J Conserv Dent. 2017; 20(6): 386–391.

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INDIRECT COMPOSITES
Agathian R, Manoharan PS et al. Indirect Resin Composite - A Literature Review. J Adv Clin Res. 2021; 8(1): 13-18.

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IRCs are restorations that are fabricated outside the oral cavity. Most of the IRCs are
made on the removable dies of the prepared tooth inside the laboratory. IRCs replace
various restorations. IRC gives an esthetic substitute to ceramic materials for the posterior
tooth.

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CHARACTERISTIC FEATURES OF IRC
POLYMERIZATION SHRINKAGE: Methacrylate is the material which causes
polymerization shrinkage. It results in gap formation and micro leakage of the
restorations. The use of direct composite in the larger posterior restorations remains a
challenge because of the polymerization shrinkage.
Logurecio et al in 2004 and Thonemann et al in 1999 observed that direct composites
could not resist the stresses due to polymerization in margins of enamel free cavities .
Studies have shown that polymerization shrinkage is less in indirect composites when
compared to the direct composite restorations. It is due to the curing mechanisms. It
includes light, heat, pressure which takes place outside the oral cavity.

84
CONTACTS AND CONTOURS: Establishing a correct proximal contour and ensuring a
firm contact with the adjacent tooth in direct restorations is a challenge. Indirect
composite restorations provide excellent proximal contacts and contour since the
fabrication is done outside the oral cavity, which makes it superior from the direct
composites.

85
WEAR: Direct composite restorations exhibit excessive wear in areas of high occlusal
stress. The major cause of clinical failure of the direct restoration was due to poor
wear resistance.
This can be overcome by curing the composite resin extra-orally with the help of
secondary/additional curing using light, pressure, vacuum, heat, inert gas, or a
combination of these methods resulting in a dense well-cured restoration.
Such restorations can be finished and polished better and can then be cemented to the
prepared cavity resulting in a dense well-cured restoration. The physical properties of
such restorations are greatly improved.

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DISADVANTAGES OF IRC RESTORATIONS
Expensive
Increased Tooth reduction: Indirect restorations may require more tooth reduction as
compared to direct composites to create a path of insertion and removal. It is mainly
due to the divergent tooth preparation and other tooth preparation reduction
requirements.
Difficult for alteration: It is difficult to modify or add extrinsic color at the chair side.
Luting: The thin layer of luting resin cement is liable for shrinkage at the tooth–
restoration interface. The luting resin cement which is applied during the luting
procedure is responsible for the polymerization shrinkages.

87
Indications of IRC
1. Laminate veneers.
2. Inlays and onlays.
3. Jacket crowns.
4. Implant supported restorations.
5. Full coverage crowns.
6. Patients with bone loss.
7. Patients with poor periodontal support requiring occlusal coverage.
8. Fiber-reinforced bridges or retainers.
Contraindications of IRC
9. Patients with parafunctional habits.
10.Inability to isolate the working area because luting of irc is technique sensitive.
11.Teeth with heavy wear and tear due to tmj and occlusal disharmony

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Steps of Composite Restoration
The steps involved in restoration of tooth with composite materials include:
1. Preparation of the operative site
2. Shade selection
3. Isolation of the operating site
4. Tooth preparation
5. Acid etching
6. Bonding agent application
7. Insertion of composite material
8. Curing
9. Finishing and Polishing

Preparation of the Operative Site
89
1. Lahari K, Jaidka S, Somani R et al. Composite Restorations. Int J Adv Res. 2019; 7(10): 761-779.

90
Shade selection

91
Isolation of the operating site
RUBBER DAM COTTON ROLL RETRACTION CORD

92
Tooth Preparation
Tooth preparation for a composite restoration includes the following:
• Removing the fault, defect old material or friable tooth structure.
• Creating prepared enamel margins of 90 degree or greater.
• Creating 90 degree cavosurface margins on root surface.

93
Types of Tooth Preparation
The designs of tooth preparations for composites are:
• Conventional
• Beveled conventional
• Modified
• Box only
• Slot preparations

94
Conventional tooth preparation
The primary indication for conventional tooth preparation in composite
restoration are:
1. Preparations located on root surfaces (non-enamel areas).
2. Moderate to large class I and class II restorations.

95
Beveled conventional
The beveled conventional is typically indicated when a composite restoration is
being used to replace an existing restoration exhibiting a conventional tooth
preparation design with enamel margins or to restore a large area.

96
Modified Beveled
It is indicated primarily for the initial restoration of smaller cavitated carious
lesions usually surrounded by enamel and for correcting enamel defects.
Box
This design is indicated when only the proximal surface is faulty with no lesions
present on the occlusal surface.

97
Facial/ Lingual Slot
This is indicated for restoring proximal lesions on posterior teeth.

98
Acid Etching
Etching is defined as the process of increasing the surface reactivity by demineralizing the superficial calcium
layer and thus creating the enamel tags.
Mechanism of Action:
After tooth preparation, smear layer which constitutes hydroxyapatite, altered collagen with an external surface
formed by denatured collagen is formed on the surface of tooth. When an etchant is applied to the tooth surface, it
dissolves the smear layer and penetrates it. There is preferential dissolution of hydroxyapatite crystals from
enamel and dentin that results in microporous surface topography.

99

100
Procedure for Acid Etching time
Cleaning of tooth surface using pumice paste.
Acid etched for 15 seconds.
Rinsed with water for 20 seconds and dried.

101
Bonding Agent Application
• Dentin adhesion relies primarily on the penetration of adhesive monomers into
the filigree of collagen fibres left exposed by acid etching.

102
GENERATIONS OF BONDING AGENTS

104
Fathpour K, Bazazzade A, Mirmohammadi H
(2021) compared microleakage of cervical
restorations using universal bonding and two-step
self-etch adhesive with or without enamel etching
through a dye penetration testing method.
Authors deduced that selective etching of enamel
will decrease enamel microleakage. G-Premio
Bond shows better microleakage results in
comparison to Clearfil SE Bond in dentinal
margins.
Fathpour K, Bazazzade A, Mirmohammadi H. A Comparative Study of Cervical Composite Restorations Microleakage Using Dental Universal
Bonding and Two-step Self-etch Adhesive. J Contemp Dent Pract 2021;22(9):1035–1040.

105
Insertion of Composite Restoration
Composite resins can be inserted in the prepared cavities either in a bulk or
incremental pattern depending on the site of restoration.

Incremental Layering Technique
• Used in medium to large posterior composite restorations to avoid the limitation of depth of
cure.
• This technique is based on polymerization of resin-based composite layers of less than 2 mm
thickness
• It helps to attain good marginal quality
• It prevents deformation of the preparation wall
• It ensures complete polymerization of the resin-based composite
• Incremental layering of dentin and enamel composite
creates layers with high diffusion which allows optimal light
transmission within the restoration, thus increasing esthetics.
CONVENTIONAL INCREMENTAL TECHNIQUES
Chandrasekhar V, Rudrapati L et al. Incremental techniques in direct composite restoration. J Conserv Dent. 2017; 20(6): 386–391.

107
Horizontal Layering Technique:
The horizontal placement technique
utilizes composite resin layers, each <2.0
mm thick. This technique has been
reported to increase the C-factor, and
reduces polymerization shrinkage, better
contour, esthetics and decrease finishing
time.
Oblique layering technique(Z-technique)
• Reduces C-factor
• Enhanced adaptation
• Decreased polymerization shrinkage

108
Place small increments in vertical pattern
starting from one wall, i.e., buccal or lingual
and carried to another wall.
This reduces gap at gingival wall which is
formed due to polymerization shrinkage,
hence postoperative sensitivity and
secondary caries.
Vertical layering technique

110
Curing
The four main types of photopolymerization sources currently available are visible
lights such as
1. Quartz tungsten halogen lamps
2. Plasma arc lamps
3. Argon ion lasers
4. Light emitting diodes.
• Photopolymerization is a technique that uses light (visible or ultraviolet) to initiate and
propagate a polymerization reaction to form a linear or crosslinked polymer structure.

Quartz-tungsten-halogen (QTH) lamps
• Standard Curing units
• Low efficiency compared to heat generations
• Band pass filters required to emit wavelength of 370-550nm.
Shen C, Rawls HR, Esquivel-Upshaw JF, editors. Phillips' Science of Dental Materials. 13th ed. St. Louis: Elsevier; 2021.
To minimize heating, UV and infrared band-pass filters are inserted just before the fiber optic
system.

Orange filters are widely used because they are complementary to blue and absorb blue radiation.
A small fan is employed to dissipate unwanted heat from the filters and reflector.

The halogen bulb usually last for 50 hours and had to be replaced.

112

113
Plasma arc curing (PAC) lamps
PAC lamps use a xenon gas that is ionized to produce a plasma. The high-intensity white light is
filtered to remove heat and to allow blue light (about 400 to 500 nm) to be emitted.
An exposure of 10 seconds from a plasma arc light is equivalent to 40 seconds from a QTH light.
These systems work at wavelengths between 370 nm and 450 nm.
Shen C, Rawls HR, Esquivel-Upshaw JF, editors. Phillips' Science of Dental Materials. 13th ed. St. Louis: Elsevier; 2021.
Advantages:
• Saves
irradiation time

114
Argon laser lamps
Argon laser lamps have the highest intensity and emit blue green light of
activated wavelengths between 450-500nm.
These lamps work within a limited range of wavelengths, do not require filters, and require shorter
exposure times for curing composites. The devices generate little infrared output, so not much heat
is produced.
Because a Laser is a narrow beam of coherent light, no loss of power over distance occurs as in seen
in QTH units. Therefore, Argon laser curing lights are the units of choice for inaccessible areas.

115
Light-emitting diode (LED) lamps
Using a solid-state electronic process, these light sources
emit radiation only in the blue part of the visible
spectrum, between 440 and 480 nm, and do not
require filters.
LEDs require low wattage, can be battery-powered,
generate no heat, and are quiet because a cooling fan is
not needed.
Although they inherently produce the lowest intensity
radiation, the latest versions are more intense and utilize
two or more LED units to both increase intensity and
extend the wavelength range

116
THE TECHNIQUES OF CURING COMPOSITES
Soft Start
Low intensity curing is utilized initially followed by a high intensity curing. Various light
curing units automatically provide one or more soft-start exposure sequences.
Soft-start polymerization is divided into three techniques: STEPPED, RAMPED, AND
PULSE-DELAY.
Stepped: The restoration is initially cured at low intensity to contour and shape the
restoration. It is followed by second exposure to completely cure the finished
restoration.

117
Ramped: In this method, intensity is gradually increased or “ramped up.” The intensity is
increased with time either by bringing the light toward the tooth from a distance or using
a curing light designed to increase in intensity with time.
Pulse Delay: In the pulse-delay method, a series of exposure pulses is used, each
separated by a rest period. An initial exposure of up to 1 J/cm2
is considered to be
most efficient in reducing shrinkage stresses. During the rest period, polymerization
reaction occurs at a reduced rate.

118
High Intensity
High-intensity curing allows for shorter exposure times for a given depth of cure. A depth of 2.0 mm can
be cured in 10 seconds with a Plasma arc light and 5 seconds with an Argon laser-curing light, as
compared with 40 seconds by a Quartz tungsten halogen lamp.
Extra-Oral Curing
Usually, extra-oral curing is used for the fabrication of indirect composite restorations that are
processed in the laboratory. These laboratory photocuring units work with various combinations of light,
heat, pressure, and vacuum to increase the degree of polymerization and wear resistance of
composites.

119
TECHNIQUE AND LAMP MAINTENANCE
1. A curing lamp with a wavelength range strongly overlapping the absorbance range of the
resin photoinitiation system must be selected.
2. Intensity of light decreases with distance to the log scale; therefore, the lamp tip must be
placed and held at the minimal distance possible throughout the exposure interval (20
seconds or more).

120
3. Curing angle is critical, since maximal intensity is delivered perpendicular (90°) to the
resin surface therefore, the lamp tip must be placed and held as close as possible to 90°
throughout the exposure interval.
4. Lamp intensity should be evaluated frequently and adjustments made to ensure
sufficient radiant energy influx (about 16 J/cm2 ) for adequate curing.

SAFETY PRECAUTIONS FOR USING CURING LAMPS
The light emitted by curing units can cause retinal damage if a person looks
directly at the beam for an extended period or even for short periods in the case
of lasers. To avoid such damage, never look directly into the light tip and
minimize observation of the reflected light for longer periods
Protective eyeglasses and various types of shields that filter the light are
available for increased protection for both clinical personnel and patients.

124
FINISHING AND POLISHING OF COMPOSITE
RESTORATIONS
Main objectives of contouring, finishing and polishing of final restoration
are to:
• Attain optimal contour
• Remove excess composite material
• Polish the surface and margins ofthe composite restoration.
Textbook of Operative Dentistry Nisha Garg

127
GIOMERS
•Giomer is hybrid of words “glass ionomers” and “composite”.
•Giomers have properties of both glass ionomers (Fluoride release, fluoride recharge)
and resin composite (excellent esthetics, easy polishability, biocompatibility).
•Characterized by Pre-Reacted Glass-Ionomer (PRG) technology.

• There is a pre reaction of Fluoroalumino silicate glass fillers with Polyacrylic acid, the
reaction produce a glass ionomer which is more stable.
• This phase is called “WET SILICEOUS HYDROGEL”
• This material is freeze dried, milled, treated with silane and then round to produce
PRG fillers, then these glass fillers are added to the resin matrix (GIOMER)

PROPERTIES
- F release and recharge
- Excellent esthetics
- Easy polishability
- Light activated and require use of BONDING
AGENT to adhere to tooth structure
PRG TECHNOLOGY is used in production of two types of
fillers.
• F- PRG : (Fully pre reacted giomers)
e.g., Reactmer (Shofu)
• S-PRG: (Surface pre reacted giomers)
e.g., Beautiful (Shofu)

INDICATIONS
Root caries
Non carious cervical lesions
Class V cervical lesions
Primary tooth caries
CONTRAINDICATIONS
Class I lesions (decrease wear resistance)
Yap & Mok: Surface Finish of a New Hybrid Aesthetic Restorative Material. Operative Dentistry,
2002, 27, 161-166

COMPOMER
• Polyacid modified composite resin
• Provide the combined benefits of composites (the “comp” in their name) and glass ionomers
(“omer”)
• Fluoride release of GIC and durability of composite
• Composition- ion leach able glass, sodium fluoride, polyacid modified monomer
but no water.
• Setting reaction- free radical polymerization reaction
• Do not have the ability to bond to hard tooth tissues
• The delayed (post-cure and post-water-sorption) acid-base reaction is speculative
and probably insignificant.
N. Dorin Ruse. What Is a “Compomer”? J Can Dent Assoc 1999; 65:500-4

• Based on their structure and properties, these materials belong to the class of dental composites.
• Often erroneously referred to as “hybrid glass ionomers”, “light-cured GICs” or “resin-modified glass
ionomers”along with the “genuine” resin-modified GICs.
• The proposed nomenclature for these materials as polyacid-modified composite resins.
N. Dorin Ruse. What Is a “Compomer”? J Can Dent Assoc 1999; 65:500-4

133
Clinical Usage They are preferred in anterior proximal and cervical restorations (Class III or V)
cavities as an alternative to composite and glass ionomer cements.
Disadvantages
• Require use of bonding agent
• Technique sensitive
• Limited fluoride release
• Microleakage more than resin modified
glass ionomers
• Expansion of matrix due to water sorption
• Physical properties decrease with time.
Advantages
• Optimal esthetics
• Easy to handle Easy to polishing
• Easy to place
• Require no mixing
• Bond strength is higher than glass ionomers.
Textbook of Operative Dentistry Nisha garg

134
ORGANICALLY MODIFIED CERAMIC (ORMOCER)
ORMOCER is an organically modified nonmetallic inorganic composite material.
• They are high molecular weight, relatively low viscosity crosslinking molecules and flexible.
• The inorganic network provides abrasion resistance through its glass-like structure and low water.
• Sorption due to its hydrophobicity and low-level polymerization shrinkage is due to large spacing
between crosslinks.
1.Garg N, Garg A. Textbook of Operative Dentistry. 4th ed. New Delhi: Jaypee Brothers Medical Publishers; 2020.
2.Sharma Y. Recent advances in composite resins- an overview. Asian J Biomed Pharmaceut Sci. 2023;13(99):175-179.

135
Indications
1. As a liner of class I and II cavities.
2. Restoration of GV BLACKS class I, II, V cavities.
3. Reconstruction of traumatically damaged anteriors
4. Splinting of loose teeth
5. As a extended fissure sealant
6. Fabrication of composite inlay
7. Core build up
Contraindications
In areas where esthetics is of prime importance.
Sharma Y. Recent advances in composite resins- an overview. Asian J Biomed Pharmaceut Sci. 2023;13(99):175-179.

136
ANTIBACTERIAL COMPOSITES/ION-RELEASING COMPOSITES
In resin composite materials the addition of an antibacterial component can be achieved through
modifications made to the filler particles or the resin matrix.
The strategies that have provided resin composites possessing antibacterial activity can be divided into
two main groups: a released soluble antimicrobial agent, or a stationary non-released antibacterial
agent.
Beyth et al; Antibacterial dental resin composites ; , React. Funct. Polym. (2013)

137
CHLORHEXIDINE
Though chlorhexidine has shown
antibacterial properties but its
addition to composites has been
unsuccessful because of the following
reasons:
• Weakening of the physical
properties of composites.
• Release chemicals which show toxic
affects.
• Temporary antibacterial activity.
METHACRYLOYLOXYDECYL PYRIDINIUM
BROMIDE (MDPB)
Use of methacryloyloxydecyl pyridinium bromide
(MDPB) was recommended by Imazato in 1994.
It has the following features:
•Its antibacterial property remains constant and
permanent.
• It has shown to be effective against
streptococci.
• It does not have adverse effect on the physical
properties of Bis-GMA based composites.
• On polymerization, it forms chemical bond to
the resin matrix, therefore, no release of any
antibacterial component takes place.
Silver
Silver ions cause structural damage to the
bacteria. In these composites, the antibacterial
property is due to direct contact with bacteria
and not because of release of silver ions.

138
SMART COMPOSITE
•It is a light activated alkaline, nano-filled glass restorative material, which releases calcium, fluoride
and hydroxyl ions when intraoral pH values drop below the critical pH of 5.5 and counteract the
demineralization of the tooth surface and help in remineralization.
•The material can be adequately cured in bulk thickness up to 4mm. It is recommended for the
restoration of class I and class II lesions in both primary and permanent teeth.
•Smart composites containing ACP (amorphous calcium phosphate)
•ACP when integrated into in a composite material, will have an extended time release nature to act
as a source for calcium and phosphate which will be useful for preventing caries
Vertika GuptaSmart materials in dentistry: A reviewInternational Journal of Advance Research and Development (Volume3, Issue6)

139
EXPANDING MATRIX RESINS FOR COMPOSITES
•Composites show polymerization shrinkage on curing which can result in marginal leakage,
postoperative sensitivity and secondary caries. Therefore, slight expansion of the composite during
polymerization is desired to reduce these effects.
•For this, Spiro orthocarbonates (SOCs) are added in composites because they expand on
polymerization. Epoxy resins contract 3.4 percent and SOCs expand 3.6 percent. Both are mixed to
achieve desired expansion

140
FIBRE-REINFORCED COMPOSITE
Fiber-reinforced composites (FRCs) are composite materials with three diferent components: the matrix
(continuous phase), the fibers (dispersed phase), and the zone in between (interphase).
FRC materials present high stifness and strength per weight when compared with other structural
materials along with adequate toughness.
Fibre reinforced composite can be classified according to the type of fibre incorporation (glass, carbon
or polyethylene),
the fibre architecture (Mesh, Unidirectional, Weave, Braid, Leno Weave) and
depending on the method of incorporation of fibre.
Aniket Kumar et al. A Review on Fibre Reinforced Composite Resins; Annals of Prosthodontics and Restorative Dentistry, January-March,2016;2(1):
11-16

141
They offer many advantages:
• Non-corrosiveness
• Translucency
• Good bonding properties
• Repair facility
• Facility for both office and laboratory
preparation
Applications in dentistry:
• periodontal splinting
• orthodontic retention
• Fiber reinforced post crowns
• Reinforcement and repair of removable
partial denture
• Repair of fixed partial denture
Textbook of Operative Dentistry - Vimal Sikri - 4th Edition (2016)

142
NANOCOMPOSITE
•When inorganic phases in an organic/inorganic composite become nanosized (range 0.1–100 nm),
they are called nanocomposites.
•Nanofillers are capable of increasing the overall filler level due to their small particlesizes.
•Increase in filler level results in significant reduction of polymerization shrinkage and dramatically
improve the physical properties of nanocomposites.
•Filtek supreme contains nanometric particles (nanomers) and nanoclusters(ncs).
•Premise is a nanohybrid composed of 3 different types of filler components: nonagglomerated
“discrete” silica nanoparticles, prepolymerized fillers (ppf), and barium glass fillers.
•Ceram-x is an ormocer-based, nanoceramiccomposite. Ceram-x contains glass fillers (1.1–1.5 μm) and
methacrylate modified silicon-dioxide-containing nanofiller (10 nm).
Textbook of Operative Dentistry - Vimal Sikri - 4th Edition (2016)

154
INSERTION OF THE COMPOSITE
Instruments Used for Composite Insertion
Hand instruments: Hand instruments used for placing composites are usually made up of coating with
Teflon so as to avoid sticking of composite to the instrument.
Composite gun: Composite gun is made up of plastic. It is commonly used with composite filled
ampules. For use composite ampules are fitted in the gun and the pressure is applied so that composite
comes out from the ampule.
Syringe: Composite syringe usually carries the low viscosity composite which can easily flow through
needle. This technique has advantage of providing an easy way for placement of composite with
decreased chances of air trapping.
Garg N, Garg A. Textbook of Operative Dentistry. 3rd ed. New Delhi: Jaypee Brothers Medical Publishers; 2015.

155
Garg N, Garg A. Textbook of Operative Dentistry. 3rd ed. New Delhi: Jaypee Brothers Medical Publishers; 2015.

156
Irrespective of location of restoration, composites should be placed and polymerized in increments. This
ensures complete polymerization of the whole composite mass and aids in the anatomical build-up of
the restoration.
Each increment should not be more than 2 mm in thickness, because it is difficult to cure and results in
more polymerization shrinkage stress.
Textbook of Operative Dentistry Nisha Garg

158
TUNNEL RESTORATION
Raghu R. Conservative Dentistry. New Delhi: CBS Publishers & Distributors; 2017.

SANDWICH TECHNIQUE
• Developed by McLean
• Also called the LAMINATE or BILARED TECHNIQUE.
• Refers to a laminated restoration using GIC to replace dentin and composite to replace
enamel.
• Combines the most favorable attributes of two restorative materials i.e. translucency,
aesthetics, durability and higher flexural strength of composite resin with good adhesiveness
and anti-cariogenic properties of GIC.
Raghu R. Conservative Dentistry. New Delhi: CBS Publishers & Distributors; 2017.

OPEN SANDWICH
TECHNIQUE
CLOSED SANDWICH
TECHNIQUE

161
CONCLUSION
Composites have accquired a prominent place among the filling materials employed in
direct techniques. Their considerable aesthetic possibilities give to rise to various
therapeutic indications.
Nonetheless it should not be forgotten that they are highly technique sensitive hence
isolation, its correct indication, choice of right composite for each situation , use of proper
bonding procedure and curing are essential for the satisfactory clinical results.

REFERENCES
1. Sikri VK. Textbook of Operative Dentistry. 5th ed. New Delhi: CBS Publishers & Distributors; 2024.
2. Shen C, Rawls HR, Esquivel-Upshaw JF, editors. Phillips' Science of Dental Materials. 13th ed. St. Louis: Elsevier; 2021.
4. Sakaguchi RL, Ferracane J, Powers JM, editors. Craig's Restorative Dental Materials. 14th ed. St. Louis: Mosby; 2018.
5. Lehmann A, Nijakowski K et al. Clinical Difficulties Related to Direct Composite Restorations: A Multinational Survey. Int J Dent. 2025;
75(1): 797-806.
7. Sharma Y. Recent advances in composite resins- an overview. Asian J Biomed Pharmaceut Sci. 2023;13(99):175-179.
8. Chandrashekar V, Rudrapati L et al. Incremental techniques in direct composite restoration. J Conserv Dent. 2017; 20(6): 386–391.
9. Garg N, Garg A. Textbook of Operative Dentistry. 3rd ed. New Delhi: Jaypee Brothers Medical Publishers; 2015.

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