1.Direct and indirect restorative material
2.Fiber Reinforced composite posts
4.Core build up in post endodontic restorations
5.Pit and fissure sealants
6.Bonding of orthodontic brackets
7.Splinting of mobile teeth
•Activator-Initiator-Soft moldable material hard durable mass
•Pigments-Matching tooth color
•Inhibitor- storage time, working time in chemically activated
•UV Absorbers- Color stability
Most widely used
MOST RECENTLY USED ARE THE SILORANE
• POLYMERIZATION SHRINKAGE
• CROSS LINKING INCREASED – IMPROVED PROPERTIES
BUT DUE TO HIGH DENSITY THESE MONOMERS ARE VISCOUS AND
DIFFICULT TO MANIPULATE
TEGDMA(Dilutent monomer) + BISGMA(Viscous) Decreases Viscosity
easy to manipulate and paste like consistency
IMPROVE THE MECHANICAL PROPERTIES
DECREASE POLYMERIZATION SHRINKAGE
DECREASE THERMAL EXPANSION AND
DECREASE WATER SORPTION
•Very hard and difficult to grind
•Difficult to polish
•Abrades opposing tooth
•Less harder than quartz
•Non crystalline structure
GLASSES WITH HEAVY METALS:
•Slowly leach out
FLOURIDE RELEASING FILLERS:
•Ability to release flourides
•Ytterbium triflouride and Ba-Al-
Effect of filler size and distribution
The COMPOSITE properties are IMPROVED to a
great extent by increasing the filler loading.
This can be achieved by PARTICLES SIZE and
PARTICLES SIZE IN REFERENCE TO WAVELENGTH OF VISIBLE
•These bond the filler particles to the matrix
•They improve properties of resin by transferring stresses
from plastic resin matrix to stiff filler particles
•Organosilanes are most commonly used coupling agents
•Gamma methacryloxypropyl trimethoxysilane
1.Extend storage life
2.Increase working time
BUTYLATED HYDROXYTOULENE 0.01 WT%
TO ACHIEVE NATURAL TOOTH LIKE APPEARANCE
AS LIGHT IS
TO 0.007 WT%)
Darker shades and greater opacities have decreased depth of curing so
we should either increase exposure time or apply thinner layers of
material while curing
Convenience and simplicity Mixing causes air entrapment
leading to porosity which might
weaken the material and
Long term storage stability Aromatic amine accelerators
Oxidize and turn yellow with
time i.e color instability
Manipulation of working/Setting
time by varying proportions
Difficult to mix evenly
Degree of cure equal through
out if mixed properly
Marginal stress build up during
curing is much lower than for
photocured due to slower cross
LIGHT CURING/PHOTOCHEMICALLY ACTIVATED
UV LIGHT CURED VISIBLE LIGHT CURED
UV LIGHT CURED:
LIMITED PENETRATION OF LIGHT INTO RESIN.
LACK OF PENETRATION THROUGH TOOTH STRUCTURE
CAUSED DAMAGE TO RETINA
FACTORS INVOLVED IN PHOTO
DEPTH OF CURE
•Hand held devices which contain the light source and have a rigid light guide made
up of fused optical fibers.
•The most widely used light source is QUARTZ bulb with a Tungsten filament in a
•Four types of lamps are used:
1.Light emitting Diode lamps (LED)
2.Quartz-tungsten-halogen (QTH) lamps
3.Plasma arc curing lamps (PAC)
4.Argon laser lamps
These light sources emit radiation only in the blue part of the visible spectrum between
440 and 480 nm
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.
Produce lowest intensity radiation
The latest versions utilize two or more LED units to increase intensity and extend
Quartz-tungsten-Halogen (QTH) lamps
QTH lamps have a quartz bulb with a tungsten filament that irradiates both UV and
Must be filtered to remove heat and all wavelengths except those in the violet blue
range (~450 to 500 nm)
Intensity diminishes with use.
Plasma arc curing (PAC) lamps
Use ionized xenon gas to produce plasma
High intensity white light is filtered to remove heat
Blue light is then emitted (400-500nm)
Emit at a single wavlength
Emit wavelength of 490nm.
DEPTH OF CURE AND EXPOSURE TIME
•Amount of photons absorbed by initiator depends on
•For maximum curing radiant energy influx should be 16,000 mJ/cm2
• Light absorbtion and scattering in resin composites reduce the degree of
conversion and depth of penetration so exposure time should be increased.
•Curing depth should be kept 2-3mm
•Exposure time depends on the intensity of curing units.
•Higher the intensity lesser will be the exposure time
•Light attenuation varies for different composites so manufacturers instructions
should be followed.
To maximize the degree of polymerization and clinical durablity clinician should
adjust curing time and curing technique to intensity of light source.
Light is also absorbed and scattered as it passes through tooth
structure especially dentin ,causing incomplete curing so in
critical areas like proximal box so here the exposure time must
be increased to compensate for reduction in light intensity
•Light emiitted by curing units can cause retinal damage.
•Never look directly into light tip and reflected light for longer periods
•Wear protective eye glasses and shields that filter light both for operator and
A curing lamp with wavelength matching the absorbance range of
photoinitaiator must be selected.
Critical concentration of free radicals must be formed to initiate
Intensity decreases with distance so lamp tip must be placed at minimum
distance through out exposure interval
Curing angle should be 90 degrees to resin surface to deliver maximum
Lamp intensity should be evaluated frequently.
Combination of light cure and self cure composites
dual-cure resins are commercially available and consist of two light-
One paste contains benzoyl peroxide and other contains aromatic
Chemical curing occurs by mixing the pastes and is accelerated on
command with the light source
light curing is promoted by the amine/CQ combination
and chemical curing is promoted by the amine/BP interaction.
Dual-cure materials are intended for any situation that does not allow
sufficient light penetration to produce adequate monomer conversion, for
example, cementation of bulky ceramic inlays.
•Complete curing throughout is the advantage
CLASSIFICATION OF COMPOSITES:
I. Classification given by Skinner:
Traditional or conventional composites
Small particle filled composites
1-5 . m
0-04 –0.9 . m.
0.6-1 . m
II Philips and Lutz classification:
According to the mean particles size of the major fillers –
Traditional composite resins: (5.30 m earlier, 1.5m
Hybrid composite resins: (1.5 m. earlier, 0.05-0.1m.
Homogeneous microfilled composites: 0.05-0.1 .m
Heterogeneous micro filled composites: 0.05-01, 1-25
III Classifications based on inorganic loading:
a. Heavy filled materials – 75% of inorganic loading by wt
b .Lightly filled material –66% of inorganic loading by wt.
IV. Based on method of curing
1. Chemical cured
2. Light cured
3. Heat cured
4. Dual cured
V Classification based on area used
VI.GENERATIONS OF COMPOSITE RESTORATION
A. First Generation composites
•Consist of macro-ceramic reinforcing phase.
•Has good mechanical properties.
•Highest surface roughness
B. Second Generation composites
•Consists of colloidal and micro-ceramic silica.
•Unfavourable coefficient of thermal expansion
•Wear resistance better than first generation
•Best surface texture.
C. Third Generation composites
•Hybrid composite[combination of macro and micro
•Good surface smoothness and reasonable strength
D. Fourth Generation composites
•Hybrid composite (heat-cured, irregularly shaped, highly
reinforced composite macro-particles with micro (colloidal)
•Comparatively better surface characteristics and
E. Fifth Generation composites:
•Hybrid composite (heat-cured, spherical, highly reinforced
composite macro. particles with micro (colloidal) ceramics].
•Surface texture and wear is similar to second generation
•Physical and mechanical properties similar to fourth
F. Sixth Generation composites:
•Hybrid composite [agglomerates of sintered
•micro (colloidal) ceramics and micro-ceramics]
•Highest percentage of reinforcing particles
•Best mechanical properties
•Wear and surface texture similar to fourth generation
•Least polymerization shrinkage
VII. Classification according to Bayne and
Category Particle size
Macrofillers 10-100 m
Small/fine fillers 0.1-10 m
Microfillers 0.01 – 0.1 m (agglomerated)
Nanofillers 005 - 0.1 m
Conventional or macrofilled composites.
The traditional composites have comparatively large filler
This category was developed during the 1970
The most commonly used filler for these materials is finely
ground amorphous silica and quartz.
Although the average size is 8 to 12 μm, particles as large
as 50 μm may also be present.
Filler loading generally is 70 to 80 wt% or 60 to 70 vol%
Poor wear resistance
Poor marginal integrity
Finishing produces a roughened surface
Discoloration due to rough textured surface to retain stain.
To improve surface smoothness and retain or improve the
physical and mechanical properties of traditional composites
inorganic fillers are ground to a size range of 0.1 to 10μm.
•Fillers were made by grinding quartz to small particle size smaller
Small-particle-filled (SPF) composites generally contain more
inorganic filler (80 to 90 wt% and 65 to 77 vol%) than traditional
High strength and high hardness
Class 1 and class 2 restorations
Agglomerates of 0.01 to 0.1 um inorganic colloidal silica
The problems of surface roughening and low translucency
associated with traditional and small particle composites can be
over come through the use of colloidal silica particles as the
0.04 um or 40nm
2 % wt
PRECURED RESIN FILLER + MONOMER + SILANE TREATED COLLOIDAL
SILICA = HETROGENOUS COMPOSITE
•Inorganic filler loading is increased by
•Weak bonding between precured resin
particles and matrix
•Decreased mechanical properties
•Not suitable for stress bearing areas
They should be finished with diamond burs rather than
carbide burs as they are very much prone to chipping
•Material of choice for smooth surface lesions like class 3
and class 5
1. Splintered prepolymerized particle
2. Spherical prepolymerized particle
3. Agglomerated prepolymerized particle
This category of composite materials was developed in an
effort to obtain even better surface smoothness than that
provided by the large particle composites, while still
maintaining the desirable properties.
Hybrid composites contain two kinds of filler particles:
Most modern hybrid fillers consist of:
2.Ground particles of glasses containing heavy metals.
Constituting a filler content of approximately 75 to 80 wt%
The glasses have an average particle size of about 0.4 to 1.0
Colloidal silica represents 10 to 20 wt% of the total filler
The mechanical properties inferior to those SPF composites
Surface smoothness + good strength Anterior
restorations,including Class IV sites.
• High stress areas where aesthetics dominates
• Nanofillers are the filler particles.
• These particles are extremely small (0.005-0.01
nm) and virtually invisible
• Their particle size is below range of wavelength of
light and thus they do not absorb or scatter
• Aggregates are silane treated
• Additionally the extremely small size of nanofillers allow the
particles to fit into spaces between other particles in
composite and effectively increase the overall filler level.
• Nanofiller permit overall filler level of 80 wt% that
significantly reduce the effect of polymerisation shrinkage and
dramatically improves physical properties
• Commercially available nanocomposites:Filtek supreme plus
Tetric N Ceram
•Like conventional hybrids in range of size of nano fillers
•Mechanical properties like conventional hybrids
•Aesthetics and polishiblity like microfilled composites
•They can be used for both anterior and posterior restorations
•Stronger than nanocomposites
A modifications of the SPF and hybrid composites.
The reduced filler makes them more susceptible to wear, but
improves the clinician’s ability to form a well adapted cavity
base or liner, especially in Class II posterior preparations and
other situations in which access is difficult.
Called dental caulk,as it can flow into small crevices along
Sealing gingival floor of the proximal box of Class II restorations.
Class V cavities.
Small Class III cavities.
First increment of all deep restorations to prevent voids and porosities and
to get good seal.
Small Class I cavities frequently referred to as ‘Preventive Resin
Blocking out cavity undercuts during inlay, onlay and crown preparations
• Decreased microleakage
• Increased marginal adaptation
• High curing shrinkage
• Decreased mechanical properties
• Cannot be used in large restorations because of decrease wear resistance
•Because of the highly plastic, paste like consistency in the precured state,
composites cannot be packed vertically into a cavity in such a way that the
material flows laterally as well as vertically to ensure intimate contact with
the cavity walls.
•This can be explained in terms of class 2 cavity
•Compared with amalgam, the technique of composite placement is far
more time consuming and demanding.
• A solution to this problem is offered by resin composites with filler
characteristics that increase the strength and stiffness of the uncured
material and that provide a consistency similar to that of lathe-cut
•Elongated, fibrous, filler particles of about 100 μm in length
•RoughTextured surfaces and branched geometry tend to inter lock and
• This causes the uncured resin to be stiff and resistant to slumping,yet
moldable under the force of amalgam Condensing instruments (“Plugger”)
1.WORKING TIME AND SETTING TIME
Chemical cured composites:
Setting time:3-5 minutes
Working time:from start of mix till temperature
begins to rise
Light cured composites:
Curing is considered on demand
Composite may appear to be fully hard and
cured after curing by light source,but curing
reaction continues for 24 hours.
Degree of conversion is 75 %
Premature polymerization can occur with 60-
90 seconds of exposure to the ambient light.
Degree of conversion/Degree of cure /Degree of
monomer to polymer conversion
•Percentage of carbon carbon double bonds
converted to single bonds during curing to form a
•Higher the DC greater is the strength,wear and
A conversion of 50 % Bis-GMA means 50 % of polymer have
This does not mean remaining 40-50 % monomer is left in
resin because one of the two methacrylates group of Bis-
GMA may form covalent bonds with polymer forming a
Conversion of monomer to polymer depends on
several factors like:
2.Transmission of light through material
3.Concentration of Sensitizer,initiator and
5.Absorbtion through composite
6.Scattering through composite
The normal range of curing shrinkage is 1.5
to 4 vol % 24 hours after curing
Composites with a high filler loading shrink
Chemically activated have a slow curing than
light cure resins which allows the shrinkage
stresses to relax
3.POLYMERIZATION SHRINKAGE STRESS
Stresses may break
The polymerization shrinkage and stress
1.Total vol of composite
2.Type of composite
REDUCTION OF RESIDUAL STRESSES
The internal pores in chemically cured resins
act to relax residual stresses that build up
The slower curing rate of chemical activation
allows a portion of the shrinkage to be
compensated by internal flow among
developing polymer chains before formation of
After the gel point ,stresses cannot be
relieved but instead continue to increase and
concentrate within the resin and the tooth
structure adjacent to the bonded interfaces.
Approaches to overcome the problem of
1)reduction in volume contracton by altering
the chemistry and or composition of the resin
2) clinical techniques designed to offset the
effects of polymerization shrinkage
1.Incremental build up and cavity configuration
CONFIGURATION FACTOR (C-Factor)
• Is the ratio between the bonded surface areas of a resin
based composite restoration to the non-bonded or free
• Bonded surface/non bonded surface = C factor
• Residual polymerization stresses increases directly with this ratio.
• During curing, shrinkage leaves the bonded cavity surfaces in a state of stresses
• The non bonded ,free surfaces release some of the stresses by contracting
inwards towards the bulk of material
• A layering technique in which the restoration,is build up in increments ,curing one
layer at a time efficiently reduces polymerization stresses by minimizing the c
• The thinner layer lower the bonded surface and maximize the non bonded
• This technique overcomes the limited depth cure and residual stress
• Adds to time and difficulty in placing restoration
2.Soft start,ramp curing and delayed curing
Photo-polymerization stress buildup
inspired by chemical initiation by
providing an initial low rate of
polymerization thereby extending the
available time for stress relaxation before
reaching gel point .
In this technique curing begins with a low
intensity and finishes with high intensity
Ramped curing and delayed curing
Variations of soft start
The intensity is gradually increased or
ramped up during exposure.
Consist of either stepwise, linear or
Delay allows substantial stress relaxation to
The longer the time period available for
relaxation the lower the residual stresses.
Delayed and exponential ramp curing appear to
provide the greater reduction in curing stress.
Intensity of the curing lamps must be
considered in such situations as
exposure time and curing are related to
the intensity of the lamps.
4.COEFFICIENT OF THERMAL EXPANSION
Linear coefficient of thermal expansion of
composite ranges between 25-30 x 10-6 /℃ and
55-68 x 10-6 /℃
Large differences between CTE of tooth and
composite causes expansion and contraction
resulting in stress
Filler loading is the only way to reduce the CTE.
Water sorption may occur when:
1.Material may have a high solublity rate.
2.Resin may contain voids
3.Hydrolytic breakdown of the bonds between
fillers and resin
Water sorption can decrement the longetivity of
Inadequate light intensity and duration
especially in deeper areas causes incomplete
polymerization and increased solublity.
ADA specifies solublity should be less than or
equal to 7.5 µg/mm
Higher values lead to reduce wear and abrasion
Radio opacity is to check the integrity of resin
Radio opacity can be provided by glass
ceramics with heavy metals like Ba,Sr and Zr
Not chemically inert
Esthetics is the major factor for use of
Discolouration can be;
1. Marginal discolouration
May occur due to:
1.Improper adaptation of material to cavity
2.Breakage of interfacial bonds between resin
Related to surface roughness of the composite.
Seen in composites with larger filler sizes.
Debris gets entrapped between the spaces and
cannot be removed by routine brushing.
Dark pitted discolouration may be seen due to
exposure of air void when composite wears away.
3. Bulk discolouration
Seen in chemically activated resin mainly
Chemical degradation of components and
absorbtion of fluids from oral enviroment
Composites show loss of surface contour of composite
restorations in the mouth
Abrasive wear from chewing and tooth brushing
Erosive wear from degradation of the composite in the oral
Wear of posterior composite restorations is observed at the
contact area,where stresses are the highest.
Interproximal wear has also been observed.
Ditching at the margins within the composite is observed for
posterior composites,resulting from inadequate bonding and
Packable composites have better wear resistance than micro
filled or flowable composites
Two types of wear seen in composites:
2 body wear
3 body wear
Factors causing wear:
2.Degree of polymerization
It is usually related to the effects on pulp from two
1. Inherent chemical toxicity of material
2. The marginal leakage of the fluids
•Pulp can be affected if chemicals leach out from the composites.
•Inadequately cured composites at floor of cavity act as a
reservoir of diffusable components that can induce long term
•This is for concern in case of light cure.
•If clinician attempts to cure a thick segment or inadequate
exposure the uncured material can leach out constituents
adjacent to the pulp.
•Adequately polymerized resins leach out in very small amounts
which cannot cause toxicity.
Inherent chemical toxicity of material
• The shrinkage of composite during polymerization and the
subsequent marginal leakage is a well known phenomenon
• The marginal leakage might allow bacterial growth and the
microorganisms may cause secondary caries or pulpal
• Therefore ,the restorative procedure must be designed to
minimize polymerization shrinkage and marginal leakage
The marginal leakage of the fluids
• Bisphenol A (BPA), a precursor of BiSGMA has been
shown to be a xenoestrogen ,or a compound found
in environment that mimics the effects of estrogen
by having affinity for estrogen receptors
• BPA has been shown to cause reproductive
anomalies especially in development stages of fetal
• Controversy surrounds this issue because it is unclear
how much BPA or BPA-DM is released to the oral cavity
and what dosage is enough to affect human health.
•Gic liners are applied as pulp protection in deep cavities
•Zincoxide eugenol is contraindiated as it interferes with
1.Preparation of operating site
8.Insertion,prepolymerization contouring and
1.Calculus removal with proper instruments
2.Cleaning operting site with pumice slurry
Create a site more receptive for bonding
Prophy paste containing flavouring agent,glycerine
or flouride act as contaminants and conflict with
acid etch technique.
Shade of the tooth should be selected before isolation
Shade should be selected without prolonged drying the tooth
Composite materials are available in:
Good lighting should be present for proper color selection
1.Operator should hold shade tab near the tooth to determine natural
2.Shade tab should be partially covered with operators thumb or patients
lip – natural effect of shadows
3.The selection of shade should be done in natural light
4.The selection should be made rapidly
5.Final shade can be verified by patient with a mirror
6.Bleaching if done should be done before any restoration placement
The shade selected should be placed directly on the
tooth close to area to be restored and cured
Objectives in tooth preparation:
Extent is determined by size, shape, and location of defect
Remove all Caries, any fault, defective, old friable tooth structure.
Removal of discolored tooth structure as required for esthetics.
Create prepared enamel margin of 90° or greater by giving bevel
Create 90° cavosurface on root surfaces
Extend from periphery to sound tooth structure
Preparation should be done in most conservative way as possible
Micromechanical retention by etching of enamel and dentin.
Dentinal retention groove
Beveling provides increased surface area of etching
Gradual transition between composite and tooth
Bevels of 45 degrees should be given:
1-2mm wide facially
0.5mm other areas
Bevels should be prepared with medium grit diamond burs
Bevels should be avoided in:
Class 1 restorations
Class 2 restorations
Cervical margins with thin enamel
Primarily by micromechanical bonding
May be improved by:
• Flat preparation floors
• Floors perpendicular to occlusal forces
• Boxlike forms
Similar to that of cavity preparation for amalgam restoration.
A uniform depth of the cavity
90° cavosurface margin is required
1. Moderate to large class I and class II restorations
2. Preparation is located on root surfaces.
3. Old amalgam restoration being replaced
• Similar to conventional cavity design
• Have some beveled enamel margins.
1. Composite is used to replace existing restoration.
(class III, IV, V)
2. Restore large area
Rarely used for posterior composite restorations
• All parameters determined by extent of caries.
• Conserve tooth and obtain retention (MICRO
• No specified wall configuration.
• No Specified pulpal or axial depth.
• Scooped out appearance
• small,cavitated,carious lesion surrounded by enamel
• correcting enamel defects.
•When only Proximal surface is faulty and no lesion on occlusal surface
•Extent is determined by caries
FACIAL OR LINGUAL SLOT
1. Lesion is proximal but access is made through
facial or lingual surface
2. Cavosurface is 90 or greater.
3. Direct access for removal of caries.
Isolation can be accomplished by rubber dams,cotton rolls
Retraction cords can be used for subgingival extensions
Contamination with saliva leads to decreased bond strength
Acid may be grouped as:
Minerals (phosphoric acid,nitric acid)
Organic (maleic acid,citric acid)
Polymeric(e.g polyacrylic acid)
Most frequently used acid is 37% phosphoric acid
Available as: Gel or liquid form
Applied by brush or directly through syringe
15-20 seconds etching time
Primary teeth or young teeth with mind flourosis require longer etching time
Freshly cut enamel etches faster
Clinically the most important parameter of proper etched
tooth is presence of a frosty white appearance on tooth
Clean tooth and isolate
Place mylar strip to
protect adjacent tooth
Place etchant liquid/gel
Wash for 10 sec
longer if gel used
Over drying must be avoided if dentin invloved as it may
result in collapse of collagen mesh which results in
forming a dense film and prevents bonding agent to
A thin layer of resin between conditioned dentin and resin
matrix of resin composite restorative material.
Restorative resin are hydrophobic and tooth is are hydrophillic
so bonding agent should have both parts.
The hydrophillic part bonds with calcium in hydroxyappatite
crystals or collagen and hydrophobic component bonds with
selectively dissolves tooth structure to provide retention for restoration
Bridge to connect tooth to adhesive
hydrophillic monomers in a solvent like alcohol,ethanol or water
Penetrate moist tooth structure especially dentin and collagen mesh and
EG:HEMA(2-hydroxylethyl methacrylate,4-MET(methacryloxyethyl trimelletic
Hydrophobic monomers + small amount hydrophillic monomer
Used in combination with primers to form effective bond to tooth structure.
Adhesive bonds resin to primer
Primerpenetrates tooth and completes binding sequence
Eg: hydrophobic dimethacrylates like Bis-GMA with small amount of
hydrophillic monomers like HEMA
Remove all debris and remove
Isolate tooth from saliva
Saturate microbrush with
Apply with gentle rubbing
Use gentle air pressure to
remove excess acetone and
Cure for 20 seconds
Good contour Occlusion smoothness
Finishing—Process of removing surface defects or scratches created during the
contouring process through the use of cutting or grinding instruments or both.
Remove all unattatched bonding agent with bard parker blade no
12,composite resin knife or gold foil finishing instrument.
Finishing burs,diamonds,,micron diamonds,burs,rubber point and disks are
used to create surface texture,lobes and ridges
Polishing cups and polishing paste are used for lusture
Metal or plastic finishing strips interproximally
Polishing—Process of providing luster or gloss on a material surface.
Removal of surface irregularites and achieving smoothest possible
Polishing can be
Aggressive use of disks may be avoided
Polishing paste can be used for 15-30 seconds using rubber cup
moistened with water
Microfilled composites can be polished with disks
Small particle hybrids can be polished with fine diamonds,flexible
disks and very fine polishing paste
Dry polishing:should be resrved only for microfilled
composites.The heat from the disks produces highly
durable,smear layer of resin over microfill
Polyester using carbonate (-O-CO-O-)
Connects methacrylate ends to the central section of monomer.
packable like amalgam
photocurable in bulk
curable without generating high residual shrinkage stress.
High molecular weight
Long rigid central section
Flexible methacrylate end groups
Reduced curing shrinkage
Enhanced monomer to polymer conversion
Bulky space-filling dimethacrylate monomer
Bulky three-ring central group provides steric hindrance
Which holds the monomers apart
slows the rate of polymerization
Dimethacrylate with a Bulky, Space-Filling Central Group
Dimer dicarbamate dimethacrylate (DDCDMA)
Bulky central group:
6-carbon aliphatic ring
two long hydrocarbon side chains
Center section is connected to two methacrylate end groups via urethane
Greater stress relaxation
reduced water absorption
High-Molecular-Weight Phase-Separating Dicarbamate
with Hydrophobic Side Chains
chemistry based on epoxy, rather than acrylic functionality.
tetra-functional “silorane” monomers
Silorane chemistry utilizes a combination of epoxy functionality
three-unit ring with two carbons and an oxygen
combined with siloxane units
Reduced polymerization shrinkage
Silorane” Ring-Opening Tetrafunctional Epoxy
Organically Modified Ceramic Oligomers
Ormocer is an acronym for organically modified ceramics.
molecule-sized hybrid structures
Reduced polymerization shrinkage,
low water sorption
very high biocompatibility
Polyhedral Oligomeric Silsesquioxane (POSS)
12-sided silicate cages
silane and functionalized to copolymerize with other monomers.
molecule-sized hybrid organic-inorganic oligomeric compound
“Artiste Nano-Hybrid Composite” (Pentron Clinical, Wallingford, CT).
Excellent polish retention,
Good mechanical properties
Good wear resistance.
Patient's demands for aesthetics, phenomenal developments in the resin and filler
technologies, advance in nanotechnology and clinical training in their use has made
composite resins a material of choice for direct restorative purposes. The wide range of
colours,shades,translucencies,opacities,flouroscence,tones,viscosity etc available with
present generations of composite resins have enabled clinicians to provide a restoration
that mimics natural tooth structure and optimizes function as well.
Further research is always an ongoing process to reduce or eliminate drawbacks of