Dental Composites

COMPOSITES
Part I
Dr. Supratim
Tripathi
Guided by Dr. K C
Ponnappa

 PART I
 Introduction
 Classification
 Composition
 Factors that affect light-curing of composites
 Direct posterior composites
 Posterior pit and fissure sealants
 PART II
 Preventive resin restorations,
class I
 Proximal slot and tunnel restorations
 Class II restorations
 Indirect restorations
 Intraoral chairside technique
 Extra oral chairside technique
 Latest advances in composites

 Terminology. A composite is a physical mixture of materials.
 Although "dental composite" or "composite" is the technically correct
term for these materials, various terms have been widely accepted
as well. Composites often have been called composite restorative
materials, filled resins, composite resins, resin composites, resin-
based composites, or filled composites.
 The parts of the mixture generally are chosen with the purpose of
averaging the properties of the parts to achieve intermediate
properties.

 A dental composite is traditionally indicated as a
mixture of silicate glass particles within an acrylic
monomer that is polymerized during the application.
 The silicate particles provide mechanical
reinforcement of the mixture (reinforcing fillers) and
produce light transmission and light scattering that
adds enamel-like translucency to the material.
 It micromechanically interlocks with the etched
surfaces, seals the walls of the preparation, and
copolymerizes with the composite restorative
material that fills the tooth preparation.

CLASSIFICTION
I] Skinners has classified composites based upon
the average particle size as:
Composite Particle Size
i. Traditional composite
(macrofilled)
8-12µm
ii. Small particle-filled
composite
1-5µm
iii. Microfilled composite 0.04-0.4µm
iv. Hybrid composites 0.6-1.0µm

II]. Another classification based on size of
fillers is mentioned by Sturdevant’s
as:(K.Leinfelder)
 1. Megafill composites -Megafillers– quartz, very large size.
 2. Macrofill composites -Macrofillers – 10-100µ.
 3. Midifill composites - Midifillers – 1-10µ.
 4. Minifill composites - Minifillers – 0.1-1µ.
 5. Microfill composites - Microfillers – 0.01-0.1µ.
 6. Nanofill composites - Nanofillers – 0.005-0.01µ.
MEGAFILL MACROFILL MIDIFILL MINIFILL MICROFILL NANOFILL
Not
Shown
Not
Shown

Midi-filler
2 um
Mini-filler
0.6um
Nanofiller
.02 um
Microfiller
.04 um

 The intensity of light striking the composite is inversely
proportional to the distance from the tip of the fiber-optic
bundle of the curing light to the composite surface.
 Distances of 5 to 6 mm often are encountered. At distances
beyond 6 mm for QTH lights, the output may be less than one
third that at the tip.
 Filler particles tend to scatter the light, and darker colorants
tend to absorb the light. Therefore it is generally
recommended that no more than 1.5- to 2-mm increments be
light-cured at a time.

COMPOSITION
 MODERN COMPOSITES CONTAIN NUMBER OF
INGREDIANTS:
 1.RESIN MATRIX : Monomers that are aromatic or
aliphatic diacrylates.
 Most commonly used dimethacrylates in dentistry
are-Bis GMA,urethane dimethacrylate,triethylene
glycol dimetharrylate.
 2.FILLER PARTICLES: These improve the properties
of the matrix material if bonded well and if not bonded
properly they weaken the material.
 These are commonly produced by grinding or milling
quartz.

 3.Coupling agent : These help in the bonding
of the filler particles.
 Most commonly used is methacryloxy
propyltrimethoxy silane,which in its
hydrolysed state bonds to the filler particles
by a double bond as both have sialonol
groups.
 4.Activation initiator system : These are the
free radicals which are activated by chemical
or other energy activation (heat or light)
which results in polymerization.

 5.Inhibitor:These prevent the
spontaneous polymerization of free
radicals and to prevent the chain
propagation of polymerization after
exposure to the light source.
 6.Optical modifiers: Added to match
the appearance of the teeth. Titanium
oxide and aluminum oxide are added
to modify the opacity (.oo1-.007
wt.%).

 Biocompatibility :
 It usually relates to the effects on the pulp from
two aspects:
1- the inherent chemical toxicity
2- marginal leakage
Uncured composite materials at the floor of the
cavity can serve as the reservoir of the
diffusible components that can induce long
term pulpal inflammation .
Micro leakage might cause bacterial invasion,
secondary caries, pulp reaction or both.

 Retinal damage:
 The light emitted by curing units can
cause retinal damage if one looks
directly at the beam for an extended
period.
 To avoid such damage one should avoid
looking directly into the light tip ,and
minimize observation of the reflected
light for longer periods .Protective eye
glasses and various type of shields are
available for increased protection.

FACTORS THAT AFFECT LIGHT-CURING OF
COMPOSITES
 Time
 Intensity
 Temperature
 Light distance
 Resin thickness
 Air inhibition
 Tooth structure
 Composite shade
 Filler type
 Accelerator quantity
 Heat
 Operatory light

EXPOSURE TIME
 Light-cured composites polymerize both during
and after visible light-activation. These two curing
reactions are known as the “light” and “dark”
reactions.
 The light reaction occurs while light from the
curing unit penetrates the composite.
 The dark reaction, also called post-irradiation
polymerization, begins immediately after the
curing light goes off and continues for up to 24
hours, even in total darkness, but most of it occurs
within 10 to 15 minutes post cure

 The minimum curing time for a light reaction for
most composites under a continuous curing mode
is 20 to 40 seconds (using curing units with the
normal 400 mW/cm2 output).
 Over curing is not harmful but does not improve a
material’s properties.

INTENSITY
 The curing intensity of a blue light has been about 400
mW/cm2 for many years. This is the output of most curing
units and is referred to as the “power density.” Problems
occur when the minimum intensity is not achieved.
 There are four common causes of decreased intensity:
(1) as the bulbs in curing lamps age, the intensity of blue light
can decrease,
(2) voltage drops can affect blue light production,
(3) sterilization of curing tips can reduce light transmission, and
(4) filters to increase blue light transmission can degrade.

TEMPERATURE
 Light-cured composites cure less effectively if they
are cold during application than at room
temperature
 Most curing lamps produce heat, which speeds
the curing process
 However, excess heat can result in pulpitis and
pulp death

DISTANCE BETWEEN LIGHT AND RESIN
The ideal distance of the light source from the composite
is 1 mm, with the light source positioned 90 degrees from
the composite surface.

ANGLE AND PATH OF
LIGHT
 As the angle diverges from 90 degrees to the
composite surface, the light energy is reflected
away and penetration is greatly reduced.
 In molar preparations, the marginal ridge of the
adjacent tooth blocks light when placed at an
angle

THICKNESS OF RESIN
 Optimum polymerization occurs at depths  0.5 to 1.0 mm,
owing to the inhibition of air at the surface and the difficulty
with which light penetrates a resin
 At 2 mm40 to 60%
3 mm 34% of the hardness
 Composites should be cured in increments of not more than 1
to 2 mm

AIR INHIBITION
 Oxygen in the air competes with polymerization and inhibits
setting of the resin.
 The undercured layer can vary from 50 to 500 μm, depending
on the reactivity of the photointiators used.
 Unfilled resins should be cured, then covered with an air-
inhibiting gel, such as a thin layer of petroleum jelly, glycerin,
and then re-cured.
 In addition, curing through a matrix increases surface
polymerization because the matrix reduces air inhibition.

CURING THROUGH TOOTH
STRUCTURE
 It is possible to light-cure resin through enamel, but
this technique is just one- to two-thirds as effective
as direct curing and is appropriate only when there
is no alternative
 Such curing is possible through up to 3 mm of
enamel or 0.5 mm of dentin, but the clinician should
double or triple exposure times.
 When light-curing through tooth structure, porcelain
veneers, and other barriers, it is advisable to use a
high-intensity light.

SHADE OF RESIN
 Darker composite shades cure more slowly and
less deeply than lighter shades.
 At a depth of 1 mm, a dark composite shade
achieves just two-thirds of optimum depth of cure
achieved in translucent shades.
 Hence, when esthetics is not critical, the lightest
shade should be used.

TYPE OF FILLER
 Microfilled composites are more difficult to cure
than macrofilled composites, which have larger
quartz and glass fillers.
 More heavily loaded a composite is with larger
inorganic fillers, the more easily the resin cures.
 Extremely high loading can make a composite
opaque, which actually increases the required
duration of exposure.

AMOUNT OF PHOTOINITIATOR
 All photoinitiators deteriorate over time. However, light-
cured composites are more stable than chemically cured
composites
 Some lightcured composites lose about 10% of their
physical properties when stored for 2 years at room
temperature.
 The major cause of decreased shelf life for light-cured
composite is evaporation of critical monomers
 Most autocured composites have an extended shelf life if
kept under refrigeration.

ROOM-LIGHT POLYMERIZATION
 Operatory lighting
Spectrums in the blue range are included to
improve the color selection of dental restoratives,
but it initiates curing
 Incandescent lighting
Low in blue light and provide the longest
composite working time.
 Fluorescent lighting
Shortest working time for light-cured composites,
because it emits a large amount of blue light

IMPROVING WORKING TIME
1. Place the operatory light farther from the
working field. Doubling the distance of
the operatory light from the patient
2. Place an orange filter over the operatory
light.

DIRECT POSTERIOR
COMPOSITES
 The major benefit of a posterior composite is
that it allows the practitioner to place a
conservative initial restoration, one that
preserves considerably more tooth structure
than an amalgam restoration.
 The typical amalgam restoration occupies 25%
of the occlusal surface, whereas the typical
composite restoration occupies 5%.
 Posterior composites generally are indicated for
initial carious lesions in low–stress-bearing
areas.

 Advantages
 Posterior composites can perform well in highly
esthetic and conservative preparations.
 They bond to enamel with an excellent seal and
can hold weakened cusps together.
 They have low thermal conductivity, no
galvanism, and eliminate the possibility of
mercury toxicity.
 In terms of placement, composites have a
shorter setting time, can be polished during the
placement appointment, and are easily repaired.

 Disadvantages
 Posterior composites are susceptible to wear
or breakage, especially in large stress-bearing
restorations .
 They have no caries inhibiting properties
(whereas glass-ionomer materials do), a poor
coefficient of thermal expansion, less stiffness
than other restoratives, and a greater
tendency to fracture than amalgam.
 Placement is technique-sensitive and requires
hands-on training. Restoring with composite
also takes longer than restoring with amalgam.

 Polymerization shrinkage
 Polymerization shrinkage is of critical concern with
posterior restorations because of the potential for
gaps. Composites shrink 1.2 to 4.5% by volume
and 0.2 to 1.9% by linear measure.
 Polymerization forces are generally 2.8 to 7.3
MPa, which is considerably less than the tensile
strength of enamel (20 to 40 MPa).
 Almost all Class II composites leak at the gingival
margin. These spaces are called contraction gaps
and usually occur at the gingival cavosurface
margins, where the enamel is thin.

 Sensitivity
 Postoperative sensitivity is of particular concern with
posterior composite restorations.
 Cuspal strain results from the constant movement of
weakened cusps under function and can result in pain
during chewing as well as enamel crazing near the
gingiva.
 This problem is less severe with smaller composite
restorations.
 Few composites are able to stabilize weakened cusps.
Although large composite restorations show improved
fracture resistance, they do not prevent cuspal
movement.

 Longevity
 An average amalgam and a properly placed
composite last between 5 and 10 years.
Small non– stress-bearing posterior
composites last considerably longer.
 Composites do not perform as well when
used as a replacement for amalgam in large
preparations. Composites should be used in
conservative preparations and mainly kept
out of occlusion.

POSTERIOR PIT AND
FISSURE SEALANTS
 Among the most conservative and
successful of the posterior resin
restorations are the occlusal Sealants
 There is strong evidence that
sealants without microleakage arrest
any carious activity under them.

Preparation and
placement Isolation
 Tooth isolation is key to achieving a well-
sealed restoration. The dam provides good
isolation of the occlusal surfaces, avoids
patient aspiration of objects, and aids in
evaluation.
 Sealant preparations
 Studies show that acid etching solutions are
unable to penetrate the deeper recesses of
pits and fissures, and that debris also remains
in these areas .

 Etchants
 Generally speaking, gels are as effective as liquid
etchants, providing the gel has access. In deep pits and
fissures, a clinician must carefully verify the
completeness of an etch.
 Sealant repairs
 Repairing sealants that have become worn improves
their integrity. If a portion of sealant is lost, the tooth can
be rebonded . In some studies, reapplication has twice
the success rate of first-time placement.
 Types of materials available
 Both autocured and light-cured sealants are available.
The light-cured sealants give a clinician more time for
placement and cure more rapidly.

 Restorative treatment: light-cured
sealants
 Clinical studies show that when light-
cured sealants are cured for only 20
seconds (which is half the advisable
time but is recommended by many
manufacturers), their retention rate is
lower than that of autocured sealants.

 Procedure for placement of
sealant
 Step 1. Place a rubber dam
or slit dam to isolate the teeth
to be treated.
 Step 2. Teeth with heavy
debris and plaque should be
cleaned
 Step 3. Use a small round
bur (eg, fissure bur or 1/4-
round) to remove any organic
stain in deep grooves and
fissures.
 Step 4. Etch deciduous teeth
for 15 to 30 seconds, primary
teeth for up to 2 minutes (until
frosty) in the usual fashion.

 Step 5. Trace grooves with
an explorer to ensure air
bubbles are not preventing the
etchant from reaching the
deepest grooved areas.
 Step 6. Wash for at least 15
seconds. If the pits and
fissures are unusually deep,
rinse longer (30 s).
 Step 7. Dry using a warm air
dryer, high-speed vacuum, or
an air syringe (in that order of
preference) for a minimum of
15 seconds.

 Step 8. Place unfilled sealants
using a manufacturer’s
applicator, brush, explorer, or ball
burnisher.
 Step 9. Trace the sealant
through the grooves with an
explorer to remove entrapped air
bubbles.
 Step 10. For unfilled sealants,
remove the excess with a dry
cotton pellet
 Step 11. Cure light-activated
sealants for at least 40 seconds.
 Step 12. Check the occlusion.
Adjustments are usually
necessary when using a filled
sealant.

PREVENTIVE RESIN
RESTORATIONS,
CLASS I
 A Class I posterior composite
preparation should be conservative and
affect only enamel whenever possible.
 Tooth structure is removed only to gain
access to and eliminate decay.
 There is no extension for prevention:
any preventive procedure should be
done with an occlusal sealant and
should not involve removal of sound
tooth structure.

 The preparation should affect dentin only when caries is
present. When deep caries is removed, a durable base
or liner should be placed (eg, a glassionomer liner) prior
to placement of composite.
 Teeth with larger caries, involving extensive removal of
enamel, should be restored with a heavily filled
composite resin
 Restorative treatment, Class I
 The occlusal outline of a posterior composite restoration
does not have the form of an amalgam preparation.
There are major differences in depth, width, and extents.
Only carious enamel and dentin are removed in
composite preparations.

 A posterior composite preparation should extend into dentin
only when required for caries removal.
 To clean tight grooves, cut a preparation half the thickness
of enamel.
 To remove caries in enamel, cut the preparation to the width
of a composite syringe tip or condenser tip so the
preparation can be easily filled.
 The most common in smaller preparations is a 90-degree
cavosurface margin that is beveled to expose the enamel
rod ends.
 Such exposure improves bonding and ensures an optimal
seal. The horizontal component of this design helps maintain
the seal that may be lost during composite polymerization.

 Large restorations on worn teeth do not expose
many rod ends, so a beveled preparation is
recommended.
 With larger preparations, the use of an adhesive
enamel exit conserves unsupported enamel by
rounding the tooth and etching three sides
 When using this design, a clinician should be
careful to remove any decay that might remain
under the unsupported enamel.

Procedure for preventive
resin restoration
 Step 1. Place a rubber dam or
slit dam to isolate the teeth that
will be treated.
 Step 2. Apply caries indicator .
Rinse with water for 10
seconds. Reexamine tooth to
detect decay.
 Step 3. Use a small spoon to
remove any stained (decayed)
areas .
 Step 4. Restain, wash, and re-
check tooth to ensure all decay
has been removed .
 Step 5. Acid etch the tooth for
30 seconds, rinse with water for
10 seconds, dry thoroughly with
an air syringe, and examine

 Step 6. Apply bonding
agent according to
manufacturer’s directions .
 Step 7. Place composite.
Light-cure for 40 seconds .
 Step 8. Apply sealant to
cover the restored surface .
Light-cure for 40 seconds.
 Step 9. Remove rubber
dam (or slit dam). Check
occlusion with articulating
paper . Adjust occlusion as
necessary with a fine
diamond or white stone.

PROXIMAL SLOT AND
TUNNEL RESTORATIONS
 Proximal slot restoration means using facial
access to remove interproximal decay in a
posterior tooth.
 Proximal slot preparations are the right choice
when carious lesions are below the contact point
and the caries is clinically visible and accessible.
 These direct access preparations preserve the
occlusal surface and marginal ridge rather than
removing them, as would be the case with a
conventional preparation.
 The marginal ridge is a critical portion of tooth
structure, and its removal often results in loss of
contour and weakened cusps.

 Tunnel preparations
 A tunnel preparation removes proximal
caries through an occlusal access while
leaving the marginal ridge intact.
 This preparation has been refined and is
commonly employed by replacing the
carious dentin with a glass ionomer and
the occlusal enamel portion with a
composite.

 Although the tunnel concept is simple, the
preparation is difficult because it is so
conservative.
 Access and visibility are limited, and anatomic
landmarks are unclear (eg, knowing where the
lesion is buccolingually or occlusogingivally
while trying to reserve the marginal ridge), and
there is risk of pulpal or periodontal ligament
exposure.
 It is important to have a fluoride releasing
material at the proximal opening. Restore the
outer stress-bearing enamel portion of the
access opening with a wear-resistant composite.

 Indications
 Incipient proximal lesions.
 Staining with a disclosing solution, such as 1%
acid red in an ethylene glycol base differentiates
infected carious dentin that should be removed
(ie, infected dentin that is completely denatured
and bacterially invaded) from affected carious
dentin.
 Affected dentin should be left since the protein
matrix remains intact and remineralization from
the ionomer is near certain.
 A good caries detector only stains infected
dentin.

 Restorative treatment
 Use a bite-wing radiograph to determine the location and extent
of caries.
 With an explorer, determine whether the carious defect can be
reached from the facial or lingual surface. If one or the other is
possible, use a facial or lingual proximal slot access and
preserve the occlusal surface.
 If a tunnel preparation is indicated, use a periodontal probe to
measure the depth of the lesion on a bitewing radiograph

CLASS II RESTORATIONS
 Highly conservative preparations are possible when restoring
Class II lesions with composite. When replacing an existing
Class II amalgam restoration with a composite, the only
alteration required in the preparation is to change the enamel
cavosurface margins from 90 degrees to a 45-degree bevel
that is 0.5-mm wide. This change improves enamel– resin
bonding.
 Preparation
 Make a conservative box preparation with rounded line angles.
Make a 45- to 90-degree exit angle to expose enamel rod ends
for bonding.
 Bevels greatly improve but do not eliminate marginal leakage.

 The composite preparation is more
conservative than the amalgam
preparation and that the composite
preparation does not break the
proximal contact. Depth should be just
enough to remove decay.

 The gingival floor of a composite should be slightly
beveled, whereas the amalgam preparation exits
at 90 degrees.
 Extensions should be minimal.
 Natural tooth contacts should remain whenever
possible.
 Retention is achieved by acid etching.
Mechanical retention is unnecessary.
 Round both external and internal line angles to
facilitate placement and adaptation of the
composite

 Liner
 Protect any exposed dentin with a
suitable liner (glass-ionomer liner,
CaOH or polycarboxylate cement).
 Remove liner that may be covering
enamel that needs to be etched, and
complete the preparation. When the
gingival floor is below the
cementoenamel junction, place the
ionomer liner over the entire gingival
floor .

 Placement
 The proximal contact must be
established at the matrix stage. Use a
thin, dead soft metal matrix and a
suitable wedge, or a conventional
amalgam matrix.
 Maximum tooth separation must be
achieved prior to resin placement to
ensure proximal contacts.

 Finishing
 Use fine-grit conventional diamonds for
gross reduction and micron diamonds or
white stones for final shaping and
contouring on the occlusal.
 Use flexible discs on exposed proximal
margins and finishing strips for
interproximal and other inaccessible
areas.

 Teeth also can be restored using indirect
techniques, in which restorations are fabricated
outside of the mouth. Most indirect restorations
are made on a replica of the prepared tooth in a
dental laboratory by a trained technician.
 Tooth-colored indirect systems include
laboratory-processed composites or ceramics
such as porcelain fired on refractory dies or hot
pressed glasses.
 I NDICATIONS
 Esthetics
 Large defects or previous restorations
 Economic factors

 CONTRAINDICATIONS
 Heavy occlusal forces
 Inability to maintain a dry field
 Deep subgingival preparations
 ADVANTAGES
 Improved physical properties
 Ability to strengthen remaining tooth structure
 More precise control of contours and contacts
 Biocompatibility and good tissue response
 Increased auxiliary support

 DISADVANTAGES
 Increased cost and time
 Technique sensitivity
 Wear of opposing dentition and
restorations
 Resin-to-resin bonding difficulties
 Short clinical track record
 Low potential for repair
 Difficult intraoral polishing

 Care should be taken to avoid the
bonding of the temporary material to
the preparation at this phase of the
procedure.
 A lubricant of some sort may be
applied to the preparation if desired,
especially if a resin-based material
was used to block out undercuts and
level the walls of the preparation.

Prepared teeth. Vinyl polysiloxane is injected into an alginate impression.
Fabrication of the composite resin inlay Composite resin inlay is light cured
Enamel margins are etched with 37% phosphoric acid gel.

Mixing of the dual-cured luting
composite resin surface surface of the inlay
Dentin primer is applied Bonding resin is applied to the internal
Luting composite resin is light cured
visible light source
.
Excess luting composite resin is removed
-a brush dipped in bonding agent.

 COMMON PROBLEMS AND SOLUTIONS
 The most common cause of failure of tooth-colored
inlays and onlays is bulk fracture. If bulk fracture
occurs, replacement of the restoration is almost
always Indicated
 REPAIR OF TOOTH-COLORED INLAYS AND
ONLAYS
 Minor defects in indirect composite and ceramic
restorations can be repaired with relative ease.
 For both composite and ceramic inlays, the repair
procedure is initiated by mechanical roughening of
the involved surface.
 While a coarse diamond may be used, a better
result is obtained with the use of air-abrading or
grit-blasting with aluminum oxide particles and a
special intraoral device.

Intraoral chairside technique
1-1 Pre-operative radiograph
shows an upper first bicuspid with
a fractured amalgam and
extensive recurrent caries.
1-2 Initial clinical view showing
the extent of recurrent caries.
1-3 The finished preparation was lubricated
with a water-soluble separator and is shown
with a BiTine ring in place. The opacious
dentin shade of a microhybrid composite
(EsthetoX, Denstply) was used as the initial
increment. This was followed by incremental
placement and light-activation of the regular
body and translucent enamel shades.
1-4 The occlusal and proximal surfaces of the
restoration were anatomically finished. A
tight proximal contact could be seen on
removal of the matrix band.

1-5 The inlay was removed for post-
curing. A methacrylate surfactant was
applied to the gently sandblasted seating
surface of the composite inlay to
enhance its bonding with the resin
cement.
1-6 The cavity was total-etched with a
matrix band in place to facilitate
subsequent cleanup of the polymerized
resin cement in the interproximal area.
1-7 Following final occlusal
adjustment, the polished
restoration and cavity margins
were sealed with a filled
composite surface sealant.
1-8 Post-operative radiograph
showing the completed inlay
restoration.

Extra oral chairside
technique
-Pre-operative micrograph
shows a lower first molar
with extensive interproximal
caries and an anticipated
pulpal exposure.
-Initial clinical view shows
lateral spread of carious
dentin that involves
substantial undermining of
buccal and lingual enamel.
-Pulp horns were exposed
after complete caries
removal. Undercuts were
present along proximal
cavity walls.
-Direct pulp capping using
a calcium hydroxide lining
material.

-Finished inlay preparation
with undercuts blocked by a
resin-modified glass
ionomer cement.
-A vinyl polysiloxane
impression of the inlay
preparation that was
lubricated with a silicone
mold release aerosol to
facilitate separation of the
addition silicone die
material.
-The working flexible die
model was made with a high
durometer die silicone
(Mach-2, Parkell), using a
quick-setting, high viscosity
VPS material (Blu-Mousse,
Parkell) as a base.
-The inlay was fabricated
using a chairside
microhybrid composite
system (Esthet•X,
Denstply). Interproximal
contouring and surface
characterization are more
easily accomplished with
the extraoral chairside
technique.

-Clinical view of the
complete restoration.
-Post-operative radiograph
of the completed
restoration.

Latest advances in
composites
 Advances in Monomer Systems
 Ormocers
 Compomers
 Giomer
 Ceromers
 Smart composites
 Remineralizing resin composites
 Composites with expanding monomers
 Composites with anticariogenic materials

 Stimuli response materials /
Smart materials
 Stimuli response materials possess properties that
may be considerably changed in a controlled
fashion by external stimuli. Such stimuli may be
for example changes of temperature, mechanical
stress, pH, moisture, or electric or magnetic fields.
 Stimuli responsive dental composites may be
quite useful for example for “release-on-
command” of antimicrobial compounds or fluoride
to fight microbes or secondary caries,
respectively.

 Advances in Monomer
Systems
 1. Nonshrinking monomer system
 2. Hydrophobic monomer system
 3. Anti-cariogenic and antimicrobial
monomer system
 4. High-strength, high-conversion
monomer system

 Ormocers:stand for organically modified ceramics
 Ormocer was formulated in an attempt to overcome the
problems created by the polymerization shrinkage of
conventional composites because the coefficient of thermal
expansion is very similar to natural tooth structure.
 Composition
 1.organic polymers-matrix phase
-ceramic polysiloxane
2.inorganic unit glass –inorganic phase
-glasses and ceramics
3.inorganic –organic unit-interfacial phase
-polysiloxanes

 The ORMOCER-based composites are
an innovative variation of traditional
composites with organic matrices and do
not differ from these in their practical
application by the dentist.

 Compomers:
 These are defined as polyacid modified
resins
 “Compomers” are recently introduced
products marketed as a new class of dental
materials. These materials are said to
provide the combined benefits of composites
(the “comp” in their name) and glass
ionomers (“omer”).
 Compomers offer good strength
,biocompatibilty and low solubility.They have
higher wear resistance than composites and
low flouride release than gic

COMPOSITION
 Two main constituents :
Dimethacrylate monomer (s)
Two carboxylic groups
Filler .
 No water
 Ion-leachable glass is partially silanized to
ensure some bonding with the matrix.

Giomer
 GIOMER is basically a modified GLASS
IONOMER.
 It is a true hybrid of two compounds, Glass
Ionomer and Composite
 The difference of Giomer from Compomer is, in
Compomer variable amount of unhydrated
polyacrylic acid is added to the resin matrix and
the acid base reaction wont takes place until water
comes and contact with compomer

 COMPOSITION Of GIOMER (BEAUTIFUL)
 Bisphenol A glycidyl dimethacrylate,
 TEGDMA,
 inorganic glass filler,
 aluminuoxide, silica,
 pre-reacted glass ionomer filler,
 DL-camphorquinone

This phase is called”WET SILICEOUS
HYDROGEL”
PRG TECHNOLOGY is used in production
of two types of fillers.
They are:
S-PRG (Surface Pre Reacted Glass
Ionomer) marketed as BEAUTIFUL (shofu)
F-PRG (Full Pre Reacted Glass Ionomer)
marketed as REACTMER (shofu)

 Ceromers :
 The term stands for ceramic optimized
polymer.
 It is an advanced composite which
utilizes combinations of ceramic fillers to
provide unique handling ,wear and
esthetic properties.
 The properties of ceromers are same as
those of composites and they exhibit
fluoride release lower than conventional
glass ionomers and composites.

 This material consists of a paste containing
barium glass (< 1 µm), spheroidal mixed oxide,
ytterbium trifluoride, and silicon dioxide (57 vol%)
in dimethacrylate monomers (Bis-GMA and
urethane dimethacrylate.
 The properties of the ceromers are identical to
those of composites and they exhibit fluoride
release lower than conventional glass-ionomers or
compomers.

 Nanocomposites
 Nanoparticle filled composites exhibit outstanding
esthetics, are easy to polish and posses an
enhanced wear resistance.
 Nanoparticle fillers may include colloidal silica or
Ormocers, such as in Ceram X from Dentsply.
Similar particles may be used in resin-based
bonding systems.
 Nanoparticle filled dental composites show an
enhanced fracture toughness and adhesion to
tooth tissue.

 Smart composites:
 These class of materials was introduced
by Ariston phc is an ion releasing
composite materials .
 It release ions like flouride ,hydroxyl,and
calcium ions as the ph drops in the area
adjacent to restorative material.
 The paste consists of ba ,al and f
silicate glass filler with utterbium
triflouride ,silican dioxide and alkaline
ca.silicate glass.

 Self-repairing materials
 One of the first self-repairing synthetic materials reported,
interestingly shows some similarities to resin-based dental
materials, since it is resin based. This was an epoxy system
which contained resin filled microcapsules. If a crack occurs
in the epoxy composite material, some of the microcapsules
are destroyed near the crack and release the resin.
 Healing efficiencies of over 90% have been achieved for in
situ samples with a healing chemistry that uses benzylidene-
bis(tricyclohexylphosphine)dichlororuthenium (Grubbs'
catalyst) to initiate ring-opening metathesis polymerization
(ROMP) of the endo isomer of dicyclopentadiene (DCPD;
Brown et al. 2002).

 Remineralizing resin
composites:
 Flouride are currently used to remineralize
non cavitated lesion.These new materials
contain amorphous calcium phosphate
(acp).
 Acp composites will respond to changes in
the oral environment caused by bacterial
plaque or acidic foods to release calcium
and phosphate.
 At low ph during the caries activity the
material transforms from ACP to HAC

 Composites with expanding monomers:
 Composites containing Spiroorthocarbonates,were
introduced in 1970 but were not successfully
commercialized.
 Recently there has been a strong interest in oxirane
and polyol monomers as a method of designing
controlled shrinkage composites.
 The use of spiro orthocarbonates as a component in
dental resin composites resulted in a nearly volume
neutral polymerization and in a doubling of the
adhesive strength of the resin to etched enamel
compared with a control.

 Composites with
anticariogenic materials:
 Imzate developed an antibacterial
monomer , to be added to dental
resins.
 In the absence of the ability of an
adequate marginal seal ,resin
composites and adhesives containing
and adhesives containing
antibacterial agents may prove to be
an important addition.

Dental Composites

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