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Ideal esthetic material for conservative
restorations has resulted in improvements
in materials and techniques.
To improve the physical characteristics of
the esthetic materials, they develop a polymeric dental restorative material reinforced with silica particles (1962) generally termed composites.
History
Composites are presently the most popular tooth-colored materials and with acid etch technique (1952) represent major advances.
Filled (composite) resin restorative materials are all basically two-phase systems.
Dispersed phase of Continuous phasehigh strength of polymericceramic particles matrix Inorganic filler Organic resin matrix
Silane coupling agent
Composition
Quartz, borosilicate glass
Lithium aluminum silicate
Inorganic Filler
Barium aluminum silicate
Strontium or zinc glass
Reduce the coefficient of thermal expansion.
Provide higher strength , stiffness , FX. resistance
thermal dimension change.
InorganInorganic Filleric Filler
Reduce the polymerization shrinkage.Reduce the polymerization shrinkage.
Translucency matching tooth Translucency matching tooth structure.structure.
Chemical inert nessChemical inert ness
Opaque to x-ray toOpaque to x-ray to helphelp making making a post operative diagnosis a post operative diagnosis
(radiopacity).(radiopacity).
Most material contain Most material contain 70-80 70-80 percent filler by weight. percent filler by weight.
• Mixing chemically reactive polymeric materials.
• After insertion continuous ductile phase to bind dispersed filler particles together.
• This ductile resin act as a medium to transfer the stress b/w the particles (prevent distortion of the
material).• The resin systems are highly cross-
linked , aromatic dimethacrylates. (BisGMA) diluted with less viscous co monomers , Initiator.
Organic Resin Matrix
For a composite to have a good mechanical and physical properties, a strong bond must exist b/w
Organic resin Inorganic filler matrix
Silane coupling agent strength of composite
solubility water absorption
Silane Coupling Agent
wear resistancewear resistance
Divided into 3 types based primarily on
Size AmountComposition
Inorganic Filler
Types of Composite
Types of Composites (cont’n)
Early composite contained
Large Large Micro fine Finespherical irregular particles
particles particles [0.04-0.2 m] [0.5-3
m] [20-30m] Blends (hybrid)
Types of Composites (cont’n)
1. Conventional
2. Micro fill Composites
3. Hybrid
Contain 75 to 80 % inorganic filler by weight ( 50 - 65 vol.)
Particle size range from 1 to 10 m, with the average of 3 m.
Uses:
Class IV and II
Conventional Composites
Disadvantages: Because of the :
large size and extreme hardness of inorganic
filler. It exhibits a rough surface texture
then
surface discoloration higher initial wear
But
they have good physical and mechanical properties.
Designed to replace the rough surface characteristic of conventional composites with :
smooth lustrous surface
Colloidal silica particles 0.02 - 0.4m instead of large filler particles.Results in smooth, polished surface respective to plaque or staining.
Micro fill Composites:
Microfill Composites: (cont’n)
They have 35 to 60% inorganic filler by wt., so it cannot be heavily filled, because of greater surface area per unit volume of this microfine particles (20 - 50 vol.).
Result in: inferior physical and mechanical properties
Higher wear resistant clinically
Uses: ( Anterior rest class III , V )
( low modulus of elasticity )
Developed to combine the good physical and mechanical characteristics of conventional composites with the smooth surface of micro fill composites.
These materials have 70 to 80 % by wt., inorganic filler content (50 – 65 vol.).
Hybrid Composites:
Hybrid Composites: (cont’n)
The filler is a mixture
Conventional Micro fill particles
that have a smaller average particle size than conventional composites [0.5 - 3 m] and bigger than micro fill .
Hybrid Composites: (cont’ n)
Due to the presence of sub-micron sized particles inter spread among the larger particles allows a smooth surface texture to be attained in the finished restoration.
They have good physical and mechanical characteristics. Uses: ( Anterior, posterior, IV )
The physical properties of the composite
resins are improved over those of certain other
esthetic materials.
1) Solubility is not observed.2) Water sorption is lower 3) Fluid exchange within the polymer
decreased, this will promote
Chemically Color Stability
Advantages of Composites:
Advantages: (cont’n)
Mechanical properties of the filled resin also enhanced.
1) It has greater capacity to resist masticatory stress.
2) Surface hardness is higher (resistance to indentation)
3)3) Stiffness is improved Stiffness is improved
(resistance to distortion)(resistance to distortion)
4)4) Dimensional stability is Dimensional stability is improved.improved.
5)5)Initial shrinkage on polymerizationInitial shrinkage on polymerization
is reduced to is reduced to 1/41/4 (less leakage)(less leakage)
Advantages: (cont’n)
6) Thermal coefficient of expansions is decreased by 60% (3x tooth structure)clinically better adaptation to cavity walls and margins. dimensional change during thermal cycling minimized
resulting to
less marginal leakage
Advantages: (cont’n)
7) Thermal conductivity is quite low
resin has capability to insulate from thermal change.
Advantages of Composites
Over Amalgam
1- Esthetic2 - Conserve tooth structure
3 - Strengthening remaining tooth structure4 -No
corrosion5 –No galvanic reaction
Disadvantages
1- Less wear resistance in stress area.
2- Technique sensitivity
3- Higher coefficient of thermal expansion
4- Low modulus of elasticity
Over Amalgam
1) Anterior restoration ( III , IV, V, VI )
2) Posterior restoration ( I , II ) 3) Diastema closure
4) Preventive Resin Restoration5) Veneering
6) FX. Of Anterior teeth
Indications:Indications:
7) Inlay and Onlay7) Inlay and Onlay
1 - ISOLATION
2 - OCCLOUSION
3 – ROOT CARIES
Contraindications
Cavity preparation
Restorative material manipulation
Moisture control
The successful placement of a composite restoration requires meticulous attention to detail regarding
THY
O
NK
U
A
1) Anterior restoration ( III , IV, V, VI )
Indications:Indications: