Ideal esthetic material for conservative restorations has resulted in improvements in materials and...

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: