Composite materials are made of a resin matrix and filler particles. They have superior properties to their individual components. There are several types of composites classified by filler particle size: macrofilled (8-12 μm), small particle (1-5 μm), microfilled (0.04-0.4 μm), and hybrid (1 μm). Macrofilled composites have the largest particles and produce the roughest surfaces, while microfilled composites have the smallest particles and smoothest surfaces. Hybrid composites have a mixture of particle sizes. The different types have various indications for use depending on their mechanical properties and ability to be polished.

2. Composite
o In materials and science, a solid formed from 2 or more
distinct phases that have been combined to produce
properties superior to or immediate to those of the
individual constituents; also a term used in dentistry to
describe a dental composite
• Consists of at least two distinct phases normally formed
by blending together components having different
structures and properties.
2

3. Applications
• Restoration for anterior and posterior
teeth
• Pits and fissure sealants
• Bonding of ceramic veneers
• Cementation of fixed prosthesis

4. components
Matrix
Filler
Coupling Agent
Initiators and accelerators
pigments

5. Resin Matrix
• Bis-GMA (bisphenol-A glyceril methacrylate)
• UDMA (urethane dimethacylate)
• TEGDMA (triethylene glycol dimethacrylate)
If the composite is made up of
just the resin matrix, it is called
Unfilled Resin

6. Matrix
• Phase that polymerizes to form a solid
mass and that bonds to the tooth
structure.
• Weakest and the least wear resistant phase
• Absorbs water, stain and discolor
• Minimize the filler content
• = stronger composite material

7. Filler Particles
• Silica particles
• Quartz
• Glass ( Ba, Sr, Zr)
If the composite is made up of
the resin matrix AND fillers, it is called
Filled Resin

8. Factors for durability of Co Resin
Filler Size Filler Content
• Determines the • As the filler content
surface smoothness. increases, the resin
• Larger particles = content decreases
rougher surface • Hardness and
• Composites are most abrasion resistance
often classified by increases
the filler size.

9. Filler Particles
• Increase fillers, increase
% Filler Volume
mechanical properties 2
Fracture Toughness
– strength 1.5
– abrasion resistance 1
– esthetics
0.5
– handling
0
0 28 37 48 53 62
Ferracane J Dent Res 1995

10. Coupling Agent
• Chemical bond
– filler particle - resin matrix
• transfers stresses
• Organosilane (bifunctional molecule)
– siloxane end bonds to hydroxyl groups on filler
– methacrylate end polymerizes with resin
CH2 OH
Bis-GMA CH3-C-C-O-CH2-CH2-CH2-Si-OH
Bonds with resin Bonds with filler
O OH
Silane
Phillip’s Science of Dental Materials 2003

11. Coupling Agents
• Chemical bond
– filler particle - resin matrix
• Improves physical and mechanical
properties
• Inhibits leaching by preventing water
from penetrating along the resin-filler
interface

12. Optical Modifiers / Pigments
• Provides the opacity or translucency
needed to make the composites similar to
the natural tooth tissue
• Metal oxide particles
– Titanium dioxide
– Aluminum oxide

13. Color Determination
• Should be as close to that of the natural tooth
as possible.

14. POLYMERIZATION SYSTEMS
• Chemical Cure
• Light cure
• Dual cure

15. Polymerization Systems
a. Chemically Activated Materials
- 2 paste systems
1. tertiary amine
2. BPO initiator
- mix at chairside until 2 colors blend

16. • B. Light activated Materials
- Single paste
- Materials set when exposed to a very bright
light.
- Light sources:
- Halogen light
- Plasma arc light
- Argon laser
- Blue emitting diodes

17. • B. Light activated Materials
• SYRINGE single paste
• Free radical initiating system consist of
• Photointiator molecule and amine activator
• Light exposure ( correct wavelength)
• Photoinitiator : camphorquinone
• Amine Accelarator : DEAEMA ( diethyl-
amino-ethyl-methacrylate)

18. • C. Dual Cure
• Consists of 2 light curable pastes
• BPO and aromatic tertiary amine
• Light curing – promoted by amine/CQ
combination
• Chemical- amine/BPO interaction
• APPLICATION:
• Cementation of bulky ceramic inlays

19. CLASSIFICATION OF RESIN-
BASED COMPOSITES

20. CATEGORY AVE PARTICLE SIZE
(µm)
CONVENTIONAL / 8-12
MACROFILLED
SMALL PARTICLE 1-5
MICROFILLED 0.04-0.4
HYBRID 1

21. Macrofilled Composites
• conventional composites,
• traditional composites
• Properties:
– Filler is quartz
– Filler used: finely ground amorphous
silica and quartz
– Filler loading: 70-80 wt% or 60-70 vol%
• May be used as a restoration in stress
bearing areas such as Class IV and II
sites

22. Macrofilled Composites
• Clinical Considerations:
– Produces a rough surface during
abrasive wear
– Finishing of the restoration also
produces a roughened surface
– Tend to discolor over time
– Poor resistance to occlusal wear

23. Small Particle
• To improve surface smoothness and
retain or improve the properties of
traditional composites.
• High filler loading than traditional
• Filler: amorphous silica ,
incorporate glasses
• Compressive strength > macro and
micro
• Tencile strength : x2 micro and 1.5x
macro
• INDICATIONS:
• high stress and abrasion prone (cl
IV)

24. Microfilled Composites
• Properties:
– Filler used: colloidal silica
– Filler size: 0.04 um colloidal silica(200-300
times smaller than the ave particle size of
traditional composites)
– Filler loading: 80 wt%, 60 vol%
• Polish very smooth
• Appearance like enamel

25. Microfilled Composites
• Clinical considerations:
– Bond between the composite particles and
the matrix is relatively weak, making it not
suitable for use as stress bearing restoration
– Produces the smoothest finish
– Indicated for: Class III and Class V cavities

26. Hybrid Composites
• Properties:
– Filler used: colloidal silica AND glass
containing heavy metals
– Filler size: 0.4- 1um
– Filler loading: 75-80 wt%
• Physical and mechanical properties rane
between those of the
traditional and SPF
composites

27. Hybrid Composites
• Clinical considerations:
– Indicated for Class III and IV cases
– Indicated for Class I and II cases
– Indicated for Class V cases

28. Special Use Composite Materials
• Flowable
• Condensable / Packable

29. Flowable Composites
• Has a reduced filler content to make the
material “flowable”
• Indicated for Class I restorations in the
gingival areas
• Used as a cavity base or liner especially for
Class II preparations wherein access is
difficult to achieve
• Used as a pit and fissure sealant

31. Condensable composite
• Has a filler particle that inhibits the filler
particles by sliding to one another
• Stiffer, thicker feel

32. Classification of Resin-Based Composites and Indications for Use