1. Importance of filler particles in clinical application of
composite ?
Generally:
1-Increase tensile strength- essentially preventing the restoration from cracking
2-Reduce polymerisation shrinkage
3-Reduce co-efficient of thermal expansion
4-Improved elastic modulus- allowing a greater strength to be applied without the
elastic body changing shape
5-Provide radio-opacity
6-Control aesthetics- as mentioned varying types of filler produce different
finishes eg small filler particles give a more polished finished
7-improve workability by increasing viscosity
8-reduction in water sorption , softening ,and staining
9-increase radiopacity and diagnostic sensitivity .
10-increase in abrasion resistance .
11-increasedfracture toughness.
12-Enhance physical and mechanical properties to the level of tooth tissue
Clinical performance and durability .
13-Increase translucency ..
14-Improves handling properties .
References:
http://www.slideshare.net/deepthipramachandran/fillers-incomposite-resins
important factors with regard to filler that determine the
properties and clinical ppliation :
amount of filler added :
as filler content increases ,the fluidity reduces .
high filler continent lower water .
size of particles and distribution :
to increase filler loading it is necessary to add filler in range of
particle sizes .
index of refraction
for esthetic material ,should have translucency similar to that
of tooth .

2. radiopacity: one of therreqirements of using a composite as a
posterior restorative is that it should be radiopaque.
Barium – zinc - boron – zirconium .
hardness
Composite type
Microfill
Clinical application
-Enamel replacement in class
III,IV,V restorations
-minimal correction of tooth
from and localized
discoloration .
Properties
Polishability
–Wear resistance
–Water absorption
–Radiopacity
–Polymerization shrinkage
-Posterior resin based
composite restoration
class V restoration
-Dentin build up in class III,IV
restoration
Microhybrid -Posterior and anterior direct
composite restoration
-veneer
-correction the tooth from
discoloration .
Packable
-Posterior resin based
composite restoration.
Flowable -Pits and fissure restoration.
- Liner in class I,II,IV
restoration (dentin )
Radiopacity
Polishability
Physical properties
–Polymerisation shrinkage
Hybrid
Note :+ positive property : performance acceptable
- Negative property : performance unacceptable