1. GOOD AFTERNOON!!!!!

2. FILLERS IN COMPOSITE
RESINS
DEEPTHI P.R.
FINAL YEAR BDS

3.  Introduction
 Materials used
 Types of Fillers
 Methods of Preparation
 Methods of Incorporation
 Functions of Fillers
 Factors Influencing the Functions of
Fillers

4.  Advantages & Drawbacks of different
Materials
 Classification of Composite Resins
based on Fillers
 Recent Advances
 Summary
 References

5. INTRODUCTION
Composite
In materials and science, a solid formed
from two or more distinct phases that
have been combined to produce
properties superior to or intermediate
to those of the individual constituents

6. Dental Composite
Highly cross-linked polymeric materials
reinforced by a dispersion of glass,
crystalline or resin filler particles
and/or short fibers bound to the matrix
by silane coupling agents
 Dr. Ray L. Bowen (1962)

7. Basic Components
Matrix
Filler
Coupling agent

8. FILLERS
‘The inorganic and/or organic resin
particles that are designed to
strengthen a composite, decrease
thermal expansion, minimize
polymerization shrinkage and reduce
the amount of swelling caused by
water sorption’

9. FILLERS
 Dispersed phase of composite resins
 1950’s- Quartz in MMA filling materials

10. MATERIALS USED
 Quartz
 Amorphous Silica
 Glass fillers with metals
 Colloidal Silica
 Ceramics
 Organically modified
Ceramics/ORMOCERS

11. TYPES OF FILLERS
 3 filler categories- 35 years
Conventional
Microfine
Hybrid

12. CONVENTIONAL FILLER
 Irregular glass or ceramic
 4µm - 40µm
 Used in 1960’s- 1970’s
 First generation Composites: 1-50µm
 60-80 wt%
 Currently: 1-5µm
 Ba, Sr, Zn, Yb glasses- fine fillers
-Radiopacity

13. MICROFINE FILLER
 Pyrogenic silica: 0.01µm- 0.1µm
 Colloidal silica
 30-60 wt%
 Rare earth metal compounds-
Radiopacity
 Homogeneous & Heterogeneous

14. HYBRID FILLER
 Conventional glass/ ceramic filler
particles
-Zirconia/ Silica: 0.5µm - 10µm
 Pyrogenic silica: 0.01µm - 0.1µm
 Bariumaluminoborate & Sr glasses-
Radiopacity
 78-85 wt%

15. MEGAFILLER
 Pieces of glass: 0.5mm – 2mm
 Inserts
 Composites at points of heavy
occlusal contact or high wear

16. METHODS OF PREPARATION
 Grinding or milling Quartz/ Glasses:
0.1µm-100µm
 Microfillers:
Pyrolytic or Precipitation process
fumed silica
- SiCl4 in O2 & H2  macromolecule
chains of SiO2

17. METHODS OF PREPARATION
Colloidal particles of Sodium silicate to
water & HCl colloidal silica
Organic fillers:
 Pulverized precured resin:5µm-30µm
Silane treated colloidal silica to the
monomer at slightly elevated
temperature

18. METHODS OF PREPARATION
Composite paste heat cured with
Benzoyl Peroxide
Cured composite : ground into
particles of size larger than traditional
fillers

19. METHODS OF INCORPORATION
CONVENTIONAL FILLER PARTICLES
Surface coating of ‘Coupling agent’
Then blended with resin
MICROFILLER PARTICLES
Organic fillers + silane treated colloidal
silica blended with monomer

20. METHODS OF INCORPORATION
1. Homogeneous :
Microfiller loaded directly to the resin
2. Heterogeneous
Microfiller compressed into clumps:
Sintering, precipitation, silanization or
condensation
Fumed silica added to a heated resin
at ~70 wt%

21. METHODS OF INCORPORATION
Increase Filler loading
 Sinter colloidal silica particles: Several
tenths of a µm
Reduces compromise in the rheology
 Grinding prepolymerized composite
highly loaded with colloidal silica
particles
Particles then incorporated

22. FUNCTIONS OF FILLERS
 Strengthen the composite
 Reduce the amount of matrix material
 Reinforcement of the matrix resin:
increased hardness, strength &
decreased wear
 Reduction in polymerization shrinkage

23. FUNCTIONS OF FILLERS
 Improved workability by increasing
viscosity
 Reduction in water sorption, softening
& staining
 Increased radiopacity & diagnostic
sensitivity

24. FUNCTIONS OF FILLERS
 Reduction in thermal expansion &
contraction
 Increased compressive strength,
tensile strength, modulus of elasticity
 Increase in abrasion resistance
 Increased fracture toughness

25. FUNCTIONS OF FILLERS
 Enhances physical & mechanical
properties to the level of tooth tissue
 clinical performance & durability
 Increases translucency
 Improves handling properties

26. FACTORS INFLUENCING THE
FUNCTIONS OF FILLERS
FILLER SIZE
 Large : ‘plucking’ – rough surface
- increased wear
- reduced flexural strength
 Size can’t be reduced beyond limits-
technical problems

27. FACTORS INFLUENCING THE
FUNCTIONS OF FILLERS
INCORPORATION OF RADIOPAQUE
COMPOUNDS
 Sr/Ba glass & other heavy metal
compounds
 Rare earth metal compounds

28. FACTORS INFLUENCING THE
FUNCTIONS OF FILLERS
FILLER CONTENT
As it increases:
 Reduced polymerization shrinkage
 Coefficient of thermal expansion-
more like tooth structure
 Increased hardness & abrasion
resistance

29. FACTORS INFLUENCING THE
FUNCTIONS OF FILLERS
 Increased color stability
 Increased depth of cure
 Increased stiffness
 Reduced resistance to toothbrush
abrasion & wear by hydroxyapatite
SILANE COATING
 Increased resistance to hydrolytic
degradation

31. FACTORS INFLUENCING THE
FUNCTIONS OF FILLERS
FILLER SHAPE
Spherical shape:
 Incorporates more inorganic fillers
 Improves fracture strength
REFRACTIVE INDEX
 Matches that of resin ~ 1.50
 Translucency similar to the tooth
structure

32. ADVANTAGES & DRAWBACKS
FILLER ADVANTAGES DRAWBACKS
Quartz .Clinically inert (insoluble)
.Strong & hard
.Difficult to grind into very fine
particles
.Adequate Refractive index
.Highly esthetic
.Difficult to polish
.Potentially abrasive to
opposing teeth or
restorations
Amorphous
silica
.Composition & Refractive index
same as quartz
.Less hard
.Not crystalline
Glass fillers
with heavy
metals
.Adequate Refractive index
.Provide radiopacity
.Not as inert as quartz &
amorphous silica
.Leaches &weakens in
acidic juices & oral fluids
.More susceptible to wear
.Shorter functional
lifetime
.Attacked by APF
gels/solutions

33. CLASSIFICATION OF
COMPOSITES BASED ON
FILLERS
I. Based on the filler particle Size &
Size Distribution
 Traditional (large particle) 1-50 µm
 Hybrid (large particle) :
(1) 1-20 µm glass
(2) 0.04 µm silica
 Hybrid (midifiller) :
(1) 0.1- 10 µm glass
(2) 0.04 µm silica

34.  Hybrid (Minifiller/ Small Particle Filled):
(1) 0.1-2 µm glass
(2) 0.04 µm silica
 Packable Hybrid:
Midifiller/ Minifiller Hybrid but with lower
filler fraction
 Flowable Hybrid:
Midifiller Hybrid, but with finer particle
size distribution

35.  Homogeneous Microfill: 0.04 µm silica
 Heterogeneous Microfill:
(1) 0.04 µm silica
(2) Prepolymerized resin
particles containing 0.04 µm silica

36. II. According to Skinner
 Traditional/Conventional: 8-12 µm
 Small Particle Filled Composites: 1-5µm
III. Philips & Lutz Classification
 Macrofiller Composites: 0.1- 100 µm
 Microfiller Particles: 0.04 µm
 Hybrid Composites: different sizes

37. IV. Based on Mean Particle Size of
the filler
 Traditional Composite resins
 Hybrid Composite resins
 Homogeneous Microfilled Composites
 Heterogeneous Microfilled
Composites

38. V. According to Bayne & Heyman
 Megafill : 1-2mm
 Macrofill: 10-100µm
 Midifill: 1-10µm
 Minifill: 0.1-1µm
 Microfill: 0.01-0.1µm
 Nanofill: 0.005-0.01µm

39. VI. Williams Classification
 Densified Composite Midway filled
 Ultrafine Midway filled
 Fine Midway filled
 Ultrafine cement filled
 Fine cement filled

40.  Homogeneous Microfine Composite
 Heterogeneous Microfine Composite
 With splintered prepolymerized filler
 With agglomerated prepolymerized
filler
 With spherical prepolymerized filler

41. RECENT ADVANCES
NANOFILLED COMPOSITES
 Nanomers (5nm-75nm) &
‘nanocluster’ agglomerates
(0.6 µm -1.4 µm)
 Primary Zirconia/ Silica
nanoparticles(5nm-20nm) fused;
infiltrated with silane
 ‘Nanohybrid’ Composites:
Incoporation of nanoparticles into
composite formulations

43. RECENT ADVANCES
PROPERTIES :Nanofilled vs Others
 Physical & mechanical- similar to
microhybrid
 Water sorption similar to midifill &
microfill
Significantly better polish & gloss
retention
Lower solubility
Reduced scattering of curing light

44. RECENT ADVANCES
 Nanohybrid variety :
- properties similar to / better than
microhybrid
- inferior compared to nanofilled
Nanodiamond filler:
Improve wear resistance & flexural
strength in proportions of
0.005%-0.008%

45. RECENT ADVANCES
FLAKE SHAPED GLASS FILLER(FSG)
 Thin glass platelet with a flat, smooth
surface
 Good transparency
 Increased hardness
 Compressive strength ~ commercial
composite
 High flowability

46. RECENT ADVANCES
POLYMETHYLMETHACRYLATE
(PMMA) FILLER PARTICLES
 2wt% additional PMMA fillers
 Inhibit crack propagation
 Enhance compressive strength
 No significant change in water
sorption/ water contact angle of the
surface

47. RECENT ADVANCES
SILANE COATED GLASS FILLERS
 Fluoroboroaluminosilicate glass
coated with
3- methacryloxypropyltrimethoxysilane
Or 3-aminopropyltrimethoxysilane
 Greater amount of fluoride release
 Higher pH value

48. RECENT ADVANCES
LEUCITE CONTAINING CERAMIC
FILLER
 IPS Empress ingots ball milled;
passed through an 800 mesh sieve
 Significant wear resistance

49. SUMMARY
 Fillers
– reduce curing shrinkage
-- improves physical properties
 Composite characteristics change:
- Material
- Size & size distribution
- Load
- Shape
- Surface modifiers
- Optical index

50. REFERENCES
 Philip’s Science of Dental Materials-
Anusavice,11th Edition
 Applied Dental Materials-John F
McCabe & Angus,W.G.Walls,8th
Edition
 Introduction to Dental Materials-
Richard van Noort,2nd Edition
 Tooth colored Restoratives, Principles
& Techniques- Albers,9th Edition

51. REFERENCES
 The Clinical Handing of Dental
Materials-Smith,Wright,Brown,2nd
Edition
 Clinical aspects of Dental Materials-
Gladwin&Bagby
 Dental Materials-Carol
Dixon,Hatrick,Eakle
 Dental Materials- John M
Prowers,John C.Wataha

52. REFERENCES
 Sturdevant’s Art & Science of
Operative Dentistry- 4th Edition
 Textbook of Operative Dentistry- Nisha
Garg & Amit Garg
 Textbook of Dental Materials-Sharmila
Hussain

53. REFERENCES
 Constantinos Masouras et al
Dental Materials Vol 24 No.7 July 2008:
932-939
 Lim YK et al
Dental Materials Vol 24 No.1 January
2008
 Tahimoto Y et al
Acta Biomaterials 2006 Nov;2(6): 633-
639

54. REFERENCES
 Kondo Y et al
Dental Materials J,2010 October
14;29(5): 596-601
 Itota T et al
Dental Materials J,2010 August
7;29(4):362-368
 Arikawa H et al
Dental Materials J,2007 Jan 26(1):38-
44

55. REFERENCES
 H St.Germain et al
Journal of Dental Research Feb 1985
Vol64 No.2:155-160
 Dr Moraes RR et al
Operative Dentistry 2009 Sep-
Oct;34(5):551-557
 Berger SB et al
Brazil Dental Journal 2009;20(4):314-
318

56. REFERENCES
 J. Mat.Sci.Mater Med.2007
Jun;18(6):1157-1162
Clinical Materials Review
Inside Dentistry July/August 2007 Vol
3,Issue 7
 Motohiro UO et al
Journal of the Ceramic Society of
Japan,Vol 118 (2010), No.1378
June :425-427

57. REFERENCES
 Zhong –Yu- Xiu et al
Effects of Nanodiamond Filler on
Compressive strength &
Microhardness of Composite Resins
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