The document discusses fillers used in composite resins. It describes the various types of fillers including conventional, microfine, and hybrid fillers. The key materials used are quartz, amorphous silica, glass, and ceramics. Methods of preparing and incorporating fillers into the resin matrix are also outlined. The functions of fillers include strengthening the composite, reducing shrinkage, and improving mechanical properties. Recent advances include nanofillers and flake shaped glass fillers.

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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