Overall Posterior restorative cements.

1. POSTERIOR RESTORATIONS
Presenter: B.NEHA
2nd year post graduate
Dept of Pedodontics
AME’s Dental College and Hospital.

2. CONTENTS
• Amalgam
 Definitions
 Classification
 Setting reaction
 Modifications
• Glass Ionomer Cements
 Classifications
 Setting reactions
 Modifications of GIC
• Composites
 History
 Classification

3. AMALGAM
• It is an alloy containing mercury.
• Dental Amalgam: An alloy of mercury, silver, copper
and tin, which may also contain palladium, zinc and
other elements to improve handling characteristics
and clinical performance.

4. Classification (Marzouk)
• I. According to number of alloy metals:
1. Binary alloys (Silver-Tin)
2. Ternary alloys (Silver-Tin-Copper)
3. Quaternary alloys (Silver-Tin-Copper-Indium).
• II. According to the shape of the powdered particles.
1. Spherical shape (smooth surfaced spheres).
2. Lathe cut (Irregular ranging from spindles to shavings).
3. Combination of spherical and lathe cut (admixed).

5. • III. According to copper content of powder:
1. Low copper content alloy - Less than 4%
2. High copper content alloy - more than 10%
• IV. According to addition of Nobel metals
Platinum
Gold
Pallidum

6. V. According to compositional changes of succeeding
generations of amalgam:
First generation amalgam was that of G. V Black i.e. 3 parts
silver one part tin (peritectic alloy).
Second generation amalgam alloys - 3 parts silver, 1 part tin,
4% copper to decrease the plasticity and to increase the
hardness and strength. 1 % zinc, acts as a oxygen scavenger
and to decrease the brittleness.
Third generation: First generation + Spherical amalgam –
copper eutectic alloy.

7. Fourth generation: Adding copper upto 29% to original
silver and tin powder to form ternary alloy. So that tin is
bounded to copper.
Fifth generation: Quaternary alloy i.e. Silver, tin, copper and
indium.
Sixth generation (consisting eutectic alloy).
• VI According to Presence of zinc.
Zinc containing (more than 0.01%).
Non zinc containing (less than 0.01%).

8. Amalgams setting reaction
γ : Ag3Sn (mechanically the strongest)
γ1 : Ag2Hg3 (major matrix phase in set
amalgam)
γ2 : Sn8Hg (weakest phase, corrodes easily)
β : Ag5Sn
ε : Cu6Sn5
η : Cu3Sn

9. Low Copper Amalgam
• During trituration, mercury diffuses into the silver-tin
particles.
• Then, silver and tin dissolve, to a very limited extent, into
the mercury.
• Because silver is much less soluble in mercury than tin,
silver precipitates out first as silver-mercury (γ1) followed by
tin in the form of tin-mercury (γ2).
• The set amalgam consists of unreacted gamma particles
surrounded by a matrix of gamma 1 and gamma 2.
• The amalgamation is summarised as follows:
• Ag3Sn, Ag5Sn + Hg → Ag2Hg3 + Sn8Hg + Ag3Sn
i.e. (γ + β) + Hg → γ1 + γ2 + γ

10. High Copper Amalgam
• In high copper alloy, copper is added to improve mechanical
properties, resistance to corrosion and marginal integrity.
• The higher copper is supplied by either the silver-copper
eutectic or the Cu3Sn (ε) phase.
• The fact that tin had a greater affinity for copper than for
mercury meant that the gamma-2 phase was reduced or
eliminated.
• This resulted in the dramatic improvement in physical
properties.

11. I. Admixed alloy:
• Contain 2 parts by weight of conventional
composition lathe cut particles plus one part by
weight of spheres of a silver copper eutectic alloy.
• The silver tin particle is usually formed by the lathe
cut method, whereas the silver copper particle is
usually spherical in shape.

12. • Composition of admixed alloy:
Silver-69 %
Copper-13 %
Tin-17 %
Zinc-1 %

13. II. Single composition alloy (Unicomposition):
• It is so called as it contains particles of same composition.
• Usually spherical single composition alloys are used.
• Ternary alloy in spherical form, silver 60%, tin 25%, copper
15%.
• Quaternary alloy in spheroidal form containing Silver: 59%,
copper 13%, tin: 24%, indium 4%.

14. SETTING REACTIONS FOR HIGH COPPER ALLOYS
I) Admixed alloy initial setting reaction:
Ag3Sn + Ag-Cu + Hg Ag3Sn + Ag2Hg3 + Sn8Hg + Ag-Cu
γ γ γ1 γ2
Final reaction
Sn8Hg + Ag-Cu Cu6Sn5 + Ag2Hg3 + Ag-Cu

15. II) Single or unicomposition alloy setting reaction:

16. Advantages of high copper compared
to low copper alloy
• Better corrosion resistance.
• Less susceptible to creep.
• Greater strength.
• Less tarnish and corrosion.
• Longer longevity

17. PROPERTIES
ADA specification No.1 for amalgam lists following
physical properties as a measure of quality of the
amalgam.
• Creep
• Compressive strength
• Dimensional changes
• Modulus of elasticity

18. Flow and Creep
• Time dependent plastic deformation.
• When a metal is placed under stress, it
will undergo plastic deformation.
• The high copper alloys, as compared
with conventional silver tin alloys,
usually tend to have lower creep values.

19. Compressive strength

20. Tensile Strength
Product After 15minutes After 1 hour
Low copper alloys 4.7 55
High copper alloys
a) Admixed
b) Unicompositional
3.0
8.5
43
56

21. Moisture contamination (Delayed Expansion)
• Certain zinc containing low copper or high copper
amalgam alloys which get contaminated by moisture
during manipulation results in delayed expansion or
secondary expansion.
• Occur 3-5 days after insertion and continues for
months.
• Zinc reacts with water, forming zinc oxide and
hydrogen gases.

22. Complications of Delayed Expansion
• Protrusion of the entire restoration out of the cavity.
• Increased micro leakage space around the restoration.
• Restoration perforations.
• Increased flow and creep.
• Pulpal pressure pain, Such pain may be experienced
10-12 days after the insertion of the restoration.

23. Types of Corrosion
Galvanic corrosion:
• Dental amalgam is in direct contact with an adjacent
metallic restoration such as gold crown.
Crevice Corrosion:
• Local electrochemical cells may arise whenever a portion
of amalgam is covered by plaque on soft tissue.
• The covered area has a lower oxygen and higher hydrogen
ion concentration making it behave anodically and corrode.

24. Stress Corrosion:
• Regions within the dental amalgam that are under
stress display a greater probability for corrosion, thus
resulting in stress corrosion.
• For occlusal dental amalgam greatest combination of
stress and corrosion occurs along the margins.

25. DENTAL MERCURY HYGIENE
Recommendations from the ADA include the following:
• The work place should be well ventilated, with fresh
air exchange and outside exhaust.
• Use only precapsulated alloy, discontinue use of Bulk
mercury & bulk alloy.
• Avoid the need to remove excess mercury before or
during packing by selecting an appropriate alloy:
mercury ratio.
• Use an amalgamator with a completely enclosed arm.

26. • Mercury and unset amalgam should not be touched by
the bare hands.
• Floor coverings should be non absorbent & easy to
clean.
• Spilled mercury should be cleaned up using trap
bottles, tape or freshly mixed amalgam to pick up
droplets.
• Do not use a house hold vacuum cleaner to clean
spilled mercury.
• Skin accidentally contaminated by mercury should be
washed thoroughly with soap and water.

27. • In a tightly closed container
• Under radiographic fixer solution.
• Dispose mercury contaminated items in sealed
bags.
• Do not dispose mercury contaminated items in
medical waste containers or bags or along with the
waste that will be incinerated.

28. A
FEW
MODIFICATIONS
OF
AMALGAM

29. Gallium based alloy
• In 19th century public began to express concerns regarding
the use of mercury in dental amalgam.
• As early as 1956, it was claimed that gallium when mixed
with Ni, Sn and Cu produced a pliable mass.
Properties:
• It can be used as a direct restoration
• No mercury
• Gallium is liquid at room temperatures, therefore can wet
surfaces of many solids

32. Consolidated Silver Alloy System
• A recent amalgam substitute that has been tested at
National Institute of Standards and Technology.
• Silver rich metal powders are cold welded by
consolidation, surface of the powder is treated with
fluoroboric acid with pH 1 to keep the surface of alloy
particles clean.
• This can result in a filling material with strength similar
to that of amalgam.
• This alloy is then compacted into the prepared cavity.

33. Resin Coated Amalgam
• A coating of unfilled resin over the restoration margins and
the adjacent enamel, after etching the enamel has been tried
by Meritz & Fairhurst

34. • Mertz-fairhurst and others evaluated bonded and sealed
composite restorations placed directly over frank cavitated
lesions extending into dentin versus sealed conservative
amalgam restorations and conventional unsealed amalgam
restorations.
• The results indicate that both types of sealed restorations
exhibited superior clinical performance and longevity
compared with unsealed amalgam restorations over a period of
10 years (Mertz-Fairhurst, 1998).

36. Anaerobic adhesives cure when in contact with
metal, and the air is excluded, they are based on
modified acrylate acid diesters, otherwise known
as polyester-acrylic monomers

37. Fluoride releasing amalgam
• Have been shown to have anticaries properties
sufficient to inhibit the development of caries in
cavity walls.
• Concentration of fluoride is sufficient to enhance
remineralization.
• However, this release of fluoride decreases to
minor amounts after 1 week.

38. • Forsten L (1976) -- fluoride released from
amalgams loaded with soluble fluoride salts was
detectable within the first month and thereafter
fluoride was not released in measurable amounts.
• Garcia Godoy et al( 1990) – fluoride release can
continue as long as 2 years (but at a much lower
rate than that for GIC).

39. AMALGAM WARS

40. Amalgam wars
In 1845, American Society of Dental Surgeons condemned the
use of all filling material other than gold as toxic, thereby
igniting "first amalgam war'. The society went further and
requested members to sign a pledge refusing to use amalgam.
In mid 1920's a German dentist, Professor A. Stock started the
so called "second amalgam war". He claimed to have evidence
showing that mercury could be absorbed from dental amalgam,
which leads to serious health problems. He also expressed
concerns over health of dentists, stating that nearly all dentists
had excess mercury in their urine.

41. • "Third Amalgam War” began in 1980 primarily through the
seminars and writings of Dr.Huggins, a practicing dentist in
Colorado.
• He was convinced that mercury released from dental
amalgam was responsible for human diseases affecting the
cardiovascular system and nervous system
• Also stated that patients claimed recoveries from Multiple
sclerosis, Alzheimer’s disease and other diseases as a result
of removing their dental amalgam fillings.

42. An EU-wide ban on the use of mercury in the dental
fillings of children and pregnant women came into effect in
July 2019.
According to the new EU regulation:
“The use of mercury in dental amalgam is the largest use of
mercury in the Union and a significant source of pollution. The
use of dental amalgam should therefore be phased down in
accordance with the [Minamata] Convention and with national
plans […]“
Mercury is used heavily in dentistry, but it is easily replaceable..

43. GLASS IONOMER
CEMENTS……….

44. GLASS IONOMER CEMENTS
• ADA specification number: 96
• “Glass-ionomer is the generic name of a group of materials
that use silicate glass powder and aqueous solution of
polyacrylic acid” - Kenneth J Anusavice.
• “Glass ionomer cement is a basic glass and an acidic polymer
which sets by an acid- base reaction between these
components” JW McLean, LW Nicholson. AD Wilson

45. Extensive use of this cement to replace dentin , has
given it different names:
• 1) Dentin substitute
• 2) Man made dentin
• 3) Artificial dentin
• 4) Alumino Silicate Polyacrylic Acid(ASPA)

46. Scientific development:
• D.C. smith in 1968 used poly acrylic acid in zinc
polycarboxylate cement.
• The invention of glass ionomer cement was done in 1969,
first reported by Wilson and Kent in 1971.
• First practical material: in1972 by Crisp and Wilson.
• First marketable material, in 1973

47. COMPOSITION

48. • Alumina (Al2 O3)
- Increase opacity
• Silica (SiO2)
- Increase Translucency.
• Fluoride: Its has 5
functions
- Decrease fusion temp.
- Anti cariogenecity
- Increase translucency
- Increase working time
- Increase strength
• Calcium fluoride (Ca F2) -
Increase opacity
- Acts as flux.
• Aluminium phosphates - -
Decrease melting temp.
- Increase translucency
• Cryolite (Na3 Al F6) -
Increase translucency
- Acts as flux
Glass ionomer cements in dentistry : a review International journal of
plant, animal and environmental sciences 2011;1(1)

49. • Tartaric acid
- Increases WT
- Increases translucency
- Improves manipulability
- Increases strength 5-15% of optically active isomer
of TA is added.
• Polyphosphates: extends Working Time.
• Metal oxides: accelerates Setting Time.

50. CLASSIFICATIONS
• A) According to A.D. Wilson And J.W.Mclean IN 1988
Type I --- luting cements
Type II --- restorative cements
a.Restorative aesthetic
b.Restorative reinforced
• B) ACCORDING TO SKINNERS
Type I – Luting
Type II- Restorative
Type III- Liner and base

51. • C) ACCORDING TO USES:
Type I – Luting
Type II – Restorative
Type III – Liner/base
Type IV – Pit & fissure sealant
Type V – Luting for orthodontic purpose
Type VI – Core buildup material
Type VII – High fluoride releasing command set
Type VIII – Atraumatic restorative treatment
Type IX − Pediatric Glass Ionomer cements

52. • D) NEWER CLASSIFICATION:

53. SETTING REACTION

54. Properties Of Restorative GIC

55. Thermal Compatibility
• The tooth structure and restorative materials in the mouth will
expand upon heating by hot foods and beverages but will
contract when exposed to cold substances.
• Such expansions and contractions may break the marginal seal
of an inlay or other fillings in the tooth, particularly if the
difference in coefficient of thermal expansion (CTE) is great
between the tooth and the restorative material.

56. • Practically relevant temperature range between 20 °C and 60
°C, materials such as resinous composites and amalgam
expand more than the tooth tissue, whereas porcelain and glass
ionomer cements are well adapted to the tooth tissue.
Dental Glass Ionomer Cements As Permanent Filling Materials – Properties
,Limitations And Future Tends – ulrich lohbauer Materials 2010,3,76-96

57. Anticariogenicity
• Fluoride is the most effective agent in caries prevention.
• The metabolism of the bacteria that cause caries is inhibited and
the resistance of enamel and dentin is increased due to the
remineralization of porous or softened enamel and dentin.
• Sustained, long-term fluoride release especially in marginal
gaps between filling material and tooth help prevent secondary
caries of the dental tissues.
• For conventional GIC, an initial release of up to 10 ppm and a
constant long-term release of 1 to 3 ppm over 100 months was
reported.
Dental Glass Ionomer Cements As Permanent Filling Materials – Properties
,Limitations And Future Tends – ulrich lohbauer Materials 2010,3,76-96

58. SANDWICH TECHNIQUE
PIT AND FISSURE SEALENTS
TUNNEL PREPARARTIONS
CORE BUILD UP
CLASS III RESTORATIONS
FEW APPLICATIONS
OF GIC IN
RESTORATIVE
DENTISTRY

59. SANDWICH TECHNIQUE
• First described By Mc Lean & Wilson In 1977.
The procedure involves :-
• Placing GIC as base of cavity .
• Etching with 37% phosphoric acid for 1 min causes
surface roughness
• Dentin bonding agent is applied.
• Placing composite restoration.

60. Advantages included:
• GIC acts as a dentin substitute.
• The high contraction stresses produced (2.8 – 3.9
Mpa) by the polymerization shrinkage are reduced
as the amount of composite is reduced.
• Microleakage is reduced.
• Minimization of no. of composite increments,
therefore time is saved.

61. PIT AND FISSURE SEALANT
• The size of the fissure should allow sharp explorer tip
to enter the crevice which should be >100 µ wide.
Otherwise, GIC can get lost through erosion due to its
low wear resistance and solubility.

62. CORE BUILD UP
• The metal reinforced glass ionomer cements are used
for this purpose .
• Glass ionomer cements reinforce the teeth &prevent
root fracture when root canals are over widened.

63. TUNNEL PREPARATION
• First described by Hunt and Knight in1984
• Conservative alternative cavity preparation in primary molars.
• Indication:- Small proximal caries with out involvement of
marginal ridges.

64. GIC IN ENDODONTICS
They are used for:
• Root end fillings.
• Root canal sealer.
• Perforation repair.
• Intraorifice barriers.
•Temporary coronal restorations.
Clincal application of glass ionomers in endodontics: a review – zahed
mohammadi at al International dental journal 2012;62:244-250

65. RESIN MODIFIED GIC
METAL MODIFIED GIC
MODIFICATIONS OF
GIC

66. MIRACLE MIX / SILVER CERMET
• Silver cermet was introduced by Simmons in year 1983.
• Sced and Wilson in 1980 incorporated spherical silver
amalgam alloy into Type II GIC powder in a ratio of 7:1.
 Powder :
Glass –17.5% • Silver –82.5% Particle size of silver is 3 – 4µm.
 Liquid :
Aqueous solution of copolymer of acrylic acid and or maleic
acid—37% • Tartaric acid 9%

67. Disadvantages:
• Poor resistance to abrasion
• Resistant to burnishing
• Poor aesthetics

68. Glass Cermet
• Also called as cermet ionomer cements.
• McLean and Gasser in 1985 first developed .
• Fusing the glass powder to silver particles through sintering
that can be made to react with polyacid to form the cement.
• Sintering is done at high pressure more than 300MPa and at a
temperature of 800 degrees Celsius which is ground to fine
powder particle size of 3.5 µ.
• 5% titanium dioxide is added as whitening agent to improve
aesthetics.

69. Indications:
• Core build –up material.
• Root caps of teeth under over dentures
• Preventive restoration.
• Temporary posterior restoration
Contraindications :
• Anterior restorations.
• Areas subjected to high occlusal loading

70. • According to a study conducted By Sinha S.P et al they
found photomicrographs of scanning electron microscope
(500x) of silver amalgam showed more marginal gap than
glass ionomer and cermet ionomer cements.
• In this study cermet glass ionomer showed the least
microleakage and the best sealing ability among other
retrograde filling materials.

71. RECENT ADVANCES IN GIC
• Improved Traditional GIC :
-Highly Viscous/ Packable GIC
-Low Viscosity GIC
• Polyacid Modified GIC /Compomer
• New Fluoride Releasing GIC
A)Fluoride Charged GIC
B) Low Ph ‘Smart’ Materials

72. • Bioactive Glass
• Fibre-reinforced GIC
• Giomer
• Zirconomer
• Hainomer
• Amalgomer
• Chlorhexidine Impregnated GIC

73. BIOACTIVE GLASS
• Bioactive glass can form intimate bioactive bonds
with the bone cells and get fully integrated with the
bone.
• Bio-active glass (BAG) can act as a source of a large
amount of CaO and P2O5 in a Na2O–SiO2 matrix with
a rapid dissolution rate and high ionic concentration.

74. • BAG 45S5 exhibits a high bioactivity index (IB = 12.5)
compared to other bio-active materials such as hydroxyapatite
(IB = 3), and therefore it has the potential to remineralise
enamel white spot lesions with an increased rate of HA
formation.
• According to study conducted by hussam et al they found that
BAG exhibited a potential of remineralisation of white spot
lesions to an extent and further modification has a potential to
promote entire mineral gain of treated lesions.
Enamel white spot lesions can remineralise using bio-active glass
and polyacrylic acid-modified bio-active glass powders hussam
mily et al JCD 2014;14

75. FIBRE REINFORCED GIC
• Incorporation of alumina fibres into the glass powder to
improve upon its flexural strength.
• This technology called the Polymeric Rigid Inorganic Matrix
Material or PRIMM developed by Dr. Lars Ehrnsford.
• It involves incorporation of a continuous network / scaffold of
alumina and SiO2 ceramic fibres.

76. Advantages
• Due to the ceramic fibers there is increased depth of cure as
light conduction and penetration is enhanced.
• Polymerization shrinkage is reduced as resin is confined within
the chambers.
• There is also improved wear resistance
• Increase in flexural strength.

77. ZIRCONOMER
• The White Amalgam Zirconomer, is developed to exhibit
strength that is consistent with amalgam, through a rigorous
manufacturing technique.
• The glass component of this high strength glass ionomer
undergoes finely controlled micronization to achieve optimum
particle size and characteristics. The homogeneous
incorporation of zirconia particles in the glass component
further reinforces the material for lasting durability and high
tolerance to occlusal load.
• The polyalkenoic acid and the glass components have been
specially processed to impart superior mechanical and
handling qualities to this high strength glass ionomer.

79. Zirconomer Benefits
• Reinforced with special zirconia fillers to match the strength and
durability of amalgam.
• Sustained high fluoride release for anti-cariogenic benefits especially
in cases with high caries risk.
• Packable and condensable like amalgam without the hazard of
mercury, the risk of corrosion, expansion and thermal conductivity.
• High flexural modulus and compressive strength ensures longevity in
stress bearing areas.

80. • Chemically bonds to enamel/dentin and has tooth-like co-
efficient of thermal expansion resulting in low interfacial stresses
and long-lasting restorations.
• Ceramic fillers impart remarkable radiopacity for accurate follow
up and diagnosis.
• Adequate working time with snap-set reaction.
• Easy mixing and handling characteristics minimize chair time and
enables ease of bulk placement.
• Excellent resistance to abrasion and erosion.

81. NANO HYBRID GIC
• Due to the similarity to that of mineralized bone and dental
tissues, hydroxypatite and fluoro-hydroxyapatite have been
used in many fields of dentistry such as implant dentistry and
caries prevention.
• Addition of nanofluoroapatite (nFAp) to the powder
component of conventional GIC has a positive impact on its
compressive, tensile and flexural strengths of the set cement.
Nano-apatite containing glass ionomers are expected to have
superior bonding to the tooth surface due to the formation of
the strong ionic linkages between the apatite crystals/particles
in the cement and Calcium ions in the tooth structure.

82. HAINOMERS
• These are newer bioactive materials developed by
incorporating hydroxyapatite within glass ionomer powder.
• These are mainly being used as bone cements in oral
maxillofacial surgery and may have a future role as retrograde
filling material.
• Studies have shown that they have a role in bonding directly to
bone and affect its growth and development.
Manvi Malik, Karan Sharma, Vasudha Kak. Chemistry, Composition and
Biocompatibility of GIC’s with future horizons: An Insight. Journal of Dental
Herald 2015:1:2:7-10.

83. Chlorhexidine Impegrenated GIC
• To increase the anticariogenic action of GIC
• Still under experimental stage.
• Experiments conducted on cariogenic organisms
• GIC releases approximately 10 ppm of fluoride during the
1st 48 hrs following its placement in the prepared cavity.
In order to improve the antibacterial characteristics
Chlorhexidine digluconate can be added to it.
Deepalakshmi M, Poorni S, Miglani R, Rajamani I, Ramachandran S. Evalation of the
antibacterial and physical properties of Glass Ionomer Cements containing chlorhexidine
and cetrimide: An in vitro study. Indian J Dent Res 2010:21:552-60.

84. Casein Phosphopeptide Amorphous Calcium
Phosphate Complex (CPP – ACP):
• Incorporation of 1.56% CPP-ACP into the GIC
significantly increases its tensile strength,
compressive strength and significantly enhances the
release of calcium, phosphate, and fluoride ions at
neutral and acidic pH.
Aishwarya Sharma, Mausmi Singh, Vinisha Pandey. Glass
Ionomer Cement-A Phoenix and its new flight. Int J of Research in
Health and Allied Sciences 2015:1:1:9-12.

85. Amalgomer
• Amalgomer technology (ceramic reinforced glass ionomer
cement ) is introduced into restorative dentistry to match the
strength and durability of dental amalgam.
• It contains a high level of fluoride with good aesthetics and
minimal cavity preparation required.
• It bonds to tooth structure and has excellent biocompatibility
and shows all the advantages of GIC.
• Amalgomer shows the conventional acid-base reaction of GIC.
Neveen M Ayad, Salwa A, Elnogoly, Osama M. Badie. An in-vitro study of the
physico-mechanical properties of a new esthetic restorative versus dental
amalgam. J. Clín Odontol 2008:4:3:137-144.

86. COMPOSITES ADA SP.NO.27
• History
• Definitions
• Indications & Contraindications
• Classification
• Composition
• Recent advances

87. • During the first half of the 20th century, silicates were the
only tooth coloured esthetic material available for cavity
restoration.
• In 1956, Dr. R.L. Bowen developed a polymer based on
dimethacrylate chemistry.
• This polymer was generally known as Bis-GMA or Bowen
resin, was made up from the combination of bisphenol – A
and glycidyl methacrylate.

88. HISTORY
• 1955: M. Buonocore-acid etch technique.
• 1956: Dr. Bowen formulated BIS-GMA resin.
• 1962: Silanecoupling agents introduced. Macro filled
composites developed.
• 1964 : Bis-GMA composites marketed.
• 1968 Development of polymeric coatings on fillers
(Dental Fillings Ltd)
• 1970: First photo-cured composites using UV light.
• 1972: Visible light curing unit introduced.
• 1976: Microfilledcomposites developed
• Early 1980’s –posterior composites introduced

89. • Mid 1980’s-Hybrid composites developed I
generation indirect composites
• Early 1990’s-II generation indirect composites
• 1996-Flowablecomposites developed and ceromer
developed
• 1997-Packable composites developed
• 1998-Ormocers developed
• 1999-Single crystal modified composites developed
• 2000- Nanofills and Nanohybrids

90. Definitions
• DCNA
A 3 dimensional combination of at least two chemically different
materials with a distinct interface separating the components.
• STURDEVANT
In materials and science word composite refers to a solid formed
from two or more distinct phases that have been combined to
produce properties superior to or intermediate to those of
individual constituents.

91. Indications
• Class I, II, III, IV,
V, VI
• Core buildups
• Sealants and
preventive resin
restorations
• Esthetic
enhancement
procedures
• Cements
Veneering metal
crowns/bridge
• Temporary
restorations
• Periodontal
splinting
• Enamel hypoplasia
• Composite inlays
• Repair of old
composite
restoration
• Patients allergic to
metals

92. Contraindications
• Isolation
• Subgingival area/root surface
• High caries index
• Habits (bruxism)
• Operator abilities

93. CLASSIFICATIONS
• SKINNER’S (10th ed)
Traditional composites (Macrofilled) 8-12µm
Small particle filled composite – 1-5µm
Microfilled composite – 0.04 – 0.4 µm
Hybrid composite – 0.6 – 1 µm

94. STURDEVANT

95. • Based on curing method:
 Chemical Cure
 Light Cure
UV light
Visible light
 Dual Cure
• Based on consistency
 Light body- flowable
 Medium body- homogenous microfils, macrofils and midifils
 Heavy body- packable hybrid and midifils.

96. COMPOSITION

97. RESIN MATRIX
• A plastic resin material that forms a continuous phase and
binds the filler particles together.
• Principle monomers
Bis-GMA/Bowen resin (1962)
UDMA (1974)
• Other monomers
TEGDMA
HEMA

98. FILLER
• Improve the mechanical properties
• Decrease polymerization shrinkage
• Decrease thermal expansion and contraction
• Decrease water sorption
• Radio opacity.

99. • QUARTZ: Chemically inert
Very hard and difficult to grind
Difficult to polish
• SILICA: Less harder than quartz
• GLASSES WITH HEAVY METALS: Radio opaque
Less inert
Slowly leach out
Shorter lifetime
• FLOURIDE RELEASING FILLERS: Ability to release flourides
Ytterbium triflouride and Ba-Alflourosilicates

101. COUPLING AGENTS
• These bond the filler particles to the matrix.
• They improve properties of resin by transferring stresses
from plastic resin matrix to stiff filler particles.
• Prevent Leaching.
• Organosilanes are most commonly used coupling agents
• Gamma methacryloxypropyl trimethoxysilane

103. OPTICAL MODIFIERS
• To achieve natural tooth like
appearance
• Titanium dioxide and
Aluminium oxide(0.001 to
0.007%wt)
CLINICAL SIGNIFICANCE: Darker shades and greater
opacities have decreased depth of curing so we should
either increase exposure time or apply thinner layers of
material while curing

104. • Clinical significance: Less amount of opacifiers allow too
much light to pass through the restoration, less light is
reflected back or scattered, thus making the restoration
appear dark.
• Excessive opacifier leads to reflection of more light making
restoration look whiter.

105. ACTIVATOR-INITIATOR SYSTEM
TYPE OF COMPOSITE ACTIVATOR INITIATOR
Chemically cured N,N di methyl p-
toluidine
Benzoylperoxide
Light Cured
1) UV Light Tertiary amine Benzoin Methyl ether
2) Visible Light Dimethyl amino ethyl
methacrylate
Camphoroquinone

107. Factors involved in Photo Curing

108. CURING EQUIPMENT
Light emitting diode (LED)
Plasma arc curing (PAC)
Quartz tungsten halogen (QTH)
Argon laser lamps (ALL)

109. Light emitting diode
• Radiate only in blue part of visible spectrum with a
wave length 440-480nm.
• Advantage:
• Light weight
• No filter is needed
• No heat production

110. Quartz tungsten halogen
• This lamp consists of quartz
bulb with tungsten filament in
halogen environment.
• It irradiates both UV and
white light.
• Thus filter is needed to
remove the heat and UV light.
• Disadvantage: Intensity of
bulb decreases with use

111. Plasma arc curing
• It uses xenon gas to produce high intensity white light
so filter is necessary to remove heat and allow the
blue light to be emitted.

112. Argon laser lamp
• It emits high intensity light at a single wave length
(490nm).
• Advantage:
• Increased depth of cure
• Less unpolymerized resin found in resin matrix so good
physical properties.
• Improved bond strength
• Require less time to polymerize (10sec for 2mm)
• Disadvantage:
• Costly
• Heat generation
• More risk to surrounding tissues
• Visual damage
• Increase shrinkage

113. Depth Of Cure And Exposure Time
• Amount of photons absorbed by initiator depends on
Wavelength, Light intensity and Exposure time
• For maximum curing radiant energy influx should be
16,000 mJ/cm2.
• Curing depth should be kept 2-3mm
Light is also absorbed and scattered as it passes
through tooth structure especially dentin ,causing
incomplete curing so in critical areas like proximal
box the exposure time must be increased to
compensate for reduction in light intensity

114. Variables associated with curing

115. Curing Types
Ramped curing
- Stepwise
- Exponential
- Linear
Delayed curing
Soft start curing

117. Pulse delay cure.
• Single pulse of light applied to restoration then followed by
pause then a second pulse with higher intensity and longer
duration.
• The first low intensity pulse slowing the rate of
polymerization, decreasing the rate of shrinkage and stresses in
the composite.
• While the second high intense pulse allow the composite to
reach the final state of polymerization.

119. Things to be noted…..
• A curing lamp with wavelength matching the absorbance
range of photoinitiator must be selected.
• Intensity decreases with distance so lamp tip must be placed
at minimum distance through out exposure interval.
• Curing angle should be 90 degrees to resin surface to
deliver maximum intensity.
• Light emitted by curing units can cause retinal damage.
• Never look directly into light tip and reflected light for
longer periods
• Wear protective eye glasses and shields that filter light both
for operator and patient.

121. Common problems
• Poor isolation
• White line or halo adjacent to the enamel margins
• Voids
• Weak/ missing proximal contacts
• Inaccurate shade
• Poor retention
• Contouring and finishing problems

122. Poor isolation
• Causes:
1. No rubber dam/ leaking rubber dam.
2. Inadquate cotton isolation
3. Preparation so deep gingivally that operating area
cannot be isolated.
• Potential solutions:
1. Repeating the bonding technique if area is
contaminated
2. Use of proper isolation with rubber dam.

123. White line or halo adjacent to the enamel margins
• Causes:
1. Inadquate etching and bonding of that area.
2. High intensity light curing, resulting in polymerization
stresses.
3. Traumatic finishing.
Solutions:
1. Conservatively removing the defective area and re-
restoring.
2. Use of light intermittent pressure for contouring.
3. Using soft start polymerization techniques.

124. Voids
• Causes:
1. Spaces left between the increments
2. Tacky composite pulling away from the preparation.
Solutions:
1. Use of more careful technique.
2. Repairing marginal voids by preparing the area and
re-restoring.

125. Weak/ missing proximal contacts
• Causes:
1. Inadequetly contoured matrix band/ movement of the
band during insertion of composite.
2. inadequate wedging, preoperatively and during
insertion.
3. Matrix band too thick.
Soutions:
1. Proper contoured matrix band & firm wedge insertion.
2. Using hand instruments to hold the matrix band against
the adjacent tooth while curing the increments.

126. Poor retention
• Causes:
1. Inadequate preparation form
2. Contamination of the operating area.
3. Poor bonding technique.
Solutions:
1. Preparing the tooth with adequate bevels or flares
and secondary retention.
2. keeping the area isolated while bonding.

127. Contouring and finishing problems

128. Polymerization shrinkage

129. • Causes:
- Filler content- Low-viscosity (flowable) composites
present volumetric shrinkages upto 5%, in large part
due to their reduced inorganic content.
-Degree of conversion: Selfcured composites, develop lower
contraction stress values than light-cured materials, in part due to
their slower reaction rate, but also because the self-initiated
reaction generates a smaller number of free-radicals than
photoactivation, often resulting in lower degrees of conversion.
Kanca III, J SuhBl. Pulse activation : reducing resin-based composite contraction
stresses at the enamel cavosurface margins. Amercian Journal of Dentistry
1999; 12 : 107-12.

130. • Solutions:
-Increase the filler content and reduce the size of the particles:
The combination of nanomer-sized particles and the nanocluster
formulations reduces the interstitial spacing of the filler particles.
This reportedly provides increased filler loading ,thus, reduced
polymerization stress.

131. - Recently, preheating resin composites have been
advocated as a method to increase composite flow,
improve marginal adaptation and monomer conversion.
The benefits of preheating composites may have an
impact on daily restorative procedures as well, with the
application of shorter light exposure to provide
conversion values similar to those seen in unheated
conditions
Bausch J et al. The influence of temperature on some physical
properties of dental composites. Journal of Oral Rehabilitation. Vol 8 (4)
: 309-17.

132. EFFECT OF CONFINEMENT AND
CONFIGURATION FACTOR
• C-factor theory is originated from Feilzer et al. 1987
• During polymerization the restorative resin shrinks
and pulls the opposing walls and floor of the cavity
closer together. The magnitude of this phenomenon
depends upon the configuration of the cavity.
Lu H et al. Towards the elucidation of shrinkage stress development and
relaxation in dental compoisites. Dental Materials 2004; 20 : 979-86.

133. Clinical Aspect
• Configuration factor (C-factor): refers to the number of bonded
surfaces to the number of unbonded surfaces in a dental
restoration.
𝐍𝐨. 𝐨𝐟 𝐒𝐮𝐫𝐟𝐚𝐜𝐞𝐬 𝐨𝐟 𝐜𝐚𝐯𝐢𝐭𝐲 (𝐁𝐨𝐧𝐝𝐞𝐝)
𝐍𝐨. 𝐨𝐟 𝐂𝐨𝐦𝐩𝐨𝐬𝐢𝐭𝐞 𝐬𝐮𝐫𝐟𝐚𝐜𝐞𝐬 (𝐔𝐧𝐛𝐨𝐧𝐝𝐞𝐝)

134. • The lowest C-factor values are obtained with class IV cavities
because the material has enough unbonded surfaces to flow,
providing stress relief. A high C-factor creates a risk for
debonding of the restoration. Therefore, it is important to have
a lower configuration cavity

135. • Polymerization shrinkage can be minimized by using:
• “Soft-start" polymerization instead of high-
intensity light curing.
• Incremental layering to reduce the effects of
polymerization shrinkage; and a stressbreaking
liner, such as filled adhesive, flowable composite,
or resin modified glass ionomers.
• The application of non or low shrinking restorative
materials.
• The application of non or low shrinking restorative
materials
HOW TO DEAL WITH C-FACTOR

136. Dual Cure Composites
• One paste contains benzoyl peroxide and other contains
aromatic tertiary amine.
• Chemical curing occurs by mixing the pastes and is accelerated
on command with the light source
• Light curing is promoted by the amine/CQ combination
• And chemical curing is promoted by the amine/BP interaction.
• Dual-cure materials are intended for any situation that does not
allow sufficient light penetration to produce adequate
monomer conversion, for example, cementation of bulky
ceramic inlays.

137. ADVANCES IN COMPOSITES
• FLOWABLE COMPOSITES
• PACKABLE COMPOSITES
• SMART COMPOSITES
• COMPOMER
• GIOMER
• FIBRE- REINFORCED
COMPOSITES
• NANO HYBRID COMPOSITES

138. Flowable Composites
The reduced filler makes them more susceptible to wear,
but improves the clinician’s ability to form a well
adapted cavity base or liner, especially in Class II
posterior preparations and other situations in which
access is difficult.
Called dental caulk, as it can flow into small crevices
along restoration margins

139. • USES:
 Sealing gingival floor of the proximal box of Class II
restorations.
 Class V cavities.
 Small Class III cavities.
 First increment of all deep restorations to prevent voids and
porosities and to get good seal.
 Small Class I cavities frequently referred to as ‘Preventive
Resin Restorations’.
 Blocking out cavity undercuts during inlay, onlay and crown
preparations

140. Packable composite
• Has the ability to be packed like amalgam.
• Better contact with the adjacent teeth.
• Better occlusal form
• Utilizes different filler systems:
1. Fibers
2. Trimodal particle distribution (interlock at the time of
packing)
3. Resin impregnated fillers

141. Smart Composites
• Ariston HC in 1998.
• It releases fluoride, hydroxyl and calcium ions, when the
pH in areas adjacent to the restoration drops down (e.g.
plaque accumulation).
•Fluoride release from this material is claimed by the
manufacturer to be lower than glass ionomers but more than
that of compomers.
The paste consists of Barium, Aluminium and Fluoride silicate
glass filler (1micron) with Ytterbium trifluoride, silicon
dioxide and alkaline calcium silicate glass in dimethacrylate
monomers.

142. • Recent materials are based on alkaline glass fillers.
• The release of alkaline ions helps in:
1. Inhibiting bacterial growth
2. Buffering the acids produced by bacteria
3. Reduce the incidence of recurrent caries

143. Minimal shrink composites
1. Increasing the filler load.
• Using prepolymerized composite fillers.
• Using nano-sized fillers (Tetric Evoceram, Ivoclar-
Vivadent)
2. Using organic matrices with lower polymerization
shrinkage:
• Spiro-orthocarbonate, can produce composites with no
setting contraction.
• Oxy bis-methacrylates (bifunctional monomer) shows also a
reduced rate of the polymerization contraction.
• Oxirane and silorane-based monomers (Feltick LS, 3M-
ESPE)

145. Compomers (Polyacid-modified composites)
• Introduced in 1994.
• To have a kind of modified composite having the main
advantages of glass ionomer cement.
• Drawbacks:
• Using bonding systems still mandatory.
• Lower wear resistant < regular composites.
Compositional modifications
Certain liquid monomer (HEMA) is modified by polyacrylic acid
grafts.
Filler particles similar to the powder of glass ionomer cement
(calcium- fluoro-alumino-silicate- glass)

146. Setting reaction occurs in 2 stages
• Stage 1: A typical composite resin network around filler
particles forms on light activation.
• Stage II : occurs over 2-3 months when the water from the
saliva gets absorbed and initiates a slow acid base reaction
with formation of hydro gels within the resin and low level
fluoride release.

147. • The in vitro study conducted by vishnu et al found that the
highest tensile bond strength for compomers and the least
tensile bond strength for chemically cured glass ionomer
cement.
• They concluded that the tensile bond strength of Compoglass
(compomer) is significantly greater than Fuji IX GP and Fuji II.
Comparative evaluation of tensile bond strength and microleakage of conventional
glass ionomer cement, resin modified glass ionomer cement and compomer: An in
vitro study C. Vishnu Rekha et al Contemporary Clinical Dentistry2012;3(4)

148. GIOMER
• To overcome some drawbacks of compomers.
• The filler particles are a kind of pre-polymerized
glass ionomer agglomerates.
Giomers are fluoride releasing light-cured restoratives. They
show a true hybridization of glass ionomers and composites as
they have the fluoride release and recharge of glass ionomers
and the aesthetics, handling and physical properties of
composite resins.
http://www.shofu.com.sg/GiomerList.aspx

149. BULKFIL FLOWABLE COMPOSITES
• SDR (Smart Dentin Replacement) Posterior Bulk Fill
Flowable Base is a single component, fluoride containing, and
visibly light cured radiopaque resin composite restorative
material.
• It has handling characteristics typical of a flowable composite
but can be placed in 4 mm increments with minimal
polymerization stress. SDR has a self-leveling feature that
allows intimate adaptation to the prepared cavity walls

150. Fiber-reinforced composites

151. • Dental applications of FRC:
1. FRC endodontic post
2. Reinforcing denture bases
3. Implant frameworks
4.Bases of orthodontic appliances
5. Fixed prosthesis
6.Periodontal splints.
Clinical Hint Optionally, apply first a thin layer of flowable
composite to the cavity floor before the application of
everX Posterior. Place the everX Posterior on top of the
flowable composite and pack it in the cavity.

152. BIOACTIVE COMPOSITES
• Stimulates mineral apatite formation and natural
remineralisation process at tooth material interface that
knits together restoration and tooth.
• They have demonstrated a low cytotoxicity, with additional
benefits to protect the dental pulp and promote tertiary
dentin formation.
• COMPOSITION:
Bioactive ionic resin
Rubberized resin
Reactive glass filler

153. • Natural esthetics – Highly polishable
• Tough, resilient, fracture and wear resistant, absorbs shock
• Releases and recharges calcium, phosphate and fluoride
• Chemically bonds – Seals against microleakage
• No sensitivity
• Moisture tolerant – Simplified technique.
• ACTIVA is the first bioactive composite with an ionic resin
matrix, a shock-absorbing resin component and bioactive
fillers that mimic the physical and chemical properties of
natural teeth. It releases and recharges with calcium,
phosphate and fluoride ions.
TO BE NOTED:

154. NANOFILLED COMPOSITES
• Nanofilled composites were recently introduced
and they consist of nanomers (5 nm to 75 nm
particles) and “nanocluster” agglomerates as the
fillers.
• Nanoclusters are agglomerates (0.6 µm to 1.4
µm) of primary zirconia/silica nanoparticles (5
nm to 20 nm in size) and the resulting porous
structure is infiltrated with silane.
• Greater polish and gloss retention compared to
microhybrid composites.

156. ANTIBACTERIAL COMPOSITES
• Composite materials due to surface roughness and residual
monomers released after polymerization favor bacterial
colonization much more than other dental materials like
amalgam, gold alloys, or glass ionomer cements.
• Attempts to provide composites with antibacterial activity have
been conducted in two ways.
Alterations to the resin components.
Alterations to the filler components
Monika Łukomska-Szymańska, Beata Zarzycka, Janina Grzegorczyk, et al., “Antibacterial
Properties of Calcium Fluoride-Based Composite Materials: In Vitro Study,” BioMed
Research International, vol. 2016, Article ID 1048320, 7 pages, 2016

158. ORMOCER
• Acronym –Organically Modified Ceramic technology.
• Organically modified nonmetallic inorganic composite
material.
• Introduced by Fraunhofer Institute for Silicate Research.
• Described as 3-dimensional cross-linked copolymer with
multi-polymerization with no residual unreacted monomer
& is more biocompatible

160. • ADVANTAGES
 Cattani-Lorente et al –shrinkage of ormocer equals that of
Hybrid composite despite lower filler content.
 Has thermal coefficient of expansion similar to tooth.
 Low shrinkage(1.88%),High abrasion resisitance,
Biocompatibility, Excellent Esthetics.

161. SELF HEALING COMPOSITES
• Impact damage to composite structures can
result in drastic reduction in mechanical
properties.
• Bio-inspired approach is adopted to effect self
healing which can be described as mechanical,
thermal or chemically induced damage that is
autonomically repaired by materials already
contained within the structure.
• Resin matrix- GRUBB’s catalyst.
• Dicyclopentadiene (DCPD) in microcapsules
Yongjing Wang, Self-healing composites: A review,
Journal Cogent Engineering,Volume 2, 2015 - Issue 1

163. REFERENCES
• Glass ionomer cements in dentistry : a review International journal
of plant, animal and environmental sciences 2011;1(1)
• Yongjing Wang, Self-healing composites: A review, Journal Cogent
Engineering,Volume 2, 2015.
• Monika Łukomska-Szymańska, Beata Zarzycka, Janina Grzegorczyk,
et al., “Antibacterial Properties of Calcium Fluoride-Based
Composite Materials: In Vitro Study,” BioMed Research
International, vol. 2016, Article ID 1048320, 7 pages, 2016
• Comparative evaluation of tensile bond strength and microleakage
of conventional glass ionomer cement, resin modified glass ionomer
cement and compomer: An in vitro study C. Vishnu Rekha et al
Contemporary Clinical Dentistry2012;3(4)

164. • Aishwarya Sharma, Mausmi Singh, Vinisha Pandey. Glass
Ionomer Cement-A Phoenix and its new flight. Int J of Research
in Health and Allied Sciences 2015:1:1:9-12.
• Manvi Malik, Karan Sharma, Vasudha Kak. Chemistry,
Composition and Biocompatibility of GIC’s with future
horizons: An Insight. Journal of Dental Herald 2015:1:2:7-10.
• Deepalakshmi M, Poorni S, Miglani R, Rajamani I,
Ramachandran S. Evalation of the antibacterial and physical
properties of Glass Ionomer Cements containing chlorhexidine
and cetrimide: An in vitro study. Indian J Dent Res
2010:21:552-60.

165. • Lu H et al. Towards the elucidation of shrinkage stress
development and relaxation in dental compoisites. Dental
Materials 2004; 20 : 979-86.
• Bausch J et al. The influence of temperature on some physical
properties of dental composites. Journal of Oral
Rehabilitation. Vol 8 (4) : 309-17.
• Kanca III, J SuhBl. Pulse activation : reducing resin-based
composite contraction stresses at the enamel cavosurface
margins. Amercian Journal of Dentistry 1999; 12 : 107-12.