1. SEMINAR ON
PRESENTED BY :
GUIDE: DR.VISHNUVARDAN(prof) K.SHAILASRI
& DR.RANGAREDDY(prof) BDS 4th YEAR

2.  Glass Ionomer is the Generic name of a group
of materials that use silicate glass powder and
an aqueous solution of polyacrylic acid.
Alumino silicate powder

3.  They are a hybrid of dental silicate and zinc
poly carboxylate and are called as
polyalkenoate cements, ASPA.
 Glass ionomer is a combination of
„Glass‟powder and „ionomer‟-ic acid
 GIC can be defined as a water- based material
that hardens following an acid-base reaction
between the basic fluoro aluminosilicate glass
powder and an acidic solution of polyacrylic
acid.

4. CLASSIFICATION
 Type I – Luting
 Type II- Restorative
 Type III- Liner and base

5. CLASSIFICATION
1. Glass ionomer cements
a. (i) Glass polyalkeonates
(ii) Glass polyphonates
b. Resin modified GIC
c. Polyacid modified composite resin
2. a. Auto-cure
b. Dual cure
c. Tri cure

6. CLASSIFICATION
3. a. Type I – Luting
b. Type II - Restorative
Type II. 1. Restorative aesthetic
Type II. 2. Restorative reinforced
c. Type III- Lining or Base

7. CLASSIFICATION
1.Traditional or conventional
2. Metal modified GIC
a. Cermets
b. Miracle mix
3. Light cured GIC
4. Hybrid (Resin modified GIC)
5. Polyacid modified resin composite or
Compomer

8. CLASSIFICATION
:
1. Type I - Luting
2. Type II - Restorative
3. Type III - Fast setting lining
4. Type IV - Fissure sealants
5. Type V - Orthodontic cements
6. Type VI - Core build up material
7. Type VII - High fluoride releasing
command set GIC
8. Type VIII - GIC for Atraumatic
Restorative
Treatment (ART)
9. Type IX - Geriatric and Paediatric GIC

9. COMPOSITION
:
The composition of the glass is an acid soluble
Formed by fusing silica[Sio2], alumina [Al2O3],
calcium fluoride / fluorite(CaF2), metal oxides and
metal phosphates at 11000C to 15000C temperature.
The glass is crushed, milled and then ground to a
fine powder {20u – 50u)

10. COMPOSITION OF CALCIUM FLUROALUMINOSILICATE
GLASS POWDER
COMPONENT WEIGHT%
SiO2 [quartz] 29
Al2O3 [alumina] 16.6
CaF2[fluorite] 34.2
Na3AlF6[cryolite] 5
AlF3 5.3
AlPO4 9.9

11. COMPOSITION
•The liquid was an aqueous solution of
in a concentration of about 50%.
•The liquid was quite viscous and tended to gel over
time.
•Hence, acrylic acid was copolymerised with other
acids such as iticonic ,maleic,and tricarboxylic acid.

12. COMPOSITION
The use of copolymer :
- Decrease the viscosity of the liquid
- Reduces the tendency for gelation and thus
improving storage
- Increases the reactivity of the liquid

13. COMPOSITION
•It is one of the most important constituents of glass
ionomer cement.
•It is the reaction medium
•30%

14. COMPOSITION
The polyacrylic acid can be vacuum dried
and incorporated with the glass powder.
The liquid then used can be either water or a
dilute aqueous solution of tartaric acid.

15. SETTING REACTION
 The setting reaction of glass Ionomer
cements involves three overlapping stages.
Stage1: Dissolution
Stage2: Precipitation of salt, gelation and
hardening
Stage3: Hydration of salts.

16. SETTING REACTION
 At the beginning of reaction the surface of
glass particles is attacked by the polyacid.
 The hydrogen ions that are released from the
acid diffuse to the glass, and make up for the
loss of the calcium aluminium and fluoride
ions.

17. SETTING REACTION
 During this stage calcium and aluminum ions
bind to polyanions via the carboxylate groups.
The initial set is achieved by cross-linking of
the more readily available calcium ions.
 This is the gelation phase and this reaction is
relatively rapid, usually forming a clinically
“hard” surface within 4-10 minutes from the
start of mixing.

18. SETTING REACTION
 Maturation occurs over the next 24
hours as the less mobile aluminium
ions become bound within the
cement matrix, leading to more rigid
cross linkng between the polyacid
chains.
 Fluoride and phosphate ions form
insoluble salts and complexes.
 Sodium ions contribute to the
formation of an orthosilicic acid on
the surface of the particles

19. SETTING REACTION
 Associated with the maturation phase is a
progressive hydration of the matrix salts,
leading to sharp improvement in the
physical properties

20. SETTING REACTION
The glass ionomer cements are water-based cements.
It‟s functions include:
 It is reaction medium.
It serves to hydrate the siliceous hydrogel and the
metal salts formed.
 It is essential part of the cement structure.
If water is lost from the cement by desiccation while it
is setting, the cement-forming reactions will stop.

21. Water present in the set cement can be arbitarily
classified into:
 “ ” which is readily removed by
desiccation.
This water is loosely bound to the calcium ions
 “ ” which cannot be removed.
Tightly bound water is associated with the
hydration shell of the aluminium cation-
polyacrylate bond and some silica gel water.

22. ADHESION OF GIC
Glass ionomer cements have the important property
of adhering to untreated enamel and dentin. It
reacts with the smear layer on cut dentin and also
bonds to other reactive polar substrates such as the
base metals.
Adhesion – 225MN/m2 after 7 days

23. ADHESION OF GIC
Polyalkenoic acid attacks the dentine and enamel and
displaces phosphate and calcium (or strontium) ions.
These migrate into the cement and develop an ion enriched
layer firmly attached to the tooth structure.
Dentinal tubules will remain sealed and microleakage can
only occur into the cement.

24. Mechanical Properties
 Compressive Strength :150-200 Mpa. compressive
strength is increased by increasing alumina
content but this is achieved at the expense of
translucency. The finer the particles the more will
be the compressive strength
 Tensile Strength :Glass ionomers has a higher
tensile strength when compared with silicates
tensile strength 6.5 Mpa –17.4 Mpa.
 Flexure strength :Glass Ionomer cements are
relatively brittle having a flexure strength of only
15-20 Mpa and can not be considered suitable
purpose filling material for permanent teeth.

25. Mechanical Properties
 Hardness :It is less than that of silicates the
value is 48 KHN
 Fracture Toughness :Glass Ionomer cements
are much inferior to composites in this aspect.

26. PHYSICAL PROPERTIES
BIOCOMPATIBILITY:
 The glass ionomer cements are
therapeutic materials. Their adhesion to
tooth material ensures that they provide an
excellent and enduring marginal seal, thus
eliminating secondary caries while
sustained release of fluoride confers
resistance to caries on adjacent tooth
material (i.e. there is a reduction in
„contact‟ caries).
 These cements are not only biocompatible
they are bio-active, because when they are
used as bone cements they promote bone-
healing

27.  Fluoride ions released from the restorative
materials become incorporated in
hydroxyapatite crystals of adjacent tooth
structure to from structure such as
fluorapatite that is more resistant to acid
mediated decalcification.
 The fluoride originates from that used in
preparing the alumino silicate glass, which
can contain upto 23% fluoride

28. DURATION OF FLUORIDE RELEASE
 Large amounts of fluorides are released
during the first few days after placement
after which it gradually declines during the
first week and stabilizes after 2-3 months and
continues for a long time that is 8 years after
placement and certainly longer.

29.  The glass ionomer cement is an aesthetic
filling material because it has a degree of
translucency which arises because it‟s filler is a
glass.
 The colour of glass ionomer remains
unaffected by oral fluids as compared to
composites which tend to stain.

30. A correctly manipulated and protected glass
ionomer material shows a volumetric setting
contraction of approximately 3% which develops
slowly through the setting process.

31. Thermal Properties:
 The thermal diffusivity value of glass Ionomer
cement ions is close to that for dentin. Hence
the material has an adequate thermal
insulating effect on the pulp and helps to
protect it from thermal trauma

32. 1. RESTORATIVE MATERIALS:
• Restoring of erosion/ abrasion lesions without
cavity
preparation.
• Sealing and filling of occlusal pits and fissures
• Restoration of deciduous teeth.
• Restoration of class III lesions, preferably using a
lingual approach with labial plate intact.

33. • Repair of defective margins in restorations
• –
proximal lesions –buccal
and occlusal approach (tunnel
preparation)
• Core build-up
• Provisional restorations where future veneer
crowns are
contemplated
• Sealing of root surfaces for over dentures.

34. 2. FAST SETTING LINING CEMENT AND BASES:
• Lining of all types of cavities where a biologic
seal and cariostatic action are required
• Replacement of carious dentin or the
attachment of composite resins using the acid etch
technique
• Sealing and filling of occlusal fissures showing
early signs of caries.
3. LUTING CEMENT:

35. CONTRAINDICATIONS:
 Class IV carious lesions of fractured incisors.
 Lesions involving large areas of labial
enamel where esthetics is of major importance
 Class II carious lesions where conventional
cavities are prepared; replacement of existing
amalgam restorations.
 Lost cusp areas.

36. CLINICAL STEPS FOR GLASS
IONOMER RESTORATION
 ISOLATION
 TOOTH PREPARATION A) Cavity
preparation
B) Prophylaxis
C) Surface conditioning
 PROPER MANIPULATION OF THE
CEMENT
 CAREFUL FINISHING AND POLISHING
 PROTECTION OF RESTORATION

37. ISOLATION:
Glass isonomer cements are sensitive to
moisure contamination during placement,
so we need to isolate the tooth surface using
rubberdam,cottonrolls,retraction cords
and saliva ejectors.
TOOTH PREPARATION :
 It consists of A) Cavity preparation- this
is required while restoring class III or class
V carious lesions. For abration and erosion
defects there is no need of cavity

38.  B) Prophylaxis- It is done
usingpumiceslurry carried in a bristle
brush. This will remove any plaque or
salivary pellicle from tooth surface
 C) Surface conditioning- It is an important
step in promoting good adhesion using 10%
polyacrilic acid for 10 to 15 seconds. Other
agents are 10% citric acid, 3% hydrogen
peroxide, 10% EDTA, 25% tannic acid.
Advantages are a) It lowers the surface
energy of the tooth thus increasing
wettability by glass ionomer cement b) It

39. MANIPULATION OF GIC
a. Dispense both powder and liquid
carefully. Turn the liquid bottle to the
horizontal briefly to allow liquid to flow
into the tip before turning it to the
vertical and squeezing out a single
drop.
b. Divide the powder into two equal parts
and prepare to mix.
c. Incorporate the first half of the powder
within 10 seconds, rolling the powder
into the liquid without spreading the
mix over the slab. Do not spatulate too
much.
d. Complete the mixing within 25-30
seconds. For preference, place into a
disposable syringe for transfer to the
cavity.

40. 1. the appropriate of the cement.
2. the tooth with rubber dam where there
is any risk of gingival Seepage or bleeding.
---Erosion/abrasion lesion:-
clean only with pumice slurry
---Carious lesion: conventional
instrumentation to remove caries and provide
some mechanical retention.

41. 4. Where there is less than 0.5mm of
remaining dentin. Line the cavity with a
setting
5. Apply a to the cavity to
remove the smear layer and improve
adhesion.
for 30seconds

42. Polyacrylic acid:
 10% polyacrylic acid for 10 seconds.
 It removes surface debris and smoothes out
irregularities.
 It tends to open up dentinal tubules.
 It is the conditioner of choice as it is a part of
the cement forming system.

43. Citric acid:
50% citric acid for 5 seconds was the earliest
conditioner used
:
25% for 30 seconds.

44. 7. Dispense the cement on a cooled glass
slab and mix quickly (30 seconds for hand
mixing and 10 seconds for
machine mixing).
Alternatively a paper pad can be used. The
mix should have a glossy appearance.
8. The surface should be
as this tends to reduce the
wettability.
9. Insert the cement using a spatula or a
syringe

45. 10. Place a preshaped wherever
possible.
Allow to set.
11. Remove the matrix and

46. 13. Trim any excess, external to the cavity with
scalpel blade.
14. Reapply varnish or bonding agent.
15. The final should be till
the next appointment or at least
16. or bonding agent after
polishing.

47. Glass ionomers are available commercially
in two forms:
- supplied separately, or
hand mixing.
- or mechanical mixing.

48. HAND MIXING:
Certain points to be noted while mixing and
dispensing GIC are:
• Low exotherm while mixing GIC enables all
the powder to be incorporated into the
liquid
 The recommended P:L ratio should be
followed.(3:1)

49.  Mixing on a chilled slab can significantly
prolong working and setting time.
 Plastic or agate spatula are usually used
for mixing
 A smooth glossy plastic paste should be
produced by spreading the mix across the
slab and then re-gathering it to reduce

50.  A dry mix will not adhere to the tooth due to
insufficient wetting. A glossy mix indicates the
presence of free surface polyacid for ion
displacement at the enamel dentin interface.
 Setting time – Type I – 4 to 5 minutes
Type II- 7 minutes

52. USES
 BAND AND BRACKET CEMENTATION.
 CORE BUILD-UP CEMENTS – TYPE VI GIC.
 HIGH FLUORIDE RELEASING COMMAND
SET GIC-TYPE VII GIC.
 GIC FOR ATRAUMATIC RESTORATIVE
TREATMENT TYPE VIII GIC.

53.  GERIATRIC AND PAEDIATRIC GLASS
IONOMER CEMENTS- TYPE IX GIC

 ROOT CANAL SEALING
 RETROGRADE ROOT CANAL FILLING
 PERFORATION REPAIR
 TREATMENT OF VERTICAL FRACTURES
 CORONAL SEALING AFTER ROOT CANAL
TREATMENT

54. Uses of GIC
EROSION / ABRASION LESIONS
CLASS V CARIOUS LESIONS
CLASS III CARIES
MNIMAL CAVITY PREPARATIONS

55. Pits and fissures Primary Teeth restorations
Bracket Bonding

56. Luting of crowns
Core Build-up

57. GLASS IONOMER AS LINER AND BASE
Glass-ionomer cement as a lining. A lining is
used to protect the pulp from temperature
change so the lining needs to be only 0.5mm
thick overall.
Glass-ionomer cement as a base.

58. LAMINATION OR SANDWITCH TECHNIQUE
 This technique involves a combination of
glass Ionomer cement and composite or
amalgam. The rationale behind the
technique is to make the most of the
physical and aesthetic properties of each
material.
 Ionic adhesion of glass Ionomer cement to
the dentin with release of fluoride and thus
making the area resistant to recurrent
caries.
 Less composite resin to be placed, thus
minimizing the ultimate shrinkage of the
composite resin, which will occur during
light activation.
 Minimize the number of increments of
composite resin to be placed and light
activated, thus saving time.

59. Main Steps in this Technique:
 Mixing and placement of cement.
 Acid etching
 Application of resin bonding
agent.
 Placement of the overlying
composite resin.

60. Lamination with Amalgam
 This combination is likely to be
used in restoration of a molar
teeth that is expected to withstand
a relatively heavy occlusal load.

61. Glass Ionomer Resin-modified
Silicate cement cermet
(Type II) Glass Ionomer
Compressive
strength (24 hr)
180 150 150 105
MPa
26,000 22,000 22,000 15,000
Psi
Diametral tensile
strength (24hr)
3.5 6.6 6.7 20
MPa
500 960 970 2,900
Psi
Hardness (KHN) 70 48 39 40
Pulp response Severe Mild Mild Mild
Anticariogenic Yes Yes Yes Yes
Solubility ( test) 0.7 0.4 - -

62. RECENT ADVANCES IN GLASS
IONOMER CEMENTS
- Highly viscous gic / packable gic/condensable
gic
-Low viscosity gic

63. •
Miracle mix
- Cermet

64. •
- Low ph “smart” materials
- Fluoride charge materials

65. IMPROVED TRADITIONAL GLASS IONOMERS
HIGHLY VISCOUS GLASS IONOMER
Due to the possibility of reduced secondary caries
by fluoride release and to the comparative ease of
use of conventional glass ionomers, further
developments have been made for posterior
restorations in primary and permanent dentition.

66. This material was developed largely as a
response to the need for filling materials in the
atraumatic Restorative Therapy or “ART ”.

67. Ketac Molar (EPSE)---- Powder : Ca, Na, Al
fluorosilicate glass.
The mean particle size is 2.7µm for ART-
Liquid: polycarbonic acid, tartaric acid and water.
Benzoic acid is used as a preservative---- P:L : 2.9:1

68. Uses
 Geriatric and pediatric restorations
 Final restorations (non-stress areas)
 Intermediate restorative (irm)
 Core material
 Long term temporary restoration

69. Advantages of condensable GIC
over conventional GIC
 They are packable and condensable
 They are easy to place
 They are non-sticky
 Early moisture sensitivity is reduced

70.  Rapid finishing can be carried out
 Improved wear resistance.
 Low solubility in oral fluids.

71. DISADVANTAGES OF THESE
GIC’S ARE:
 Due to their opacity, they have esthetic
disadvantages
 They have limited life potential.
 Moderately polishable

72. LOW VISCOCITY GLASS
IONOMERS
• This type of glass ionomer has been developed as
liners, fissure
protecting materials for hypersensitive cervical
areas and endodontic materials.
•Such materials are designed with low powder-
liquid ratios and highly flowable.

73. •These are used as fissure protection materials during the
eruption period of the teeth.

74. METAL – MODIFIED GLASS IONOMER
CEMENTS
 Glass ionomer cements lack toughness and
hence, cannot withstand high-stress
concentrations.
 GIC have been modified by the inclusion of
metal filler particles in an attempt to improve
toughness
 Two methods of modifications have been

75. SILVER ALLOY ADMIX or MIRACLE MIX
• Sced and wilson (1980) found that amalgam alloys
could be incorporated into glass ionomer cements
and that these served to increase the flexure
strength.
• Spherical silver amalgam alloy powder is mixed
with Type II glass ionomer powder in the ratio 7:1.

76. • These systems have been used clinically by
Simmons(1983).
• However, their esthetics are poor –they tend to
impart a gray to blackish colour to the cement –
and they do not take burnish.

77. CERMET – IONOMER CEMENTS:
 In an attempt to improve the abrasion
resistance and strength of GIC,
developed the “cermet”-ionomer.
 These cements, unlike simple mixtures of alloy
particles or metal fibres, contain glass-metal
powders sintered to high density that can be
made to react with polyacids to form a cement.

78. Strength:
The compressive as well as the tensile strength of
the cermet cement is higher than that of the
traditional glass ionomer cement.
Modulus of elasticity:
tends to be relatively lower than the conventional
glass ionomers

79. Abrasion resistance:
The silver cermets materials, where the silver
particles are incorporated in the glass, have more
resistance to abrasion.
Radio opacity:
The silver cermet radiopacity approaches that of
dental

80. Fluoride release:
 Fluoride leaches out from both metal-modified
systems in appreciable amounts.
 Less fluoride is released from the cermet than
from its Type II counterpart.

81. INDICATIONS:
 As an alternative to amalgam in conservative
Class I cavities in primary teeth.
 Core build –up material
 Lining of class II amalgam restorations.
 Root caps for teeth under overdentures
 Preventive restorations and temporary
posterior restorations.

82.  Anterior restorations.
 Areas subjected to high occlusal loading.

83. “Resin –modified glass ionomer materials
that are modified by the inclusion of resin,
generally to make them more photocurable”

84. The powder component of a typical light- cured
material consists of ion leachable glass and
initiators for light or chemical curing or both

85.  The liquid component usually contains water,
polyacrylic acid with or without some
carboxylic acid modified with methacrylate
and Hydroxyethyl methacrylate monomers.
Powder : liquid ratio = 3:1.

86. 1. Translucency and color: Excellence translucency
is seen immediately after light activation.
2. Solubility and disintegration: They appear to be
more resistant to solubility and disintegration
than the auto cure GICs
3. Fluoride release: The light cured GIC liner, in
fact, releases more fluoride

87. 4. Strength: The diametral tensile strength of
RMGIC is higher than that of the conventional.
5. Dimensional change: The RMGIC show a very
small initial shrinkage of the resin component at
the time of light activation.
6. Marginal Adaptation: They exhibit a greater
degree of shrinkage on setting due to
polymerization

88. Adhesion to tooth structure: Bonding mechanism is
similar to conventional GIC
Adhesion to other restorative material:RMGIC are
primarily used as liners and bases although they
also can be used for restorations.
Antibacterial effect: According to articles(DCNA
1998), RMGIC is said to have greater antibacterial
effect than calcium hydroxide.

89.  Can be finished and polished immediately
after set
 Repairs can be carried out, as bond between
old and new material is very strong.
 Exhibits increased adhesion to composite
when used a base

90.  Ideal under composite as it can be etched
immediately
 Fluoride release is greater than conventional
GIC and compomers
 High diametral strength of 20MPa

91. - Biocompatibility is controversial
- Setting shrinkage is higher (-1%) and hence,
microleakage is more and marginal
adaptation is poor
- Lower wear resistance as compared to
composite.

92. USES:
• Used as a liner and base
• Pit and fissure sealant
• Core build-up material

93. A new variety of the usual composite resins
comprising resins and inorganic filler particles is
the polyacid-modified composite resin or
“compomer” which was introduced in the early
1990s.

95. Commercial Products
Compoglass F Principle
Compoglass Flow

96.  Compomer can be defined as a resin composite
with fluoride releasing potential.
 Polyacid – modified glass ionomer cement is
defined as materials that may contain either or
both of the essential components of glass ionomer
cements but at levels insufficient to promote the
acid- base curing reaction in the dark.

97. The compomers presently available contain resins
and fillers common to composite resins and glass
ionomers. They include reactive ion-glass particle
and polymerizable acidic monomers. They are
usually one Component material.

98.  Sealing and filling of occlusal pits and
fissures
 Restorations of primary teeth
 Minimal cavity preparations
 Lining
 Core build-up

99.  Repair of defective margins in restorations
 Restorations of class III cavities
 Restoration of Class V lesions
 Restorations of erosion lesion
 Sealing of root surface for over dentures
 Potential root canal sealers
 Retrograde filing materials in endodontic
surgeries

100. CONTRA INDICATIONS
 Class IV carious lesions
 Lesions involving large areas of labial surface
 Class II carious lesions where conventional
cavities are
prepared
 Lost cusp areas
 Under full metal or PFM crowns where light
cannot penetrate

101. ADVANTAGES
 Superior working characteristics to
RMGIC
 Ease of use
 Easily adapts to the tooth
 Good esthetics

102. TYPE II GIC METAL RESIN
MODIFIED GIC MODIFIED GIC
COMPRESSIVE 150 150 105
STRENGTH(Mpa)
DIAMETRAL 6.6 6.7 20
TENSILE
STRENGTH(MP a)
HARDNESS(KHN) 48 39 40
PULP RESPONSE Mild Mild Mild

103. ANTICARIOGENIC Yes Yes Yes
SOLUBILITY 0.4
FLUORIDE
RELEASE (ug F)
14 days 440 200 1200
30 days 650 300 1600
BOND STRENGTH 1.1-4.5(to <TYPE II 13.4
MPa dentin)

104. DIRECT COMPARISON OF CONVENTIONAL GIC, RMGIC AND COMPOMER
CHARACTERISTIC CONVENTIONAL GIC RESIN MODIFIED POLYACID
GIC MODIFIED GIC
Handling properties/ Powder-liquid Powder – liquid One component
preparation of the systems, aqueous Systems, Water- material, no water
material based; hand-mixed monomer based; and no
versions or hand-mixed or mixing
precapsulated Precapsulated
systems systems
Working time 1-2 minutes Several Unlimited (light
minutes (setting Cured)
initiated by light
curing)
Setting mechanism Acid – base Light curing (40 Light curing only (40
reaction (4-8 minutes), seconds); radical seconds);
second phase within the Polymerisation and Incremental
next 24 hours acid –base reaction technique

105. Moisture sensitivity High, especially Moderate to low None
after placement during first setting
Stage. protective
covering required
Final finish Fair Good Excellent
Adhesion to tooth Self adhesive; Self adhesive;
Structure chemical bond to Primer needed for
enamel and dentin Certain products

106. Strength High compressive High compressive
strength; low Strength; medium
flexural strength flexural strength
Wear resistance Low ; highly Poor
Viscous cements-
Moderate to
acceptable

107. Thank u