DENTISTRY

1. GLASS IONOMER
CEMENTS

2. CONTENTS
 INTRODUCTION
 DEFINITION
 HISTORY
 CLASSIFICATIONS
 COMPOSITION
 SETTING REACTION
 PROPERTIES
 CLINICAL PROCEDURES
 INDICATIONS and CONTRAINDICATIONS
 RECENT ADVANCES
 CONCLUSION

3. INTRODUCTION
• Since its extensiveusageto replacethe
dentin ,hasgiven different names
Dentin substitute
Man made dentin
Artificial dentin

4. Glass ionomer cements are tooth-
colored materials that bond
chemically to dental hard tissues
and release fluoride for a relatively
long period.
They have therefore been
suggested as the materials of
choice for the restoration of carious
primary teeth.

5.  DEFINITION of cement:
- A cement is a substance that hardens to act as
a base , liner , filling material or adhesive to bind
devices or prosthesis to the tooth structure or to
each other.
- philips’ science of dental
materials (12th
ed)
 GIC:
- Water based material that hardens following an
acid base reaction between basic
fluoroaluminosilicate glass and an aqueous solution
of polyacids. (Anusavice)

6. HISTORICAL BACKGROUND
 The search for improved materials initiated numeroussearch for improved materials initiated numerous
developments, such that by the 1920s three main, such that by the 1920s three main
categories of cements had become established: zinccategories of cements had become established: zinc
phosphate cements, zinc oxide eugenol cements, andphosphate cements, zinc oxide eugenol cements, and
silicate cements.silicate cements.
 In 1966, D.C. Smith introduced yet another class of
cement, in which the liquid of the zinc phosphate cement
was replaced by aqueous polyacrylic acid. This so-called
carboxylate cement opened up new prospects for self-
adhesive dental materials.

7.  On the basis of these developments, Wilson et al.
introduced glass ionomer cementing materials in 1969,
a material class which remains very successful today.
 The first glass ionomer cement product, ASPA
(Alumino-Silicate-Poly-Acrylate), introduced in the
1970s, was formulated by adding polyacrylic acid as
the liquid component to finely ground silicate pow

8.  Invention of glass ionomer cement in 1969 Wilson &
Kent.
 Term to glass ionomer cement was coined by B.E
Kent.
 1972 Wilson & Crisp found that tartaric acid
improves manipulative properties
 1974 Mc. Lean & Wilson proposed clinical use of
GIC.

9. CLASSIFICATIONS
 Philips
 Type I - Luting
 Type II - Restorative
 Type III - Liner & base
 Davidson / Mjor
 Conventional / Traditional GIC
 Resin Modified GIC
 Polyacid Modified Resin Composites

10. MOUNT:
A) Glass Ionomer Cements
(i) Glass Polyalkeonates
(ii) Glass Polyphosphates
B) Resin modified GIC
C) Polyacid modified composite resin
D)
 Auto Cure
 Dual Cure
 Triple Cure
E)
 Type I
 Type II
- Type II 1 (AESTHETIC)
- Type II 2 (RESTORATIVE)
 Type III

11. Sturdvent
1.Conventional or Traditional
2. Metal Modified GIC
- Miracle Mix
- Cermet
3. Light Cured GIC
4. Hybrid (resin modified) GIC
5. Polyacid Modified Resin Composites
Mc Lean and Nicholson
 Glass ionomer cements
 Poly alkeonates
 Poly phosphonates
 Resin modified GIC
 Poly acid modified GIC

12.  According to clinical use as:
Type I- Luting
TYPE II- Restorative
Type III- Liner/ Base
Type IV- Pit & Fissure Sealant
Type V- Luting for Orthodontic Purpose
Type VI- Core build up material
Type VII- High fluoride releasing command
set
Type VIII- ART
Type IX- Geriatric & Paediatric GIC

13. COMPOSITION
POWDER (Calcium Fluroaluminosilicate)
 ALUMINA (28.6%) Alumina: Silica --> 1:2
 SILICA (41.9%)
 FLUORIDE
 CALCIUM FLUORIDE (15.7%)
 ALUMINIUM PHOSPHATE (3.8%)
 CRYOLITE
 Na+
, K+
, Ca2+
 La2O3, SrO

14. Liquid:
Originally was 40 to 50% aqueous solution of
polyacrylic acid.
Current cements the acid is in the form of
copolymer with
Maleic, Increase the reactivity of liquid
Itaconic, Decrease the viscosity
Tricarboxylic Reduce the tendency for
gelatin
Tartaric acid improves the handling
characteristics & increase working time, but
shortens the setting time.

15. FUNCTIONS OF
COMPONENTS :
POWDER Alumina :
 It forms the skeletal structure of the glass. It also
increases the opacity of the glass.
 Silica :
 It forms the skeletal structure of the glass and increases
the transparency of the glass
 Aluminium Fluoride :
 It partially replaces silicon in the glass network providing
negative sites, which are vulnerable to acid attack by H+
leading to decomposition of glass and providing cement
potential.

16.  Fluoride :
 It contributes to therapeutic value by releasing fluoride over a
prolonged period of time. It helps to lower the fusion temperature.
It enhances translucency and improves the working characteristics.
It also helps to increase the strength of set cement
 Calcium Fluoride :
 It acts as a flux and provides opacity to the set cement
 Phosphate :
 It lowers the melting temperature and modifies the setting
characteristics of the cement.
 Lanthanum, Strontium, Barium :
 It provides radio - opacity to the cement
 Aluminum phosphate :
 It helps to add body to cement and improve the translucency of
the cement

17. LIQUID
 The liquid is an aqueous solution of
polymers and copolymers of acrylic
acid.
 A copolymer is a chain consisting of
two
molecules.
 polyacrylic acid, is the most
important acid contributing to
formation of the cement matrix .

18. Itaconic acid
 Itaconic acid promotes reactivity between
the glass and the liquid.
 It also prevents gelation of the liquid which
can result from hydrogen bonding
between two polyacrylic acid chains

19. Polymaleic acid
 a stronger acid than polyacrylic acid
 causes the cement to harden and lose
its moisture sensitivity faster.
 more carboxyl (COOH) groups which
lead to more rapid polycarboxylate
crosslinking

20. Tartaric acid
 a reaction controlling additive .
 it extends the working time.
 promotes a snap set.
 Strengthens and hardens the cement.

21. • Water-
• 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.

22. Mixing of the cement
Full spoon, no excess
Tip liquid bottle to side, then
invert completely
If water / tartaric acid, only 1
drop used.

23. Liquid should not stay on paper pad
longer than 1minute (some of it may
soak into it)
Don’t mix beyond 30 seconds
The objective is – only wet the particle –
no dissolving it.
First half folded into liquid in 10-15seconds
Second half incorporated in 15 seconds
Small mixing area
Mixing

24. Manipulation consideration for
GIC:
 To achieve long lasting restoration and retentive fixed
prostheses, the following condition for GIC must be
satisfied:
 The surface of prepared tooth must be clean and dry
 Consistency of mixed cement must allow complete
coating of surface irregularities and complete sealing of
prostheses.
 Excess cement must be removed at appropriate time.
 Surface must be finished without excessive drying
 Protection of restoration be ensured.
 These conditions are similar for luting applications
except that no surface finishing is needed.

25.  The powder and liquid should not be dispersed on
slab until just before mixing procedure is begun; as
prolonged exposure to office atmosphere alters the
precise acid: water ratio of liquid.
 The powder is incorporated into liquid with stiff,
spatula. The mixing time should not exceed 45-60s.
At this time mix should have a glossy appearance
which indicates residual polyacid
 Prolonged mixing leads to dull surface and
adhesion will not be achieved.
 GIC are also supplied in capsule containing
preproportioned powder and liquid. Mixing is
accomplished in an amalgamator after the seal that
separates the powder and liquid is broken. Capsule
also contains a nozzle for placement.

26. Working time & setting time
• It sets rapidly in the mouth that is within 3-5 min
and hardens to form a body having translucency
that matches enamel
• Setting time for type I –GIC – 5 -7 min
• Setting time for type II–GIC --10 min
• Film thickness should not exceed 20µm for luting
agents

27. STAGES OF THE SETTING
REACTION OF GLASS
IONOMER CEMENTS

28.  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.

29.  Stage1: Dissolution:
 At the beginning of the reaction the surface
of the glass particles is attacked by the
polyacid.
 This results in the dissolution of the glass
particles releasing calcium and aluminium ions
leading to the formination of the cement sol

30.  Stage2: Precipitation of Salts, Gelation and Hardening:
 During this stage calcium and aluminum ions bind
to polycarboxylate groups. The initial set is achieved
by cross-linking of the more readily available calcium
ions with the carboxyl of the acid.
 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.
 Maturation occurs over the next 24 hours as the less
mobile aluminium ions become bound within the
cement matrix, leading to more rigid cross lining
between the poly (alkenoic acid) chains.
 Fluoride and phosphate ions donot particpate in the
crosslinking of the cement the unreacted portions of
the glass particles are sheated by the silica gel which
developes during the removal of the cations friom the
surface of the particles.

31.  Stage 3: Hydration of Salts:
 Associated with the maturation
phase is a progressive hydration of
the matrix salts, leading to sharp
improvement in the physical
properties

32.  *) Factors affecting the setting mechanism:
 Glass Composition: Higher the
alumima/Silica ratio, faster the set and
shorter the W.T.
 Powder particle size: The finer the powder,
faster the set and shorter the W.T.
 Addition of Tartaric acid sharpens the set
without reduction in W.T.
 Temperature of mix: Increase the
temperature, faster the set and shorter the
W.T.
 Relative proportion of constituent in the mix:
The greater proportion of glass and lower the
proportion of H2O; faster the set and shorter
the W.T

33. INDICATIONS AND CONTRAINDICATIONS:
 Indications:
 Restorative Materials:
 Restoration of erosive/abrasive lesions without cavity
preparation.
 Sealing and filling of occlusal pit and fissures
 Restoration of primary teeth.
 Restoration of Class V carious lesions.
 Restoration of Class III carious lesions, preferably using
lingual approach.
 Repair of defective margins in restorations
 Minimal cavity preparations in approximal lesions
through buccal and occlusal approach (tunnel
preparations)

34. Contraindications for Use:
 Class IV carious lesions (or) fractured incisors
 Lesions involving large areas of labial enamel
where esthetics is of major importance.
 Class II carious lesion where conventional
cavities are prepared, for replacement of
existing amalgam restorations.
 Lost cusp areas.

35. PROPERTIES
 Mechanical Properties:
 Strength: Glass Ionomer cements lacks sufficient
strength. Improving its strength is clearly desirable and
progress is being made through several approaches.
 Mechanical mixing using capsules containing pre
proportioned amounts of the components will
statistically improve the performance of any Glass
Ionomer Cement.
 The strength of Glass Ionomer cement is increased as
the filer content is increased and the water content is
reduced.
 However increased strength is accompanied by an
acceleration of setting and loss of workability.

36. Compressive Strength:
 Glass Ionomer compressive strength is 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.
 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.


37. PHYSICAL PROPERTIES:
 Biocompatibility:
 The biocompatibility of Glass-ionomer
cements with the living tissues is a subject of
importance because the glass Ionomer cements
have to be in direct contact with dentin because
they were designed to adhere to tooth
materials by molecular bonding.
 The adhesion to tooth material endures that
they provide an excellent and enduring
marginal seal, thus eliminating secondary
caries.
 Sustained release of fluoride confers resistance
to caries on adjacent tooth material.

38. Fluoride Release:
 The prolonged and substantial release of fluoride
ions from all glass Ionomer cements is of major clinical
significance.
 Fluoride ions released from the restorative materials
become incorporated in hydroxyapatite crystals of
adjacent tooth structure to from to 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.
 Thickly mixed cements used for restorations release
more fluoride than thinly mixed ones used for luting
because they contain proportionately more glasses and
hence more fluoride.

39. 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.

40. Fluoride release

41. Sandwich techinque
 The sandwich technique is developed by mclean to
combine the benifical properties of gic and
composite .presentely is called as bilayered or laminate
techinque, it is done in large class 3 , classs 5 class4.
 Clinical steps: After cavity preparation condition the
cavity to develop adhension with glassinomer
 Fast setting type 3glassinnomer cement is used to
replace the lost dentin in sufficent bulk,
 either autocured or resin modified glassinommer
used.glass inomer is placed subgingivally.
 Once it has set ,cut back to expose the enamel margins
and allow enough bulk for composite
 Etch enamel ad autocure gic for 15 sec using phosporic
acid , this improes micromechinal bond to composite
resins

42.  Etching is not done for resin modified gic ,when they
are used etch enamel alone for 15 sec.
 Wash and gentle dry
 Apply enamel bonding agent ad gic base ad light cure
for 20 sec processed the composite resin buildup
 Advantages : flouride nfrom gic minimizes recurrent
caries.
 Favourable pulpal responses due to biocompatibility of
gic
 Better strength
 excellent subgingival responses
 Disadvantages: time consuming
 Techinque sensitive

43. Tunnel preparation
 It first described by jiks in 1963 as a
conservative alternative class 2 cavity
preparation in primary molars.
 later hunt modifies the technique for
restoring small proximal caries using
glassionomercement in deciduous and
permanent teeth

44. Clinical technique :
Following rubber dam Isolation access is gained to the
proximal caries through the occlusal aspect.
 Using a no.2 round but in a high speed handplece, the
preparation is started 2mm away from the marginal
ridge on the involved side.
 A “tunnel” is prepared diagonally under the marginal
ridge into the proximal carious dentin.
 Removal of the carious dentin can be done using a
no.2 round bur in a slow speed hand piece.
 Since access is limited loupes and caries disclosing
dyes are valuable aid s in verifying whether the caries
is completely removed during restoration sectional
matrix band is adapted and wedge is placed cermet
cement is usually used for these cavities

46. Tunnel restorations
 Indications : patients with high
esthetic demands and low caries
rate who exhbit small proximal
caries without involving marginal
ridges
 Contraindications: large proximal
caries involving marginal ridges
 Difficulty in access
 Marginal ridges subjected to high
occlusal loads

47. Tunnel restorations Advantages:
 Conservative
 Conservative preparation allos easy retention of
restoration.
 Less time consuming than tradition Cl II preparation
 Less traumatizing to pulp
 Maintenance of intact MR.
 Minimal esthetic change to tooth.
 Is considered not to alter interarch/Intra-arch
relations.
 Disadvantages:
 Difficulty in complete caries removal
 Collapse of MR or enamel wall may occur

48. ART Techinque
 Modem restorative dentistry requirres electrically
powered equipment to perform various procedures.
Unfortunately, basic restorative procedures such as
restoring carious lesions are not possible in developing
countries especially in remote areas due to the lack of
infrastructure to provide water, electricity and
equipment.
 In such areas, the atraumatic restorative treatment
(ART) technique has proved to be a valuable method to
retain as many teeth as possible under these adverse
circumstances.
 The ART technique was first evaluated in Tanzania in
the mid 19805 and since then has become popular in
several parts of the world.

49.  The ART technique consists of a simplified
approach to caries management. Hand
instruments are used to excavate the soft caries
followed by restoring the cavities with the
acutocure gic.
 Indications : occlusal piit and fissure cavities of
small to moderate sizes with adequate tooth
structure to surroujnd the restoration
 Physically or mentally handicapped patients

50. Clinical procedure
 Teeth are isolated with cotton rolls
 Undermined enamel is broken away using hand instruments such
as hatchets.
 Caries is excavated using spoon excavators.
 A highly viscous glass ionomer cement is placed into the cavity
and pressed by means of a gloved finger to fill the adjacent pits
and fissure also
 Occlusion is checked and excess material is removed before it
hardens.
 The restoration is finally coated with vasaline or petroleum jelly.
 Advantages :max preserving tooth structure ,minimal
intervention procedure, lowcost, minimal discomfort,
gic{biocompatiability ,fluoride release}
 Disadvantages: hand fatigue during instrumentationlack of
proper access

51. RECENT ADVANCES
IN
GIC

52. HIGH VISCOSITY GIC
Developed as an alternative to amalgam.
Packable / condensable glass ionomer cements
Composition: Powder: Ca,,Al fluorosilicate glass
Liquid: PA,TA,water and benzoic acid
INDICATIONS: Molar restoration of primary teeth
Intermediate restoration
Core build up material
For A R T
ADVANTAGES: Packable or condensable
Improved wear resistance
Easy to use
Low solubility
Rapid finishing possible
Decrease moisture sensitivity
DISADVANTAGES: Limited life
Moderately polishable
Not esthetic
.

53. LOW VISCOSITY GIC
1. Also called as Flowable GIC
2. Low P:L ratio thus increase flow.
3. Use for lining, pit and fisure sealer, endodontic
sealer and for sealing hyper sensitive cervical
area.
Eg fuji lining LC, Ketac – endo etc.
Fuji lining LC Ketac-Endo

54. CERMET
Cermet: this is formed by fusing the glass
powder to the fine precious metal powders
like silver or gold through sintering .
MIRACLE MIX:
1 Seed & Wilson (1980) invented miracle mix
2 Spherical silver amalgam alloy+ G I C in
ratio 1:7,and mixing it with GIC liqiuid
Improves strength and abrasion resistance of
the cement

55. Indications: Class I cavities in primary teeth
Core build up material
Lining of class II amalgam restorations
Root caps for teeth under over dentures
As a preventive restoration
Contraindications: Anterior restoration
In areas of high occlusal loading
Advantages:
Ease for placement
Adhesion to tooth structure and anticariogenic
potential
Crown cutting can be done immediately
Increased wear resistance
Disadvantages:
Esthetically poor
Tooth discoloration
Rough surface

56. Miracle mix
COMMERCIAL PRODUCTS
Ketac Silver

57. RESIN MODIFIED GIC
Objective:
To overcome low early strength and moisture sensitivity
1. Defined as hybrid cement that sets partly by acid base
reaction and partly by polymerisation reaction (Mc
Lean)
2. Powder – Ion leachable glass and initiators
liquid – water, Poly acrylic acid, HEMA (15-25%),
methacrylate monomers.

58. Advantages
 Long working time due to photo curing
 Improved setting characteristics
 Decrease sensitivity to water (but not significantly,
Journal of Conservative Dentistry, June 2005)
 Increase early strength
 Finishing & polishing can be done immediately
 Improved tensile strength.
 Better adhesion to composite restoration
 Increase fluoride release.
 Repairable.

59. Disadvantage
 Biocompatibility is controversial
 More setting shrinkage leading increase
microleakage and poor marginal adaptation

60. POLYACID MODIFIED COMPOSITE
RESIN
 Also called as compomer
 Defined as : material that contain both the
essential components of GIC but in an
amount insufficient to carry out acid base
reaction in dark.
 They are developed to combine fluoride
release of GIC and durability of composite

61.  Composition: one paste system containing ion
leach able glass, sodium fluoride, polyacid
modified monomer but no water
 Recently 2 paste or powder liquid system is
introduced.
 Powder:
 Strontium aluminium flurosilicate glass particles, metal
oxides,and intiators
 Liquid:
 Polymerizable methacrylate/caboxylic acidic monomers
multi functional acrylate monomers and water ;

62.  Setting reaction
1. Initially light curing forms resin network
around the glass
2. After 2 to 3 month there is water uptake
which initiates slow acid base reaction and
fluoride release.

63. Properties
 Adhesion –Micromechanical, absence of
water thus no self adhesion
 Fluoride release minimal.
 Physical properties better than conventional
GIC but less than composite.
 Optical properties superior to conventional
GIC.

64. Indications
 Pit and fissure sealant
 Restoration of primary teeth
 Liners and bases
 Core build up material
 For class III & V lesions
 Cervical erosion / abrasion
 Repair of defective margins in restorations
 Sealing of root surfaces for over dentures
 Reterograde filling material.

65. Contraindications
 Class IV carious lesions
 Large areas of labial surfaces
 Class II cavities where conventional cavity
is prepared
 Lost cusp areas
 Under full crown or PFM crowns.

66. Advantages
 Ease of use
 Easy adaptation to the tooth
 Good esthetics
 More working time than RM GIC

67. Commercial Products
Compoglass F Principle
Compoglass Flow

68. Fiber-reinforced Glass Ionomer
Cements
 Al and Sio2 fibers added to glass powder,polymer
rigid inorganic matrix material (PRIMM)
 Diameter of fiber is 2µm.
 Advantages:
 Increased wear resistance.
 Improved handling characteristics
 Increased depth of cure
 Reduction of polymerization shrinkage
 Improved flexure strength(50Mpa)

69. GIOMERS
 True hybridization of GIC and composite
 Combine fluoride release and fluoride
recharge of GIC with esthetic easy
polishability and strength of composite
 Based on PRG technique.
 Two types:
 S- PRG :Reaction of entire glass
 S-PRG: Reaction with glass surface

70. INDICATIONS
 Class I, II, III, IV, and Class V cavities
 Restoration of cervical erosion and Root caries
 Laminates and core build up
 Restoration of primary teeth.
 Repair of fracture of porcelain and composites

71. Advantages
 Increase wear resistance
 Increase Radiopacity (glass filler)
 Ideal shade match (improved light diffusion and
fluorescence)
 High and sustained fluoride release and recharge
 Provide almost complete seal against bacterial
microleakage
 Little mechanical and chemical pulp irritation
 Inhibit demineralization

72. Example
BEAUTIFUL (SHOFU)

73. CONCLUSION
 GIC’s have come a long ways since its modest
beginning in 1969. Even though research can boast
of substantial improvements, certain essential
properties still seem to be wanting and further clinical
trials are warranted for a majority of these
developments. At this point of time, we are left
wondering if GIC will ever be able to dominate
tomorrow’s restorative scene or will it go into total
oblivion. Who knows? Only the future will tell. Let us
wish GIC all the best for the coming years.

74. References
 Skinner’sSciencesof dental materials--- Ralph
W. Phillips--- 9th
Edition
 Phillips’ Sciencesof dental materials---- 11th
Edition
 Restoration & Prevention of Tooth Structure---
Graham J. mount ; W R. Hume
 Browning WD. Thebenefitsof glassionomer
self-adhesivematerialsin restorativedentistry.
Compend Contin Educ Dent 2006
May;27(5):308-14
 operativedentitry----vimal k sikri