The Vietnam Believer Newsletter_MARCH 25, 2024_EN_Vol. 003
GLASS IONOMER CEMENT AND ITS RECENT ADVANCES- by Dr. JAGADEESH KODITYALA
1. Glass ionomer cement & its
recent advances
Jagadeesh k
1st yr p.g
Dept. of conservative dentistry &
endodontcs
G.D.C.H,VIJAYAWADA
3. CONTENTS
• INTRODUCTION
• DEFINITION
• HISTORY
• COMPOSITION
• CLASSIFICATION
• SETTING REACTION
• INDICATIONS
• MODIFICATIONS OF GIC
• RECENT ADVANCES IN GIC
• RFERENCES
4. INTRODUCTION
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)
• Glass ionomer cement is a water based cement
• ADA specification number: 96
5. Definition
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.
6. History
•1965 –A.D Wilson mixed dental silicate glass powder & aqueous
solutions of various organic acids including poly acrylic acid
Set cement is sluggish
Not reported or published.
• The invention of glass ionomer cement was done in 1969.first
reported by Wilson and Kent in 1971.( ASPA I)
• First practical material: ASPA II in1972 by Crisp and Wilson,added
tartaric acid.
• ASPA III- Methyl alcohol was added.
• First marketable material, ASPA IV in 1973
• Luting agent ASPA IVa in 1975 by Crisp and Abel
7. •Metal reinforced cements in 1977 by Sced and Wilson
• Cermet ionomer cements in 1978 by Mc Lean and Glasser
• Improved traslucency, ASPA X by Crisp, Abel,Wilson in 1979
• Water activated cements, ASPA V in 1982 by Prosser et al.
• CLINICAL DEVELOPMENT
• First clinical trials in 1970 by Mc Lean
• Class I restorations, fissure sealing and preventive dentistry
in 1974 by Mc Lean and Wilson
• Erosion lesions, deciduous teeth, lining, composite ionomer
laminates in 1977 by J. W. Mclean & A. D. Wilson.
• Improved clinical techniques between 1976-77 by G.J.Mount
& Makinson,1978
8. • Approximal lesions and minimal cavity preparation in 1980
by Mc Lean
• Water activated luting cements in 1984 by Mc Lean et al
• Tunnel class I and II preparations by Hunt and Knight in 1984
• Double etch ionomer /composite resin laminates,1985,
Mc Lean
9. Other names
• Glass ionomer-term coined by wilson & kent
glass-alumino silicate glass particles
ionomer-poly carboxylic acid.
• ISO terminology- poly alkenoate cement.
• Since its extensive usage to replace the dentin ,has given different
names
Dentin substitute
Man made dentin
Artificial dentin
•Introduced into u.s as ASPA-Alumno silicate polyacrylate
10. Composition
• The glass ionomer powder is an acid soluble calcium fluoroalumino silicate
glass- ion leachable glass.
• Composition of two commercial glass ionomers
Compound Composition A(wt%) Composition B(wt%)
SiO2 41.9 35.2
Al2O3 28.6 20.1
AlF3 1.6 2.4
CaF2 15.6 20.1
NaF 9.3 3.6
AlPO4 3.8 12.8
11. • The raw materials are fused to a uniform glass by heating them to a
temp.of 1100 °C- 1500°C.
• Lanthanum,strontium,barium or zinc oxide additions provide radio
opacity.
• The glass is ground into a powder having particles in the range of 15-50
µm.
•ROLE OF COMPONENTS IN POWDER
•The role of Al2O3 & SiO2 of the glass is crucial and is required to be of
1:2 or more by mass for cement formation.
•CaF2-Supplemented by the addition of cryolite (Na3AIF6).
•This flux
-reduces the temperature at which the glass will fuse
-increases the translucency of the set cement.
12. • Fluoride is an essential constituent which
- Lowers fusion temp., acts as flux
- improves working characteristics & strength
- improves translucency
- improves therapeutic value of the cement by
releasing fluoride over a prolonged period
• Al3PO4-Improves translucency.
Apparently adds body to the cement paste
14. • The liquid is an aqueous solution of polymers
andcopolymers of acrylic acid.
• In most of the current cements,the acid in the form of a
coploymer with itaconic ,maleic ,or tricarboxylic acids.
• polyacrylic acid-is the most important acid contributing to
formation of the cement matrix.
• 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.
15. •Glass ionomer cements are water-based materials
•Plays a role in transporting calcium and aluminium ions to react with
poly acids.
•Types:
- Lossely bound water
-Tightly bound water
•With the aging of cement, the ratio of tightly bound to loosely bound
water increases
•Accompanied by an increase in strength, modulus of elasticity and
decrease in plasticity
•Cement is only stable in an atmosphere of 80% relative humidity
16. • In higher humidities the cement absorbs water and the consequent
hygroscopic expansion can exceed the setting shrinkage.
• Cement can lose water under drying conditions, however leading to
shrinking and crazing.
• Susceptibility to desiccation decreases as the cement ages
• This is prevented if protected for about 10 to 30 mins (depends on
manufacturer).
• 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
17. • 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
Maleic acid
18. • Tartaric acid
• The 5% optically active dextro-isomer of tataric acid is
incorporated.
• It is also hardener that controls the PH of the set cement during
setting process, which in turn controls the rate of dissolution of the
glass.
• It facilitates extraction of ions from the glass.
• It typically increases the working time and also aids in snap test.
19. CLASSIFICATION
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
20. C. ACC.TO CHARACTERISTICS SPECIFIED BY
MANUFACTURER
• Type I --- Luting cement eg. Fuji I, KETAC
• Type II --- Restorative material eg. Ketacfil, Fuji II, fuji IX
• Type III --- a. Bases & liners -- weak with less acidic
b. Bases & liners -- stronger but more acidic
c. Bases & liners -- strong even in thin layer
• Type IV --- Admixture --- eg. Ketac silver, miracle mix
D. ACCORDING TO J.W.McLEAN et al IN 1994
- Glass ionomer cement (traditional)
-Resin modified glass ionomer cement
-Poly acid modified composite resins
21. E. ACCORDING TO INTENDED APPLICATIONS
• 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
22. F. NEWER CLASSIFICATION
• Traditional glass ionomer
a. Type I --- Luting cement
b. Type II --- Restorative cements
c. Type III --- Liners&Bases
• Metal modified Glass Ionomer
a. Miracle mix
b. Cermet cement
• Light cure Glass Ionomer
HEMA added to liquid
• Hybrid Glass Ionomer/resin modified Glass Ionomer
a.Composite resin in which fillers substituted with glass
ionomer particles
b.Precured glasses blended into composites
23. Cement placement
Conditioning the Tooth Surface
• Dentin conditioning prior to placement of a GIC is done primarily
to remove the smear layer.
• GIC is better able to wet the dentin surface.
• Promotes ion exchange.
• Chemically cleans dentin.
• Increases surface energy.
24. Agents used
Surface treatment Time of application(sec)
Citric acid, 50% aq 30
Citric acid, 2% aq/alc 30
Poly (acrylic acid), 25% aq 30
Tannic acid, 25% aq 60
Surface-active solution 60
Dodicin, 0.9% aq 60
Na2EDTA, 2% aq 30
Na2EDTA, 15% aq 30
Sodium flouride, 3% aq 30
Ferric chloride, 2% aq/alc 30
25. Mixing of the cement
Full spoon, no excess
Tip liquid bottle to side, then
invert completely
If water / tartaric acid, only 1 drop
used.
26. 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
27. Loss of gloss/ slump test
GIC --- 60 – 90 sec
Resin-modified GIC --3 – 3.5 min
28. 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
29. Mixing capsules
• To activate capsule apply
pressure 3-4 seconds
before placing in machine
• Ultrahigh speed machine :
4000 cycles/minute
• (< 3000 cycles/minute –
not desirable)
30. Finishing technique
• Best surface –cement allowed to set under matrix
•Carving the cement external to the cavity margins with
sharp knives or scalers
•Finest abrasive should be used to minimize tearing
•Finishing with rotary instruments should be done at
subsequent visit
31. Setting reaction
•1. acid-base reaction
•2. light activated polymerisation
• ACID – BASE REACTION
• GIC formed by the reaction of three materials
Fluoro alumino silicate glass powder
Poly acrylic acid
Water
• An acid – base reaction occurs between the glass powder and
the ionic polymer.
• Water is essential because that is the medium through which
ion transfer takes place
32. • Chemistry of cement forming reaction from initial mixing
occurs in various stages
• The glass particles are attacked at the surface by poly acid which
leads to withdrawal of the cations thus the glass network breaks down
to silicic acid.
• Principally Al3+, Ca2+, F-, are released and migrate into aqueous
phase of cement and form complexes
Decomposition of glass & migration of ions
33. • Initially calcium complexes predominate but later Aluminium
complexes are more.
• pH and viscosity increases
• At critical pH and ionic conc. Precipitation of insoluble poly acrylates
takes place.
• Initial set occurs due to calcium polyacrylate but hardening of cement
is due to slow formation of aluminium polyacrylate
Gelation and vulnerability to water
34. • When cement is not fully hardened Al, Ca, F and polyacrylate ions
may leach out leading to irretrievable loss of cement matrix
• Calcium acrylate is more vulnerable to water. So the
freshly set cements are to be protected.
• This process continues for about 24 hrs
• Undergoes slight expansion and increase in translucency
• Cement becomes resistant to dessication and strength also
increases for at least a year
Hardening and slow maturation
35. •Increase in strength and rigidity are associated with slow increase
in cross linking.
38. Mechanism of adhesion
• Polyalkenoic acid attacks dentine and enamel: displaces PO4,Ca
ions
• Migrate into cement and develop an ion enriched layer firmly
attached to tooth structure.
• The bond strength to enamel is always higher than that to dentin
because of the greater inorganic content & greater homogenity.
39. MECHANISM
• Smith – chelation of calcium(1968)
• Beech –
interaction between apatite and poly acrylic
acid
polyacrylate ions
Ionic bonds with calcium ions in enamel and dentin
40. • Acc. to Wilson(1974)
• Initial adhesion is by hydrogen bonding from free carboxylic
groups
• Progressively these bonds are replaced by ionic bonds
• Polymeric polar chains of acids bridge the interface
between cement and substrate
• Acc. to Wilson, Prosser and Powis(1983)
• Polyacrylate displaces and replaces surface phosphate and
calcium from hydroxyapatite
• An intermediate layer of Ca and Al phosphates and
polyacrylates is formed.
43. •Biocompatibility
• Resistance to plaque because presence of F
• Pulp response to GIC is favorable
• Freshly mixed --- acidic pH 0.9 – 1.6 -- mild inflammation resolve
10 -20 days
* used to protect mech / traumatic exposure of healthy pulp
• Glass ionomer cement showed greater inflammatory response than
ZOE but less than Zn phosphate cement, other cements but it resolved
in 30 days
(Garcia et al, 1981)
44. • The influence of fluoride action is seen of at least 3 mm
around the glass ionomer restoration
• Released for a sustained period of 18 months (Wilson et al
1985)
• Thickly mixed cements release more flouride than thinly
mixed ones.
• Fluoride release is restricted by sodium and to some
extent by calcium content and not the total fluoride content
of the glass.
Fluoride release
45. Fluoride recharge
• Glass ionomers may have synergistic effects when used
with extrinsic fluorides
• In the presence of an inverse fluoride concentration
gradient, glass ionomers may absorb fluoride from the
environment and release it again under specific conditions
• topical APF (acidulated phosphate fluoride), with fluoride
rinses and fluoridated dentifrices recharging takes place
48. • Thermal Properties:
•The thermal diffusivity value of GIC is close to that for
dentin.
• The material has an adequate thermal insulating effect
on the pulp and helps to protect it from thermal trauma
• Solubility & disintegration
lower than ----Zn phosphate
Zn polycarboxylate
In water --- less than Silicate cement
Resin-modified GIC is less resistant to solubility
49. • Compressive strength < silicate cement
• Tensile strength --- higher -- silicates
• Hardness < silicates
• Wear resistance < composites
• ESTHETICS
• Glass ionomer cement has got a degree of translucency
because of its glass filler
• Unlike composite resins, glass ionomer cement will
not be affected by oral fluids
50. • The esthetic quotient depends upon
1.Refractive index of glass particles and matrix
2.Particle size
3.translucency of glass particles
• Specification limits of GIC 0.35 -.90 (for optimum aesthetics
it is between 0.35 – 0.90 )
51. Durability
Affected by the factors
• Inadequate preparation of the cement
• Inadequate protection of restoration
• Variable conditions of mouth
Failure rate is more a measure of clinician’s skill than inherent
quality of the material
• One of the longest observation periods for the conventional
glass ionomers in non-carious cervical lesions showed
retention in the order of 90% after 10 yrs for KetacFil
52. • Some other properties
• Low exothermic reaction
• Adheres chemically to the tooth structure
• Less shrinkage than polymerizing resins
• Dimensional stability at high humidity
• F release discourages microbial infiltration
• Early moisture sensitive --- requires protection
• Poor abrasion resistance
• Average esthetic
53. Indications
• 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.
• Repair of defective margins in restorations
• Minimal cavity preparations – Approximal lesions, Buccal and
Occlusal approach (tunnel preparation)
• Core build-up
54. 2. Fast setting lining cement and bases:
• Lining of all types of cavities where a biological seal and
cariostatic action are required
• replacement of carious dentin the attachment of composite
resins using the acid etch technique
• Sealing and filling of occlusal fissures showing
early signs of caries.
3. Luting cement:
• Fine grain versions of the glass ionomer Cements are used.
• Useful in patients with high caries index
55. Pit & Fissure sealant
• A cariostatic action is essential for caries preventive material
GIC is recommended as a P and F sealant where the orifices
of the fissure are patent .
• 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
56. Core buildup
• 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.
57. Sandwich technique
• Devolped by Mclean,
• To combine the beneficial properties of GIC & composite.
Clinical steps:-
•After cavity preparation,
condition the cavity to develop
good adhesion with GIC.
•Place Type III GIC into prepared
cavity.
•After setting, etch the enamel &
GIC with orthophosphoric acid for
15 seconds.
•This will improve
micromechanical bond to
composite resin.
•Apply a thin layer of low viscosity
dentin bonding agent & finally
place the composite resin over
GIC & light cure it.
58. Advantages
• Polymerisation shrinkage is less,due to reduced bulk
of composite.
• Favorable pulpal response.
• Chemical bond to the tooth.
• Anticariogenic property.
• Better strength,finishing,esthetics of overlying
composite resin.
• Microleakage is reduced
• Minimization of no. of composite increments,
therefore time is saved
59. GIC IN ENDODONTICS
They are used for:
• Sealing root canals orthogradely , retrogradely
• Restoring pulp chamber
• Perforation repair
• Sometimes for repairing vertical fracture
GIC was used because of :
• Its capacity to bond which enhances seal & reinforce the tooth
• Its good bio compatibility, which would minimize irritation to
peri radicular tissues
• Its F release, which imports an anti microbial effect to combat
root canal infection
60. Contra indications
• Class IV carious lesions or 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.
61. Modifications of GIC
Water settable glass ionomer cement :-
• Liquid is delivered in a freeze dried form ,which is
incorporated into the powder.
• Liquid used is clean water.
62. METAL MODIFIED GIC
MIRACLE MIX / SILVER ALLOY ADMIX GIC
• 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%
64. 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 8000C which is ground to fine powder
particle size of 3.5 µm
• 5%titanium dioxide is added to improve aesthetics
• It has excellent handling characteristics
65. Indications
• Core build –up material
• Root caps of teeth under over dentures
• class I cavities in primary teeth
• Lining for class SAF
• Preventive restoration
• Temporary posterior restoration
Contraindications
• Anterior restorations.
• Areas subjected to high occlusal loading
66. PROPERTIES
Strength-
• Both tensile and compressive strength is greater
than conventional glass ionomer cement
Modulus of elasticity-
• tends to be relatively lower than conventional GIC
Abrasion resistance-
• greater than conventional GIC due to silver particle
incorporartion
67. Radiopacity:
silver cermet radio opacity is equal to that of dental
amalgam
Fluoride release
Type II cermet
miracle mix
• 2 weeks 440 ug 200 ug 3350ug
• 1 months 650 ug 300 ug 4040 ug
69. RESIN MODIFIED GLASS IONOMER
CEMENTS
• developed by Antonucci, Mc Kinney and SB Mitra.
• Addition of polymerizable resins to the formulation to import
additional curing process to the original acid base reactions.
Definition: RMGIC can be defined as a hybrid cement that sets via
an acid base reaction and partly via a photo- chemical
polymerization reaction.
Eg:Fuji II LC, Vitrebond, Photac –Fil, Vitremer, FujiV.
70. Composition
• Powder: Ion leachable glass and initiators for light /
chemical / both types of curing
• Liquid : water + Polyacrylic acid modified with MA
and HEMA monomers.
• The HEMA content is around 15-25% and water
content is low to accommodate the polymerizable
ingredients.
• It is a powder : liquid system with P:L = 3:1
71. Setting reaction
2 distinct setting reactions occur
• Acid base neutralization
• Free radicle MA cure. This can occur purely via light
cure or by a combination of LC and chemical cure.
• Thus a cement can be termed
- dual cure if cross linking is via acid base + LC or
- tri cure if its via acid base + Light cure + chemical
cure
73. properties
• Esthetics: According to the Phillips’ science of dental
materials 12th ed, there is a definite improvement in
translucency as the monomer brings the refractive index of
the liquid close to that of the glass particle.
• Fluoride release: is same as that of the conventional
but the lining version shows higher F release
• Strength: The diametrical tensile strength is much
higher but compressive strength and hardness is lesser.
74. • Adhesion: to tooth is reduced. This is expected because of
reduction in carboxylic acid in the liquid and interruption of
chemical bonding due to the resin matrix.
-Adhesion to composites is increased due to the presence of
residual non-polymerized functional groups within the
RMGIC
• Micro leakage: A higher degree of Microleakage is
seen due to polymerization shrinkage
• also due to reduced water and carboxylic acid content and
reduces its wetting capacity
75. • Water sensitivity is considerably reduced.
• The biocompatibility is controversial and precautions
such as placing Ca (OH)2 in deep preparations should
be taken. The transient temp. rise during setting is also a
concern
76. INDICATIONS
• Luting cement esp. in orthodontics
• Liner and base
• Pit and fissure sealant
• Core build up material
• For amalgam repair
ADVANTAGES
• Long Working time and Snap setting
• Early water sensitivity is reduced
• Rapid development of early strength
77. • No etching is needed either to tooth for adhesion or for
the material if composite lamination is to be done.
• Bonding to composite is higher
• Finishing can be done immediately
• F release
• Diametrical tensile strength is higher
• DRAWBACKS
• Of course some drawbacks still need to be
tackled such as
increased shrinkage with concurrent microleakage
Low wear resistance as compared to composites
Its controversial biocompatibility
78. Two-bottle powder liquid system.
Photac Fil Quick Aplicap GC Fuji Plus Capsule Ketac Nano; a paste-paste
system using static mixing.
83. POLYACID MODIFIED RESIN COMPOSITE /
COMPOMER
COMPOMER
FLUORIDE
RELEASING
CAPABILITY
OF GIC
DURABILITY
OF
COMPOSITES
84. COMPOSITION
• Compomers are essentially a one – paste system containing
ion leachable glass & polymerizable acidic monomers with
functional groups of polyacrylic acid & methacrylates in 1
molecule.
• NaF and some other fillers are also present for additional F
release.
• There is no water in the formulation.
• Glass particles are partially silanated to ensure
bonding.
85. SETTING REACTION
Setting reaction occurs in 2 stages
• Stage 1: In contrast to RMGIC, a typical composite resin
network around filler particles forms on light activation
• Stage II : occurs over 2-3 months where by water from
the saliva gets absorbed and initiates a slow acid base
reaction with formation of hydrogels within the resin and
low level fluoride release.
86. • Definition: Compomer can be defined as a material
that contains both the essential components of GIC
but at levels insufficient to promote the acid –base
curing reaction in the dark
• Compomer is a combination of the word ‘comp’ for
composite “omer” for ionomer.
• Though introduced a type of GIC, it became
apparent that terms in of clinical use and
performance it is best considered as a composite
87. PROPERTIES
• ADHESION: to tooth requires acid –etching as acid base reaction
for ion exchange which requires water does not occur for some
time after placement. Bond strengths achieved usually approach
the typical resin bonding systems. It is = 18-24Mpa
• FLUORIDE RELEASE: is limited. It is significantly less than Type II or
RMGIC. F release usually starts after about 2-3 months; it peaks
initially and then falls rapidly
• PHYSICAL PROPERTIES: fracture toughness, flexural strength and
wear resistance are better than GIC but less than composite.
88. INDICATIONS
• P& F sealant
• Restoration of primary teeth, class III and V lesions
along with cervical abrasions and erosions and
intermediate restorations
• Bases for composites, liners
• Small core build ups
• Filling of pot holes & undercuts in old crown
preparations
• Root surface sealing
89. • CONTRAINDICATIONS
• Class IV lesions
• Conventional class II cavities
• Lost cusp areas
• Restorations involving large labial surface
• ADVANTAGES
• Superior working characteristics to RMGIC
• Ease of use
• Easily adapts to the tooth
• Good esthetics
90. • Recently, a 2 component compomer is being marketed as a P: L
system or 2 paste system meant exclusively for luting.
• These are self adhesive due to the presence of water which
starts off the acid base reaction.
• The powder contains the glasses, fluoride & chemical / light
initiators .
• liquid contains the monomers, Poly acrylic acid, water and
activators. These set via light chemical polymer as well acid base
reaction.
91. • To summarize the differences between the three
types of materials:
• Fluoride Release and Rechargability
GICs>RMGICs>PAMCRs
• Wear Resistance
PAMCRs>GICs>RMGICs
• Strength
PAMCRs>RMGICs>GICs
• Ease of Handling
PAMCRs>RMGICs>GICs
• Polishability and Esthetics
PAMCRs>RMGICs>GICs
93. • These are basically, purely chemically activated RMGIC
with no light activation at all.
• Developed mainly for luting purposes, they contain
monomers and chemical initiatiors such a the benzoyl
peroxide and t- amines to allow self polymerization.
• It is used mainly in paediatric dentistry for cementation
of stainless steel crowns,space maintainers, bands and
brackets
Condensable / Self hardening GIC
94. • According to j Leirskar et al 2001, the high viscosity occurs to the
material by adding poly acrylic acid to the powder and finer grain
size distribution.
Advantages over conventional GIC’s
( A Castro & R F Feigal,2001)
• Packable + Condensable
• Easy placement
• Non sticky
• Rapid finishing can be carried out
• Improved wear resistance
• Solubility in oral fluids is very low
95. Indications
• As a final restorative material in class I and Class II primary teeth
• Geriatric restorative material for class I,II,III,IV cavities and cervical
erosion
• Final restorative material in permanent teeth in non stress bearing
areas
• Intermediate restorative material in class I and class II cavities
• Sandwich restoration
• Core build up material
• Fissure sealing material for permanent teeth
97. The low viscosity/flowable GIC –
• For lining, pit and fissure sealing
• endodontic sealers
• for sealing of hypersensitive cervical areas
• These had a low P:L ratio and possessed increase
flow.
eg: Fuji lining LC, Fuji III and IV, Ketac – Endo.
98. 1. Fluoride charged materials: This is a 2 part material
comprising of
• A restorative part and
• A charge part
• The restorative part is used is the usual way. When
the first burst of fluoride is expended, the material is
given a fluoride charge using the second part
99. 2.Low pH “Smart” Material
• developed to enable release fluoride when the
oral pH is low.
• Aptly called “Smart” materials, the F release is
episodic and not continuous which helps to
prolong the therapeutic usefulness of the
material
100. THE BIOACTIVE GLASS
• This idea was developed by Hench and co in 1973.
• It takes into account the fact that on acid dissolution
of glass, there is formation of a layer rich in Ca and
PO4 around the glass
• such a glass can form intimate bioactive bonds with
the bone cells and get fully integrated with the bone.
101. It is being used experimentally as
• Bone cement
• Retrograde filling material
• For perforation repair
• Augmentation of alveolar ridges in edentulous ridges
• implant cementation
• Infra- bony pocket correction
102. FIBER 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
103. 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.
104. GIOMER
• Developed by Shofu
• Giomer utilizes the hybridization of GIC and composite by using a
unique technology called the pre-reacted glass ionomer technology.
• The fluoro aluminosilicate glass is reacted with polyalkenoic acid to yield
a stable phase of GIC this pre reacted glass is then mixed with the resin.
• Depending on the amount of glass which is reacted, the PRG technology
can be 2 types:
F- PRG = reaction of Full / entire glass
S- PRG = Surface of glass
Eg: Beautiful, Reactmer
105. AMALGOMERS
• These are restoratives which are glass ionomer based
but with the strength of amalgam.
• They also provide F- release, natural adhesion to
tooth structure, good compatibility and prevent
shrinkage, creep, corrosion or thermal conductivity
problems associated with other filling materials
• They have been found to have exceptional wear
characteristics, along with other advantages of GIC
106. 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 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 developement
107. CHLORHEXIDINE IMPREGNATED GIC
• To increase the anticariogenic action of GIC
• Still under experimental stage.
• Experiments conducted on cariogenic
organisms
108. PROLINE CONTAINING GLASS IONOMER CEMENT
J Prosthet Dent. 2013 Nov;110(5):408-13. doi:
10.1016/j.prosdent.2013.04.009. Epub 2013
Aug 30.ANSARI et al.
• An amino acid-containing GIC had better surface hardness
properties than commercial Fuji IX GIC.
• This formulation of fast-set glass ionomer showed increased
water sorption without adversely affecting the amount of fluoride
release.
• Considering its biocompatibility, this material shows promise
not only as a dental restorative material but also as a bone
cement with low cytotoxicity
109. CPP – ACP CONTAINING GIC
• Incorporation of casein phosphopeptide-amorphous calcium
phosphate into a glass-ionomer cement.
Mazzaoui SA et al. J DENT RES 2003 NOV 82(11)
• Incorporation of 1.56% w/w CPP-ACP into the GIC significantly
increased microtensile bond strength (33%) and compressive strength
(23%) and significantly enhanced the release of calcium, phosphate,
and fluoride ions at neutral and acidic pH.
• MALDI mass spectrometry also showed casein phosphopeptides from
the CPP-ACP nanocomplexes to be released.
• The release of CPP-ACP and fluoride from the CPP-ACP-containing GIC
was associated with enhanced protection of the adjacent dentin
during acid challenge in vitro.
110. ZIRCONIA CONTAINING GIC
• Scripta Materialia volume 52, issue 2. Y.W. Gu et al.
• Zirconia containing GIC – A potential substitute for miracle mix.
• The diametral tensile strength of zirconia containing GIC significantly
Greater than that of Miracle mix due to better interfacial bonding
Between the particles and matrix.
NANO BIOCERAMIC MODIFIED GIC
• Acta biometerialia volume4 issue2 march 2008 MOSHAVERINIA et al
• Nano hydroxyapaptite / fluorapatite particles added to FUJI II GC
111. • The experimental cements also exhibited higher bond
strength to dentin after 7 and 30 days of storage in distilled
water.
• It was concluded that glass ionomer cements containing
nanobioceramics are promising restorative dental materials
with both improved mechanical properties and improved bond
strength to dentin.
• nanohydroxyapatite/fluoroapatite added cements exhibited
higher compressive strength (177–179 MPa),
higher diametral tensile strength (19–20 MPa) and
higher biaxial flexural strength (26–28 MPa) as compared with
the control group (160 MPa in CS, 14 MPa in DTS and 18 MPa
in biaxial flexural strength).
112. Calcium Aluminate GIC
•A hybrid product with a composition between that of calcium
aluminate and GIC, designed for luting fixed prostheses.
•The calcium aluminate component is made by sintering a mixture
of high-purity Al2O3 and CaO (approximately 1 : 1 molar ratio) to
create monocalcium aluminate.
•The main ingredients in the powder of this hybrid cementare
calcium aluminate, polyacrylic acid, tartaric acid,strontium-fluoro-
alumino-glass, and strontium fluoride. The liquid component
contains 99.6% water and 0.4% additivesfor controlling setting.
•The calcium aluminate contributesto a basic pH during curing,
reduction in microleakage,excellent biocompatibility, and long-term
stability andstrength.
114. • References
• Glass ionomer cement by Alan D.Wilson and John W. Mclean
• Philips science of dental materials, 11th ed & 12th ed
• Sturdevant’s Art and science of operative dentistry, Fifth edition
• Craig’s Restorative dental materials, Twelfth edition
• G J Mount and R W Hume Text book of Minimal intervention dentistry
• Advances in Glass ionomer cement , Carel L. Davidson, J Minim Interv
Dent 2009; 2 (1)
• Clinical evaluation of glass-ionomer Cement restorations, Martin John
TYAS J Appl Oral Sci. 2006;14(sp.issue):10-3
• Scripta Materialia volume 52, issue 2. Y.W. Gu et al
• Acta biometerialia volume4 issue2 march 2008 MOSHAVERINIA et al