seminar gic n recent advances
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CONTENTS
INTRODUCTION
COMPOSITION
CLASSIFICATION
MANIPULATION OF THE MATERIAL
SETTING MECHANISM
APPLICATION OF MATERIAL & USES
ADVANTAGES & DISADVANTAGES
PROPERTIES
MODIFICATIONS & ADVANCEMENT IN MATERIAL
CONCLUSION
REFERENCES
your name
1955
1952
1968
1972
KVAMER
MC LEAN
BUONOCORE
SMITH
WILSON &
KENT
your name
What is unusual of GIC???
It is neither purely organic nor purely
inorganic
It is neither a polymer nor a hydraulic
cement but set by chemical gelation
It is a kind of composite but where the
filler has taken part in the reaction
Has porcelain like translucency, adhere to
tooth structure
Shown promise as bone cement
Evolved as a hybrid from silicate & Polycarboxylate cement
DEFINITION: DEFINITION: A cement that consists of a basic glass & an acidic polymer which sets A cement that consists of a basic glass & an acidic polymer which sets
by an acid-base reaction between these components. by an acid-base reaction between these components. Mclean & Wilson 1994)Mclean & Wilson 1994)
Glass Ionomer: "glass" refers to the glassy ceramic particles and the
glassy matrix (non-crystalline) of the set material, while "ionomer" refers to
ion crosslinked polymer.
2. Polyalkenoic or Polyalkenoate: refers to polymer chain which
incorporates alkenoic monomers such as acrylic acid, tartartic acid, maleic
acid, etc.
Liquid :
Polyacrylaic acid – 45%
Itaconic acid – 5%
Maleic acid – 5%
Tricarballylic acid – 5%
Tartaric acid – Traces (increases working
time and decreases setting time)
Water – 50% (Hydrates reaction product)
MODIFICATIONS IN POWDERMODIFICATIONS IN POWDER
A)Anhydrous GIC - dried polyacrylic acid
B)Miracle mix – Silver tin alloy
C)Silver-palladium / Titanium alloy – CERMET cement
D)Light, Dual, Tricure GIC – BisGMA, TEGDMA and HEMA
MODIFICATIONS IN LIQUIDMODIFICATIONS IN LIQUID
A)Anhydrous cement – only water and tartaric acid
B)Light cure composite – HEMA
C)Amino-acid modified
1.Powder and liquid (with different shades)
2.Pre-proportioned capsule (for mixing with mechanical mixers)
3.Powder (anhydrous GIC which can be mixed with water)
4.Two pastes (mixed and light cured)
5.Single Paste (Compomers) as tubes or compules (Cavifils)
Microsyringe for
dispensing liquid
DISPENSING
A)According to Wilson and McLean in 1988
1.Type I – Luting cements
2.Type II – Restorative cements
a.Restorative aesthetic
b.Restorative reinforced
B) According to application
1.1.Type I – Luting cements
2.2. Type II – Restorative cements
•Aesthetic filling materials
•Reinforced materials
3.3. Type III – Lining cement
4.4. Type IV – Fissure sealant
5.5. Type V – Orthodontic cement
6.6. Type VI – Core build up cement
7.Type VII- Intermediate Restorations
8.Type VIII- ART(ANT. restoration)
9.Type IX –ART( POST. restoration )
C. Newer Classification
1.Traditional Glass Ionomer
a.Type I – Luting cement
b. Type II – Restorative Cements
c. Type III – Liners and Bases
2. Metal Modified Glass Ionomer
a.Miracle mix
b.Cermet cement
3. Light cure glass ionomer
HEMA added to liquid
4. Hybrid Glass Ionomer
a. Pre-cured glasses blended into composites
D. According to McLean et al in 1994
1.Glass Ionomer Cements (Traditional)
2. Resin Modified Glass Ionomer Cements.
3. Poly Acid Modified Composite Resins.
E. According to manufactures GC fuji
Fuji I - Luting
Fuji II - Restorative
Fuji III - Fissure protection
Fuji lining - Liner
Fuji Ortho- Ortho bonding
Fuji 8 - Ant. Esthetic ART
Fuji IX - ART (high strength)
Fuji IX GP - Condensable G.I.C.
GC Miracle MIX
The most accepted classification - The most accepted classification - Graham Mount in Graham Mount in
1994.1994.
based on the composition, based on the composition,
powder/liquid ratio powder/liquid ratio
clinical applications of the material.clinical applications of the material.
Type IType I - - Luting GICLuting GIC
fine powderfine powder particle size particle size
used for used for luting crowns, luting crowns,
bridges, inlays and bridges, inlays and
orthodontic appliancesorthodontic appliances
Low Powder/Liquid ratio - 1.5 : 1Low Powder/Liquid ratio - 1.5 : 1
Film thickness - < 20 micro mmFilm thickness - < 20 micro mm
Type I GIC’s - CementationType I GIC’s - Cementation
Ketac-CemKetac-Cem
Fuji IFuji I
Type II - Restorative glass ionomerType II - Restorative glass ionomer cementcement
Type II.1 - Type II.1 - Restorative Restorative estheticesthetic glass ionomer cement – glass ionomer cement –
used for esthetic restorations. used for esthetic restorations.
high powder/liquidhigh powder/liquid ratio, ratio, 3:1 or3:1 or greater greater
has superior physical properties and good translucency. has superior physical properties and good translucency.
autocured autocured
resin-modified cementsresin-modified cements
Type II.2 -Type II.2 - Restorative Restorative reinforced reinforced glass ionomer glass ionomer
cement – cement –
have metallic inclusions for reinforcement.have metallic inclusions for reinforcement.
superior strength but lack esthetics. superior strength but lack esthetics.
used where improved physical properties used where improved physical properties
are required but esthetics is not important.are required but esthetics is not important.
Powder/Liquid ratio - Powder/Liquid ratio - 3: 13: 1 or greater. or greater.
Core buildup Core buildup
rootcariesrootcaries
tunnel restoratointunnel restoratoin
deciduous restorationdeciduous restoration
Type II GIC’s – Restoratives
• Ketac-Fil
• Chem-Fil
Type III -Type III -Lining or base glass ionomer cementLining or base glass ionomer cement
In low powder liquid ratio as lining;In low powder liquid ratio as lining;
in high powder liquid ratio as base beneath amalgam, in high powder liquid ratio as base beneath amalgam,
composite restorations.composite restorations.
Powder/Liquid ratio - Powder/Liquid ratio - 1.5:1 (lining).1.5:1 (lining).
3:1 or greater (base).3:1 or greater (base).
Auto cured Auto cured
or resin-modifiedor resin-modified..
DISPENSING AND MANIPULATIONDISPENSING AND MANIPULATION
Available commercially in two forms:Available commercially in two forms:
1) Powder and liquid for 1) Powder and liquid for hand mixing.hand mixing.
2) Pre-proportioned capsules for 2) Pre-proportioned capsules for mechanical mixing.mechanical mixing.
1) Hand mixing:1) Hand mixing:
Great care required - Great care required - proper powder-liquid ratioproper powder-liquid ratio. .
manufacturer's instructions - followedmanufacturer's instructions - followed
Mixing - on a cool, dry glasss lab or a paper pad using a thin-Mixing - on a cool, dry glasss lab or a paper pad using a thin-
bladed plastic spatula. bladed plastic spatula.
main objective of mixing - main objective of mixing - wet the surface of each glass wet the surface of each glass
particle with the liquidparticle with the liquid, without dissolving the powder , without dissolving the powder
completely in the liquid.completely in the liquid.
Glass ionomer powder
and liquid dispensed
Powder divided into two halves
Incorporation of the first
increment of the powder gently but gently but
rapidly rolling the powder into the rapidly rolling the powder into the
liquidliquid
Completed mix
first half- within 10 seconds first half- within 10 seconds
second half- within 15 secondssecond half- within 15 seconds
Mixing- within 25-30 secondsMixing- within 25-30 seconds
finished mix 'glossy wet' on the surfacefinished mix 'glossy wet' on the surface
working time for the mixed cement - 1-2 minutes.working time for the mixed cement - 1-2 minutes.
2) Mechanical mixing:2) Mechanical mixing:
pre-proportioned capsules - consistent powder-liquid ratio,pre-proportioned capsules - consistent powder-liquid ratio,
mechanical mixing in an amalgamator ensuresmechanical mixing in an amalgamator ensures
- standardized mixing and setting times. - standardized mixing and setting times.
The material - syringed into the cavity and exhibits The material - syringed into the cavity and exhibits
optimum physical properties. optimum physical properties.
Check the efficiency of your machineCheck the efficiency of your machine
by Assessing the by Assessing the 'loss of gloss'loss of gloss' '
of a freshly mixed capsule.of a freshly mixed capsule.
Determining the loss of glossDetermining the loss of gloss/ SLUMP TEST/ SLUMP TEST
SETTING SETTING
REACTIONREACTION
ACID-BASE REACTIONACID-BASE REACTION
It occurs between the glass powder and ionic polymerIt occurs between the glass powder and ionic polymer
The setting reaction of Glass ionomer cements involves three The setting reaction of Glass ionomer cements involves three
overlapping stages.overlapping stages.
Stage1:Stage1: DissolutionDissolution
Stage2:Stage2: Precipitation of salt, gelation and hardeningPrecipitation of salt, gelation and hardening
Stage3:Stage3: Hydration of salts.Hydration of salts.
GIC is formed by reaction of 3 materialGIC is formed by reaction of 3 material
1.1.Fluoro alumino silicate glass powderFluoro alumino silicate glass powder
2.2.An ionic polymer of polyacrylic acidAn ionic polymer of polyacrylic acid
3.3.WaterWater
It can be set by acid base reaction or light cure polymerisation
DECOMPOSITION-
of the glass & release of cement
forming metal ions
MIGRATION
of these metal ions
in to the aqueous phase.
GELATION
Of the polyacid by the
metal ions leading to set
POST SET HARDENING
1 hr -24 hrs
FURTHER SLOW
MATURATION
>24 hrs
Crisp et al(1974) & Barry et al (1979)
Cook (1982)
GIC
SiO2 Al203 CaF2
Glasses - fusing the components between Glasses - fusing the components between 11001100°°C to 1500C to 1500°°CC
pouring the melt onto a metal plate or into waterpouring the melt onto a metal plate or into water
then ground to a fine powder for mixing with polyacid.then ground to a fine powder for mixing with polyacid.
Glasses - silica - Glasses - silica - transparenttransparent
glasses - CaF2 or alumina - glasses - CaF2 or alumina - opaque.opaque.
Calcium fluoride (CaF2)Calcium fluoride (CaF2) and and Cryolite (Na3AlF6) - Cryolite (Na3AlF6) -
flux. flux.
lower the temperature of fusionlower the temperature of fusion
improve the working characteristicsimprove the working characteristics
increases the strength increases the strength
contributes to therapeutic value of cement (F releasecontributes to therapeutic value of cement (F release) )
Aluminium Phosphate (AlPO4)Aluminium Phosphate (AlPO4)
improves translucency improves translucency
adds body to the cement paste.adds body to the cement paste.
Strontium / Barium / LanthanumStrontium / Barium / Lanthanum
may wholly or partly replace calcium to give a may wholly or partly replace calcium to give a radiopaque radiopaque
glass.glass.
Polyelectrolytes –Polyelectrolytes –
as the name implies are both as the name implies are both electrolytes and polymers. electrolytes and polymers.
The more important carboxylic acids in the ionomer system The more important carboxylic acids in the ionomer system
include include
ACRYLIC ACID, ACRYLIC ACID,
MALEIC ACIDMALEIC ACID
ITACONIC ACIDITACONIC ACID
either in the form of a either in the form of a conc. aqueous solution (40% to 50% by conc. aqueous solution (40% to 50% by
mass)mass) or blended dry with either water or an aqueous solution or blended dry with either water or an aqueous solution
of tartaric acidof tartaric acid. [Mclean et al, 1984]. [Mclean et al, 1984]
WaterWater - the REACTION MEDIUM and also plays a role in - the REACTION MEDIUM and also plays a role in
hydrating reaction products.hydrating reaction products.
Tartaric acidTartaric acid
DECREASES viscosity & DELAYING gelationDECREASES viscosity & DELAYING gelation
greater the concentration greater is the delay. greater the concentration greater is the delay.
[Cook, 1983; Hill and Wilson; 1986].[Cook, 1983; Hill and Wilson; 1986].
Prolongs W.T of mixProlongs W.T of mix
Decrase S.T Decrase S.T
INCREASES handling charactersticsINCREASES handling characterstics
MOA MOA ::
Temporary suppresionTemporary suppresion of ionization of polyacid of ionization of polyacid
Enhances extraction of Al fromEnhances extraction of Al from Glass. Glass.
Fully hardened GIC - Fully hardened GIC - all ions in an insoluble formall ions in an insoluble form. .
no longer vulnerable to attack by moisture.no longer vulnerable to attack by moisture.
Hardening continues for about 24 hoursHardening continues for about 24 hours, during which time , during which time
translucency develops as the chemical reaction proceeds translucency develops as the chemical reaction proceeds
SLOW MATURATION Continues even after 24 hours; SLOW MATURATION Continues even after 24 hours;
in the first few days in the first few days
-translucency develops further;-translucency develops further;
-increase resistance to dessication-increase resistance to dessication
-increase resistance to acid attack-increase resistance to acid attack
- cement becomes more rigid and gathers strength - cement becomes more rigid and gathers strength
THE ROLE OF WATER
The GIC are water-based cements. The GIC are water-based cements.
FUNCTIONSFUNCTIONS
It is reaction medium.It is reaction medium.
It serves to hydrate the siliceous hydrogel and the metal salts formed.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 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.desiccation while it is setting, the cement-forming reactions will stop.
As a plasticizerAs a plasticizer
Water content in set cement Water content in set cement 11-24% 11-24%
Cement is stable only in an atmosphere of Cement is stable only in an atmosphere of 80%80% relative humidity relative humidity
(Hornsby 1980) (Hornsby 1980)
Water present in set cement can be classified
into two forms:
(1) Loosely bound water (readily removed by
dessication)
(2) Tightly bound water (Cannot be removed)
[Wilson and Crisp, 1975; Elliot et
al,1975; Wilson et al, 1981]
As the cement ages, degree of hydration (ratio of As the cement ages, degree of hydration (ratio of
tightly bound to loosely bound water) increases. This tightly bound to loosely bound water) increases. This
is accompanied by an increase in strength and is accompanied by an increase in strength and
modulus and a decrease in plasticity.modulus and a decrease in plasticity.
[Paddoson and Wilson, 1976; Wilson et al, 1981][Paddoson and Wilson, 1976; Wilson et al, 1981]
When subjected to dessication : Loss of water When subjected to dessication : Loss of water
(1) Shrinking and crazing(1) Shrinking and crazing
(2) Retardation of cement formation(2) Retardation of cement formation
(3) Weaker cement(3) Weaker cement
When subjected to moisture : Absorption of When subjected to moisture : Absorption of
water water
(1) Disruption of surface by swelling(1) Disruption of surface by swelling
(2) Loss of substance to oral environment(2) Loss of substance to oral environment
[Wilson et al, 1981; [Wilson et al, 1981;
Causton, 1981; Roulet and Walti, 1984; Phillips and Causton, 1981; Roulet and Walti, 1984; Phillips and
Bishop; 1984]Bishop; 1984]
This problem does not arise --- This problem does not arise ---
if GIC -- protected for if GIC -- protected for between 10 and 30 minutesbetween 10 and 30 minutes..
MOST EFFECTIVE MATERIALS FOR MOST EFFECTIVE MATERIALS FOR
PROTECTING GICSPROTECTING GICS
Low viscosity, light curing bonding agentsLow viscosity, light curing bonding agents..
Proprietary varnishesProprietary varnishes supplied by manufacturers supplied by manufacturers
Wax / petroleum jellyWax / petroleum jelly
only afford brief protection only afford brief protection
(as they are Easily Washed (as they are Easily Washed
Off by tongue movements)Off by tongue movements)
[Earl & Coworkers, 1985][Earl & Coworkers, 1985]
GIC after 30 min without protection
ISOLATION.
TOOTH PREPARATION .
MECHANICAL PREPARATION
CHEMICAL PREPARATION.
CEMENT PLACEMENT .
MIXING OF THE CEMENT.
RESTORATION.
SURFACE PROTECTION .
FINISHING & POLISHING .
CLINICAL PROCEDURES FOR PLACEMENT:
To ensure the successful use of glass ionomers 3
parameters that must be controlled are:
- Conditioning of the tooth surface
- Proper manipulation
- Protection of the cement during setting
ISOLATIONISOLATION
SHADE SELECTION
Excessive dehydration is unnecessary
Cotton rolls and retraction cord are enough
TOOTH PREPARATION
CONDITIONING OF THE SURFACE CONDITIONING OF THE SURFACE
WITH 25% POLYACRYLIC ACID WITH 25% POLYACRYLIC ACID
CLEANING WITH SLURRY OF CLEANING WITH SLURRY OF
PUMICE AND WATERPUMICE AND WATER
PREPARATION OF THE MATERIAL
Mouldable soft cervical
bands
Matrix is tucked under the
gingival margin GIC is injected
under the matrix
Matrix burnished closely to the
cavity margins to avoid excess
cement.
Light – curing bonding resin
applied immediately after
lifting the matrix .
Scalers / excavators are used to trim the
margin. Avoid using rotary instruments.
Do not destroy the bulk of the filling ,
but confine the finishing to the margins.
At a later visits these surfaces can
polished with soft abrasive rubber cups
and a slurry of fine – grained alumina.
PRE OPERATIVE
VIEW
POST OPERATIVE
VIEW
Polishing cups and points,
Finishing and polishing discs
Graded fine diamond
polishing stone
GIC POLISHING KIT
Dr. Shashikiran N. D, Nisha Madhavan and Subba Reddy V. V
Compared and evaluated, the rise in pulpal temperature during the
finishing and polishing of composite resin.RmGIC and
Compomer restoration at 4 different speeds (10,000 and 20,000 rpm)
with coolant and (5,000 and 6,000 rpm) without coolant
Concluded that
1.It is not advisable to do dry polishing for any restoration materials
2. If needed it should be done with intermittent pressure and at low
speeds less than 5,000 rpm
3. Polishing done with high speed above 5,000rpm can be done using
coolant and with intermittent pressure
RUBBER DAM
I)Useful in protecting the unset cement from moisture
II)Damaging effect once the cement has set
MATRICES
Varnish
Petroleum jelly
Copal varnish or clear nail varnish
Light cured bonding agent - best solution
PROTECTION of GIC RESTORATION
INSTRUCTIONS
Powder or liquid supplied by different manufacturers
Should never be interchanged – results in altering the
physical properties
Both powder and liquid bottles should firmly closed at
all times and stoppers should be replaced immediately
after dispensing.
Clean up procedure
Liquid should never stored in refrigerator
Make sure mixing slab is not below dew point before dispensing powder
1) Restoration of permanent teeth :
Class V and Class III cavities
Abrasion / Erosion lesion
Root caries
2) Restoration of deciduous teeth
Class I cavities
Rampant caries, nursing bottle caries
3) Luting or cementing
Metal restorations - inlays, onlays, crowns
Non-metal restorations - composite inlays and onlays
Veneers
Pins and posts
Orthodontic bands and brackets
4) Preventive restorations
Tunnel preparation
Pit and fissure sealant
5) Protective liner under composite and amalgam
6) Core build up
7) Splinting of periodontally weak teeth
8) Other restorative technique
Layered restorations/ Laminated restorations /
Bilayered restorations
Atraumatic restorative treatment (Fuji VIII and Fuji
IX).
Bonded restorations
9) Endodontics
10) Temporizing a broken tooth - J Am Dent Assoc – 2000;131(2)
ApplicationsApplications
EROSION / ABRASION LESIONSEROSION / ABRASION LESIONS
CLASS III CARIESCLASS III CARIES
MINIMAL CAVITY PREPARATIONSMINIMAL CAVITY PREPARATIONS
CLASS V CARIOUS LESIONSCLASS V CARIOUS LESIONS
Pits and fissures (Fuji III)Pits and fissures (Fuji III)
Bracket BondingBracket Bonding
GLASS IONOMER AS LINER AND BASEGLASS IONOMER AS LINER AND BASE
Glass-ionomer cement as a lining.
Glass-ionomer cement as a base.
Restoration of root caries in Geriatic patientsRestoration of root caries in Geriatic patients
USE IN ENDODONTICSUSE IN ENDODONTICS
WHY used in endodonticsWHY used in endodontics
1. Capacity to bond to dental tissues- enhance the seal & 1. Capacity to bond to dental tissues- enhance the seal &
reinforce the toothreinforce the tooth
2. Long term F- release- impart an antimicrobial effect 2. Long term F- release- impart an antimicrobial effect
to combat root canal infectionto combat root canal infection
3. Biocompatible – minimise irritation of periradicular 3. Biocompatible – minimise irritation of periradicular
tissuetissue
ROOT CANAL SEALINGROOT CANAL SEALING
RETROGRADE ROOT CANAL FILLINGRETROGRADE ROOT CANAL FILLING
PERFORATION REPAIRPERFORATION REPAIR
TREATMENT OF VERTICAL FRACTURESTREATMENT OF VERTICAL FRACTURES
CORONAL SEALING AFTER ROOT CANAL CORONAL SEALING AFTER ROOT CANAL
TREATMENT TREATMENT
V. V Subba reddy, Rafi Ahmed Tagoo
Conducted a study to assess the retrograde root sealing ability of 3 GIC
Ie., cermet, conventional, Light cure GIC
Concluded- Light cured GIC showed better apical seal than other two
GLASS IONOMER CEMENTS IN ENDODONTICS
(1). Ketac-endo strengthens endodontically treated roots (1). Ketac-endo strengthens endodontically treated roots
and may be used for weaker roots which are likely to and may be used for weaker roots which are likely to
be susceptible to vertical root #.be susceptible to vertical root #.
[J. Endod; 2002; Mar ; 28 (3); 217-9][J. Endod; 2002; Mar ; 28 (3); 217-9]
(2) While comparing apical leakage between ketac endo (2) While comparing apical leakage between ketac endo
and grossman sealer, the best results were noted when and grossman sealer, the best results were noted when
ketac endo sealers were used with lateral ketac endo sealers were used with lateral
condensation.condensation.
[Oral Surg oral Med Oral Pathol; 1994 : Dec; 78)[Oral Surg oral Med Oral Pathol; 1994 : Dec; 78)
(3) Vitrebond has a potential as root-end filling material as the (3) Vitrebond has a potential as root-end filling material as the
tissue response is more favourable than that to amalgam tissue response is more favourable than that to amalgam ..
[ Int. Endod J. 1997, Mar, 30 (2); 102-14] [ Int. Endod J. 1997, Mar, 30 (2); 102-14]
(4) Teeth without intraorifice barrier leaked significantly more (4) Teeth without intraorifice barrier leaked significantly more
than teeth with vitrebond intraorifice barriersthan teeth with vitrebond intraorifice barriers. .
[J. Endod; 1999 Sep; 25(9)][J. Endod; 1999 Sep; 25(9)]
(5) MTA alone or vitremer in combination with collagen (5) MTA alone or vitremer in combination with collagen
sponge can be used effectively in the treatment of sponge can be used effectively in the treatment of
perforations in a furcation areaperforations in a furcation area..
[Int. Dent. J. ; 2005 Jun; 55 (3)][Int. Dent. J. ; 2005 Jun; 55 (3)]
Biocompatibility of furcal perforation repair material Biocompatibility of furcal perforation repair material
using cell culture technique: Ketac Molar versus using cell culture technique: Ketac Molar versus
ProRoot MTA. ProRoot MTA.
percent of cell viability in the Ketac Molar group was percent of cell viability in the Ketac Molar group was
lower than in the ProRoot MTA lower than in the ProRoot MTA
more cytotoxic to the PDL cells than MTA more cytotoxic to the PDL cells than MTA
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Dec;102(6):e48-50. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Dec;102(6):e48-50.
Epub 2006 Sep 26. Epub 2006 Sep 26.
comparison of sealing capabilities of amalgam, GIC comparison of sealing capabilities of amalgam, GIC
and zinc oxide eugenol cement when used as retro and zinc oxide eugenol cement when used as retro
grade filling materials (in vitro study). grade filling materials (in vitro study).
GIC is just as effective as Amalgam as a retro-sealer GIC is just as effective as Amalgam as a retro-sealer
ZnO2E cement showed poor sealing abilities ZnO2E cement showed poor sealing abilities
J Ayub Med Coll Abbottabad. 2003 Jul-Sep;15(3):43-6. J Ayub Med Coll Abbottabad. 2003 Jul-Sep;15(3):43-6.
Sandwich TechniqueSandwich Technique
DOUBLE – LAMINATED TECNIQUE or BILAYERED DOUBLE – LAMINATED TECNIQUE or BILAYERED
TECHNIQUE TECHNIQUE
Bonding composite resins to GICs.Bonding composite resins to GICs.
First described by First described by McLean and Wilson (1977).McLean and Wilson (1977).
GIC - replace carious dentin prior to attachment of composite GIC - replace carious dentin prior to attachment of composite
resins to etched enamel.resins to etched enamel.
The laminate restoration - decrease microleakage compared to The laminate restoration - decrease microleakage compared to
simple composite restoration. simple composite restoration.
clinically employed while restoring large Class III, Class IV, clinically employed while restoring large Class III, Class IV,
Class V, Class I and Class II cavities with direct composite Class V, Class I and Class II cavities with direct composite
resinsresins
TYPES:-TYPES:-
1.1. Open sandwich technique Open sandwich technique- proximal box is first filled with - proximal box is first filled with
GIC and the occlusal restoration is completed with composite GIC and the occlusal restoration is completed with composite
resin.resin.
2.2.Closed sandwich techniqueClosed sandwich technique- in this the cavity is first - in this the cavity is first
completely filled with GIC. The restored tooth is then completely filled with GIC. The restored tooth is then
reprepared ,leaving a thick glass ionomer base and creating reprepared ,leaving a thick glass ionomer base and creating
sufficient space to make a resin composite sufficient space to make a resin composite
DELAYED SANDWICH TECHNIQUE OR CERVICAL DELAYED SANDWICH TECHNIQUE OR CERVICAL
LINING TECHNIQUELINING TECHNIQUE
THIN TRANSPARENT LAYER OF COMPOSITE IS
APPLIED TOWARD THE PROXIMAL SURFACE OF
MATRIX TO MODIFY THE ORIGINAL CLASSII
CAVITY TO CLASSI
A. Introduction:A. Introduction:
1.1.Historical Development Historical Development
a. ART materials designed as temporary restorations for a. ART materials designed as temporary restorations for
3rd world countries3rd world countries
b. Goals = caries control, replacing missing tooth b. Goals = caries control, replacing missing tooth
structure, functionstructure, function
c. First tested in central African countriesc. First tested in central African countries
d. Currently used in SE Asia, India, and Africa --- but d. Currently used in SE Asia, India, and Africa --- but
also in 1st and 2nd worldalso in 1st and 2nd world
ATRAUMATIC RESTORATIVE
TECHNIQUE (A.R.T. or ART)
2. Definition: 2. Definition:
ART = approach includes both prevention and treatment of ART = approach includes both prevention and treatment of
dental caries.dental caries.
based on excavating and removing caries using hand based on excavating and removing caries using hand
instruments only and then restoring the tooth with an instruments only and then restoring the tooth with an
adhesive filling material (glass - ionomer).adhesive filling material (glass - ionomer).
3. Excellent success as a temporary restorative material3. Excellent success as a temporary restorative material
Commercial Examples:Commercial Examples:
Fuji IX (GC)Fuji IX (GC)
Fuji VIII(GC)Fuji VIII(GC)
Occlusal pit and
fissure caries in
mandibular first
molar
Caries
excavation
using spoon
excavator
Completed caries excavation
Cement placed
and protected with gloved finger
Excess cement
removed using carver
Completed restoration
GEFFERY KNIGHT CO-CURING GEFFERY KNIGHT CO-CURING
TECHNIQUETECHNIQUE
simultaneous curing of unpolymerised composite resin and simultaneous curing of unpolymerised composite resin and
inactivated LC GIC. inactivated LC GIC.
Composite resin cures before the GIC. Composite resin cures before the GIC.
Polymerisation shrinkage of the resinPolymerisation shrinkage of the resin may be taken up by the may be taken up by the
uncured GIC,uncured GIC,
reducing the internal stress of restoration.reducing the internal stress of restoration.
(Quintessence international 1994; 25-2; 97-100)(Quintessence international 1994; 25-2; 97-100)
The co-cured RMGIC bonding system eliminates several The co-cured RMGIC bonding system eliminates several
placement steps and produces a significantly stronger placement steps and produces a significantly stronger
chemical bond between GIC and composite resin than the 'etch chemical bond between GIC and composite resin than the 'etch
and bond' technique. and bond' technique.
RMGIC bond and composite resin may be co-cured to GIC RMGIC bond and composite resin may be co-cured to GIC
either before or after initial set has occurred.either before or after initial set has occurred.
Aust Dent J. 2006 Jun;51(2):175-9Aust Dent J. 2006 Jun;51(2):175-9. .
DIS
CONTRAINDICATIONCONTRAINDICATION
1) In stress bearing areas1) In stress bearing areas - in stress bearing areas like - in stress bearing areas like
Class I, Class II and Class IV cavities as they lack Class I, Class II and Class IV cavities as they lack
fracture toughness.fracture toughness.
2) Labial buildups2) Labial buildups - When large areas of labial enamel - When large areas of labial enamel
in anterior teeth to replacedin anterior teeth to replaced
- discolouration, abrasion or fractures- discolouration, abrasion or fractures,,
3) Cuspal coverage3) Cuspal coverage - not suited for cuspal replacement - not suited for cuspal replacement
lack of strength, rigidity and fracture toughness.lack of strength, rigidity and fracture toughness.
4) In mouth-breathers4) In mouth-breathers - avoided in mouth-breathers and - avoided in mouth-breathers and
patients with xerostomia patients with xerostomia
as the restorations become opaque, brittle and as the restorations become opaque, brittle and
disintegrate over a short period of time.disintegrate over a short period of time.
Advantages
&
Disadvantages
Adhesive property Adhesive property
No retention features are No retention features are
required required
Esthetic restorative material Esthetic restorative material
Liberates fluoride that is Liberates fluoride that is
anticariogenic anticariogenic
Biocompatible Biocompatible
Low oral solubility Low oral solubility
Easy to manipulate Easy to manipulate
Easily available Easily available
Permanent restorative Permanent restorative
material material
1) Low fracture resistance -
weak and lack rigidity than composite resins
and amalgam.
have a low modulus of elasticity.
2) Low wear resistance - exhibit low resistance to
wear when compared to composite resins.
3) Colour – Autocured glass ionomer cements not
as esthetic as composite resins.
4) Sensitivity to moisture soon after setting-
STRENGTH :STRENGTH :
a)a)COMPRESSIVE STRENGTH : COMPRESSIVE STRENGTH : 150 – 200 MPa. Increased by 150 – 200 MPa. Increased by
increasing alumina content but at the expense of translucency.increasing alumina content but at the expense of translucency.
b)b)TENSILE STRENGTH : TENSILE STRENGTH : 6.5 - 17.4 MPa . Higher tensile strength 6.5 - 17.4 MPa . Higher tensile strength
compared to silicates.compared to silicates.
c)c)FLEXURAL STRENGTH : FLEXURAL STRENGTH : 15 - 20 MPa .15 - 20 MPa .
HARDNESS : HARDNESS : 48 KHN.48 KHN.
FRACTURE TOUGHNESS : FRACTURE TOUGHNESS : MUCH INFERIOR TO COMPOSITE.MUCH INFERIOR TO COMPOSITE.
WORKING TIME: 45-60 secWORKING TIME: 45-60 sec
SETTING TIME : 3-5 minSETTING TIME : 3-5 min
MECHANICAL PROPERTIES
ADHESION
Important property of GICImportant property of GIC
Allows conservative approachAllows conservative approach
Provide a perfect sealProvide a perfect seal
It bond chemically to enamel It bond chemically to enamel
and dentin and dentin
General requirement for adhesionGeneral requirement for adhesion
1.1.Good substrate wettingGood substrate wetting
2.2.Low contact angleLow contact angle
3.3.Clean substrateClean substrate
4.4.Surface tension of liquid must be less than enamel.Surface tension of liquid must be less than enamel.
Mount 1991, Ngo 1997:Mount 1991, Ngo 1997:
PHYSICAL PROPERTIES
MECHANISM OF ADHESION TO ENAMEL & DENTINMECHANISM OF ADHESION TO ENAMEL & DENTIN
Bonding of GIC to tooth structure - CHEMICAL one and not a Bonding of GIC to tooth structure - CHEMICAL one and not a
MECHANICAL one.MECHANICAL one.
The PRINCIPAL mode of adhesion being BONDING TO The PRINCIPAL mode of adhesion being BONDING TO
HYDROXYAPATITEHYDROXYAPATITE
VARIOUS THEORIES PROPOSEDVARIOUS THEORIES PROPOSED : :
(1)(1)Chelation of Ca2+ contained in hydroxyapatite is Chelation of Ca2+ contained in hydroxyapatite is
responsible for adhesion.responsible for adhesion.
[Smith, 1968].[Smith, 1968].
(2) Hydroxyapatite + Polyacrylic acid (2) Hydroxyapatite + Polyacrylic acid POLYACRYLATE IONS POLYACRYLATE IONS
made strong ionic bonds with Ca2+ of hydroxyapatite in enamel and made strong ionic bonds with Ca2+ of hydroxyapatite in enamel and
dentin. dentin. [Beech, 1973][Beech, 1973]
The polyalkenoic acid component of the glass ionomer - attack the The polyalkenoic acid component of the glass ionomer - attack the
tooth surfacetooth surface
releasing calcium and releasing calcium and
phosphate ions. phosphate ions.
ions are then combined into the surface layer of the glass ionomerions are then combined into the surface layer of the glass ionomer
to form an intermediate layer described as the to form an intermediate layer described as the
'interdiffusion zone', ion-enriched layer'interdiffusion zone', ion-enriched layer..
which is firmly attached to both the tooth surface and the glass which is firmly attached to both the tooth surface and the glass
ionomerionomer
The chemical bonding- calcium phosphate-poly acrylate The chemical bonding- calcium phosphate-poly acrylate
crystalline structure formed at the interface between enamel or crystalline structure formed at the interface between enamel or
dentin and the set cementdentin and the set cement
diffusion based adhesiondiffusion based adhesion
This zone forms the basis of an extremely strongThis zone forms the basis of an extremely strong
adhesive bond between glass ionomer and theadhesive bond between glass ionomer and the
tooth.tooth.
This bond - dynamic as a reversible breaking and reforming This bond - dynamic as a reversible breaking and reforming
of calcium carboxyl complexes occurs in the presence of of calcium carboxyl complexes occurs in the presence of
water.water.
BARRIERS TO ADHESIONBARRIERS TO ADHESION
(1) (1) WaterWater- DENTINAL FLUID and loosely and tightly - DENTINAL FLUID and loosely and tightly
bound water in the surface of enamel.bound water in the surface of enamel.
2) 2) Dynamic nature of toothDynamic nature of tooth -Because enamel is an ion -Because enamel is an ion
exchanger and dentine is a living material subject to exchanger and dentine is a living material subject to
change change
IMPROVING ADHESIONIMPROVING ADHESION
surface conditioners improve BOND STRENGTH.surface conditioners improve BOND STRENGTH.
main mechanismmain mechanism - to smoothen both enamel and - to smoothen both enamel and
dentin irregularities dentin irregularities
to prevent air entrapment and to minimise sites where to prevent air entrapment and to minimise sites where
stress concentration can occur.stress concentration can occur.
Ideal requirementsIdeal requirements of surface conditioners (MOUNT1984) of surface conditioners (MOUNT1984)
(1) Isotonic (1) Isotonic
(2) pH : 5.5 to 8.0(2) pH : 5.5 to 8.0
(3) Non-toxic (3) Non-toxic
(4) Compatible with cement(4) Compatible with cement
(5) Water soluble & Easily removable (5) Water soluble & Easily removable
(6) Not deplete enamel / dentin chemically(6) Not deplete enamel / dentin chemically
(7) Enhance the surface chemically to increase bonding.(7) Enhance the surface chemically to increase bonding.
Various agentsVarious agents used : used :
(1) Surface active microbicidal solution(1) Surface active microbicidal solution
(2) Poly (acrylic) acid 10%(2) Poly (acrylic) acid 10%
(3) Tannic acid 25%(3) Tannic acid 25%
(4) FeCl2(4) FeCl2
(5) NaF(5) NaF
(6) Mineralising solution-((6) Mineralising solution-(developed by both Causton and developed by both Causton and
JohnsonJohnson1979, 1982)1979, 1982)
(7) EDTA 10%(7) EDTA 10%
(8) 10% Citric acid(8) 10% Citric acid
(9) 3% Hydrogen peroxide.(9) 3% Hydrogen peroxide.
pretreatment of the surface -pretreatment of the surface -McLean and Wilson McLean and Wilson (1977) (1977)
first used the term surfacefirst used the term surface conditioning for this treatment conditioning for this treatment
Rough tooth surfaces are Rough tooth surfaces are contraindicated.contraindicated.
In general, “the smoother the surface the stronger the bond", In general, “the smoother the surface the stronger the bond",
(Powis et aI., 1982; Aboush and Jenkins, 1986)(Powis et aI., 1982; Aboush and Jenkins, 1986)
Recommended use :Recommended use :
25% solution of poly (acrylic acid) – 10 secs for surface 25% solution of poly (acrylic acid) – 10 secs for surface
conditioning of cavities ( conditioning of cavities ( Powis et al. (1982)Powis et al. (1982)
Currently 10% PAA FOR 10 SEC – MOST Currently 10% PAA FOR 10 SEC – MOST
WIDELY ACCEPTEDWIDELY ACCEPTED
(b) 25% tannic acid – 30 sec ; for preparation with large areas of (b) 25% tannic acid – 30 sec ; for preparation with large areas of
dentindentin
The most common mode of failure in the The most common mode of failure in the adhesion adhesion
between a GIC and the dentinbetween a GIC and the dentin during microtensile during microtensile
bond strength tests is bond strength tests is cohesive failurecohesive failure within the GIC within the GIC
((Tanumiharja Tanumiharja et al.,et al., 2000 2000
microtensile bond strengths of a GIC and an RMGIC microtensile bond strengths of a GIC and an RMGIC
to to carious dentin were significantly lowercarious dentin were significantly lower than those than those
to sound dentinto sound dentin
the mean microtensile bond strengths of RMGIC to the mean microtensile bond strengths of RMGIC to
both sound and carious dentin were significantly both sound and carious dentin were significantly
higher than those of GIC higher than those of GIC
In sound dentinIn sound dentin - - cohesivecohesive failure in GIC pre- failure in GIC pre-
dominant; dominant;
in carious dentin-in carious dentin- mixed failuremixed failure predominant predominant
Oper Dent. 2006 Sep-Oct;31(5):590-7 Oper Dent. 2006 Sep-Oct;31(5):590-7
AdvantagesAdvantages
lowers the surface energy of the tooth lowers the surface energy of the tooth
increasing the wettability ion exchange adhesion by increasing the wettability ion exchange adhesion by
GIC GIC
removes the smear layer while retaining the smear removes the smear layer while retaining the smear
plugs. .plugs. .
Being part of the glass ionomer system any residues Being part of the glass ionomer system any residues
left over will not interfere with the setting reaction of left over will not interfere with the setting reaction of
the cement.the cement.
Fluoride content in cementFluoride content in cement
Forsten (1993)Forsten (1993)
What does fluoride do???What does fluoride do???
Increased enamel resistance/ reduction in enamel Increased enamel resistance/ reduction in enamel
solubilitysolubility
Increased rate of posteruptive maturationIncreased rate of posteruptive maturation
Remineralisation of incipient lesions/ caries inhibition Remineralisation of incipient lesions/ caries inhibition
zoneszones
Fluoride as an inhibitor of demineralizationFluoride as an inhibitor of demineralization
Interference with microorganismsInterference with microorganisms
ANTICARIOGENICITY
FLUORIDE RELEASE AND FLUORIDE RELEASE AND
RECHARGEABILITRECHARGEABILIT YY
GIC have a cariostatic action. GIC have a cariostatic action.
spread of caries is arrested at restoration / cavity wall margin spread of caries is arrested at restoration / cavity wall margin
F- originates from the fluoride used in preparing F- originates from the fluoride used in preparing
aluminosilicate glasses (CaF, Na3AlF6aluminosilicate glasses (CaF, Na3AlF6) [Kent et al 1976]) [Kent et al 1976]
This F- is released as NaF [Wilson and Coworkers, 1985] This F- is released as NaF [Wilson and Coworkers, 1985]
and also as CaF2and also as CaF2
[Powis and Wilson, 1987[Powis and Wilson, 1987
F- is mainly leached as a sodium salt, which is not a F- is mainly leached as a sodium salt, which is not a
matrix-forming species. Thus, loss of F- does not matrix-forming species. Thus, loss of F- does not
weaken the cement weaken the cement
F- is released by DIFFUSION MECHANISM where F- is released by DIFFUSION MECHANISM where
the rate of release is proportional to the square root of the rate of release is proportional to the square root of
time time ..[Wilson et al 1985; Kuhn and Wilson, 1985][Wilson et al 1985; Kuhn and Wilson, 1985]
is released for a sustained period of time – at least is released for a sustained period of time – at least
18 months.18 months.
Thickly mixed cements release more F- than thinly Thickly mixed cements release more F- than thinly
mixedmixed. [Meryon and Smith, 1984]. [Meryon and Smith, 1984]
MECHANISM OF ACTION OF F-MECHANISM OF ACTION OF F-
(1) F- is taken up by enamel apatite to form (1) F- is taken up by enamel apatite to form
flurohydroxyapatite at enamel surface. This flurohydroxyapatite at enamel surface. This resistance to resistance to
plaque acidsplaque acids. [Brundevold et al, 1967; McLundie and Murray, 1972; Muhler . [Brundevold et al, 1967; McLundie and Murray, 1972; Muhler
1956; Moreno et al, 1977]. 1956; Moreno et al, 1977].
2) F- 2) F- ¯¯ surface energy of apatite thereby surface energy of apatite thereby ¯¯ the the
adherence of dental plaque to tooth surface. adherence of dental plaque to tooth surface.
[Glantz 1969][Glantz 1969]
(3) F- aids in remineralisation of damaged enamel (3) F- aids in remineralisation of damaged enamel
[Silverstone, 1978][Silverstone, 1978]
(4) F- changes the composition of bacterial plaque (4) F- changes the composition of bacterial plaque
which alters the carbohydrate metabolism of dental which alters the carbohydrate metabolism of dental
plaque plaque [Horowitz et al, 1977; Silverstone, 1978; Mellberg, 1977; [Horowitz et al, 1977; Silverstone, 1978; Mellberg, 1977;
Ingram and Nash, 1980].Ingram and Nash, 1980].
A fluoride enriched tooth surface has a critical pH of A fluoride enriched tooth surface has a critical pH of
4.5. 4.5.
Fluoride ReleaseFluoride Release
a. Decreases dramatically after 24-72 hrsa. Decreases dramatically after 24-72 hrs
b. Decreasing release for first month; Low b. Decreasing release for first month; Low
release for 1-6 monthsrelease for 1-6 months
FLUORIDE RELEASE
Re-charging strategies:Re-charging strategies:
1. Use daily fluoride rinses to provide F source for re-1. Use daily fluoride rinses to provide F source for re-
chargingcharging
2. Use F toothpastes for re-charging2. Use F toothpastes for re-charging
3. Use topical fluorides for re-charging3. Use topical fluorides for re-charging
coating of 10% AgF on GICs and a resin modified GIC greatly coating of 10% AgF on GICs and a resin modified GIC greatly
enhanced the concentration of fluoride released from these enhanced the concentration of fluoride released from these
material material
Aust Dent J. 2006 Dec;51(4):328-32Aust Dent J. 2006 Dec;51(4):328-32. .
Properties:Properties:
1. High F concentration produces immediate increase in 1. High F concentration produces immediate increase in
F levels of restorationsF levels of restorations
2. Once re-charging source is removed, re-release 2. Once re-charging source is removed, re-release
immediately beingsimmediately beings
3. High F release occurs for short period of time and 3. High F release occurs for short period of time and
quickly goes back to original levelquickly goes back to original level
(Typically release to normal levels in 1-2 days)(Typically release to normal levels in 1-2 days)
4. Value of F re-charging has never been demonstrated 4. Value of F re-charging has never been demonstrated
clinicallyclinically
ANTIBACTERIAL ACTIVITY OF GICANTIBACTERIAL ACTIVITY OF GIC
Glass ionomer cements have got antibacterial action which has Glass ionomer cements have got antibacterial action which has
been attributed to the release of fluoride. They are effective been attributed to the release of fluoride. They are effective
against S.mutans , S.sobrinus, L.acidophillus and A. viscosus against S.mutans , S.sobrinus, L.acidophillus and A. viscosus
.The best activity is shown by Vitremer (RMGIC .The best activity is shown by Vitremer (RMGIC ).).
(Oper Dent 2005;30-5,636-640 )(Oper Dent 2005;30-5,636-640 )
GICs containing CHX are effective in inhibiting bacteria GICs containing CHX are effective in inhibiting bacteria
associated with caries, and incorporation of 1% CHX diacetate is associated with caries, and incorporation of 1% CHX diacetate is
optimal to give appropriate physical and bonding propertiesoptimal to give appropriate physical and bonding properties
Dental Materials, 2006 Volume 22, Issue 7, Pages 647-652Dental Materials, 2006 Volume 22, Issue 7, Pages 647-652
Do they really prevent recurrent Do they really prevent recurrent
caries?caries?
Despite the release of fluoride ions, in some studies Despite the release of fluoride ions, in some studies
secondary caries has been found to be the main secondary caries has been found to be the main
reason for clinical failure of GIC restorationsreason for clinical failure of GIC restorations
Burke et al., 1999
Hasselrot, 1998
Mjör, 1997
GIC’s are anti-cariogenic in the laboratory when GIC’s are anti-cariogenic in the laboratory when
applied to a chemical model (caries formed only by applied to a chemical model (caries formed only by
acids). In the presence of S.mutans and L. casei, GIC acids). In the presence of S.mutans and L. casei, GIC
materials may not be anti-cariogenicmaterials may not be anti-cariogenic
Sa et al., Oper Dent 2004
BIOCOMPATIBILITY OF GIC
BIOCOMPATIBILITYBIOCOMPATIBILITY
Freshly mixed- very acidic (.9 -1.6)Freshly mixed- very acidic (.9 -1.6)
Ph rises rapidly with in first 20 minPh rises rapidly with in first 20 min
EFFECT ON PULP AND CELLS :EFFECT ON PULP AND CELLS :
Freshly mixedFreshly mixed GICs - cytotoxic GICs - cytotoxic
[Dahl and Tronstad, 1976; Meryon and Coworkers, 1983].[Dahl and Tronstad, 1976; Meryon and Coworkers, 1983].
Although freshly mixed GICs inhibited cellular Although freshly mixed GICs inhibited cellular
proliferation, it was not cytotoxic.proliferation, it was not cytotoxic.
[Kawahara and cowkers, 1979] [Kawahara and cowkers, 1979]
GICs cause greater inflammatory response than Zn-E GICs cause greater inflammatory response than Zn-E
cement but less than ZnPO4 cement and related dental cement but less than ZnPO4 cement and related dental
silicate cements. silicate cements. [Plant et al, 1984] [Plant et al, 1984]
This inflammatory response resolves within 30 days and there This inflammatory response resolves within 30 days and there
is no enhancement of reparative or secondary dentin is no enhancement of reparative or secondary dentin
formation.formation.
The response of gingival tissues towards the cement in class V The response of gingival tissues towards the cement in class V
cavities is minimal. (resistance to plaque)cavities is minimal. (resistance to plaque)
( Garcia( Garcia et al, 1981) et al, 1981)
Possible reasons for BLANDNESS of polyacrylic acid Possible reasons for BLANDNESS of polyacrylic acid
((McLean and Wilson, 1974)McLean and Wilson, 1974)
Poly (acrylic) acid - weak acid Poly (acrylic) acid - weak acid
Ph rises rapidly towards neutralityPh rises rapidly towards neutrality
Diffusion of the polyacid into the dentinal tubules is Diffusion of the polyacid into the dentinal tubules is
unlikely due to its high mol. wt. and chain unlikely due to its high mol. wt. and chain
entanglement.entanglement.
Thinnest layer of dentin is sufficient to bind poly Thinnest layer of dentin is sufficient to bind poly
(acrylic acid) as insoluble salts as it is readily (acrylic acid) as insoluble salts as it is readily
precipitated by Ca2+ in the tubules.precipitated by Ca2+ in the tubules.
Tendency to form complex with protein that limits Tendency to form complex with protein that limits
diffusion of PAAdiffusion of PAA
Citric acid when used as SURFACE CONDITIONER Citric acid when used as SURFACE CONDITIONER
on cut tubules causes on cut tubules causes inflammatory response. inflammatory response.
[Cotton & Siegel, 1978][Cotton & Siegel, 1978]
Linings of ZnOE or Ca(OH)2 cement are required Linings of ZnOE or Ca(OH)2 cement are required
where < 1 mm of sound dentin remains over the pulp.where < 1 mm of sound dentin remains over the pulp.
[McLean and Wilson, 1978][McLean and Wilson, 1978]
FACTORS RESPONSIBLE FOR FACTORS RESPONSIBLE FOR
BIOCOMPATIBILITY OF GIC :BIOCOMPATIBILITY OF GIC :
(1) Minimal exotherm on setting(1) Minimal exotherm on setting
(2) Rapid neutralization on mixing powder and liquid(2) Rapid neutralization on mixing powder and liquid
(3) Slow release of ions which are generally beneficial.(3) Slow release of ions which are generally beneficial.
[J. Biomater Sci Polym Ed. 1991; 2(4); 277-85][J. Biomater Sci Polym Ed. 1991; 2(4); 277-85]
On the contrary:On the contrary:
(1) Resin modified GICs (ComPoglass, Fuji II LC, (1) Resin modified GICs (ComPoglass, Fuji II LC,
Protec Cem) and GC lining cements are more toxic to Protec Cem) and GC lining cements are more toxic to
pulp than conventional GIC.pulp than conventional GIC.
RM GICs should not be applied directly onto pulp RM GICs should not be applied directly onto pulp
cells.cells.
[Oper Dent; July / Aug; 28 (4)]; 2003[Oper Dent; July / Aug; 28 (4)]; 2003
(2) The principal compounds responsible for (2) The principal compounds responsible for
cytotoxicity of RMGIC – unpolymerised resin cytotoxicity of RMGIC – unpolymerised resin
monomer (HEMA) and for MGIC – Cu2+, Ag+.monomer (HEMA) and for MGIC – Cu2+, Ag+.
[Biomed Mater Res; 48; 277-88; 1999][Biomed Mater Res; 48; 277-88; 1999]
ROLE OF GIC IN DIRECT PULP CAPPING:-ROLE OF GIC IN DIRECT PULP CAPPING:-
According to a study,Vitremer has shown pulpal healing According to a study,Vitremer has shown pulpal healing
associated with calcified barrier formation in 60 days.There was associated with calcified barrier formation in 60 days.There was
a large zone of cell rich fibrodentine matrix deposition on the a large zone of cell rich fibrodentine matrix deposition on the
pulp horn related to the exposure site.Tertiary dentine under the pulp horn related to the exposure site.Tertiary dentine under the
fibrodentine matrix was deposited by a layer of elongated pulp fibrodentine matrix was deposited by a layer of elongated pulp
cells.The remaining pulpal tissue exhibited normal histological cells.The remaining pulpal tissue exhibited normal histological
characteristics.characteristics.
(Int Endond Journal;vol 36;pg 831;Dec 2003 )(Int Endond Journal;vol 36;pg 831;Dec 2003 )
ESTHETICSESTHETICS
an esthetic filling material an esthetic filling material
has a degree of translucency has a degree of translucency
because its filler - a glassbecause its filler - a glass
Reported an experimental glass-ionomer cement- Reported an experimental glass-ionomer cement-
ASPA XASPA X
as translucent as tooth material as translucent as tooth material
because of slow hydration reactions, because of slow hydration reactions,
GIC take at least 24 hours to fully mature and to develop full GIC take at least 24 hours to fully mature and to develop full
translucency; translucency;
have long-term aesthetic advantages because, unlike have long-term aesthetic advantages because, unlike
composite resins which stain and lose their colour match in the composite resins which stain and lose their colour match in the
mouth, the colour of GIC remains unaffected by oral fluidmouth, the colour of GIC remains unaffected by oral fluid
Poor translucency
Good tranceluncy
The translucency of dark shades is less than that of the light The translucency of dark shades is less than that of the light
shadeshade
(Crispet aI., 1979;Asmussen, 1983)(Crispet aI., 1979;Asmussen, 1983)
Also, early Contamination of the cement surface with moisture Also, early Contamination of the cement surface with moisture
adversely affects translucencyadversely affects translucency
(Asmussen, 1983)(Asmussen, 1983)
The clinical use of Listerine as an antiseptic solution for a The clinical use of Listerine as an antiseptic solution for a
short period of time may interfere less intensively with the short period of time may interfere less intensively with the
translucence of the restorative material Chelon Fil. translucence of the restorative material Chelon Fil.
Braz Dent J (2001) 12(2): 91-94Braz Dent J (2001) 12(2): 91-94
Stains penetrate into the glass-ionomer cement to a Stains penetrate into the glass-ionomer cement to a
much lesser extent than is the case with composite much lesser extent than is the case with composite
resinresin
(Lingard et aI., 1978(Lingard et aI., 1978))
However, resistance to stain However, resistance to stain
largely dependent on obtaining a good surface finish.largely dependent on obtaining a good surface finish.
resin modified glass ionomer cements demonstrate resin modified glass ionomer cements demonstrate
excellent colour match and translucency soon after excellent colour match and translucency soon after
light curing.light curing.
Dissolution and erosionDissolution and erosion
Wilson and coworkers (1986)Wilson and coworkers (1986)
found that the acid-erosion of the various types of water-based found that the acid-erosion of the various types of water-based
dental cements increased in this order:dental cements increased in this order:
glass ionomer < silicate < zinc phosphateglass ionomer < silicate < zinc phosphate
< polycarboxylate< polycarboxylate
Once the glass-ionomer - fully matured, Once the glass-ionomer - fully matured,
only nonmatrix elements are leached, (sodium, fluoride, and only nonmatrix elements are leached, (sodium, fluoride, and
silica). silica).
not matrix-forming speciesnot matrix-forming species
DURABILTYDURABILTY
the most important factor - the care devoted to it during the first the most important factor - the care devoted to it during the first
few minutes of its lifefew minutes of its life
Durability is affected by a number of factors:Durability is affected by a number of factors:
inadequate preparation of the cement inadequate preparation of the cement
inadequate protection of the restoration,inadequate protection of the restoration,
the variable conditions of the mouth.the variable conditions of the mouth.
Cervical erosion lesions-Class V Cervical erosion lesions-Class V
Tyas and Beech (1985) compared all the properties of glass-Tyas and Beech (1985) compared all the properties of glass-
ionomer cement with those of alternative materials and ionomer cement with those of alternative materials and
concluded that it remains the material of choice for Class V concluded that it remains the material of choice for Class V
restorations.restorations.
Thermal expansion and diffusivity
• a linear coefficient of thermal expansion
similar to that of tooth structure.
• thermal diffusivity is also close to that of
tooth structure
IMPROVED TRADITIONAL GLASS IONOMERS
HIGHLY VISCOUS GLASS IONOMER/ CONDENSABLE GIC
These were developed early in 1990
It is designed as an alternative to amalgam
Particularly used for ART technique
Other uses:
•Intermediate restoration
•Replacing amalgams
•For core buildup procedure
LOW VISCOUS GLASS IONOMER CEMENT
Have been developed as liners, fissure protection material
Sealing material for hypersensitive cervical areas
Endodontic materials
Low P:L ratio, material decreases dissolution from occlusal surfaces
and causes increased fluoride release which strengthens the tooth
structure, suitable for fissure protection
INTRODUCED BY SIMMONS IN 1983 .
11
Addition of spherical silver alloy powder to type II
Restorative glass cement = Miracle mix
Improved properties
Compressive strength
Tensile strength
Creep resistance
It showed less microleakage than the three other GIC
Increased flexural strength
Increased fluoride release
But:
Brittle
Low fracture toughness
Metal modified
GIC
150 C.S
6.7 T.S
39 KHN
Mild (PR)
Yes (AC)
0.1
THIS WAS INTRODUCED BY MCLEAN & GASSER
IN 1985 .
High wear resistance
Core build up .
Restoration of primary teeth.
Restoration of approximal lesions [ tunnel
preparation ] .
Treatment of root caries
Repair of defective margins in restorations.
Retrograde root fillings.
IN 1988 THE FIRST LIGHT CURABALE GIC WAS INTRODUCED IN 1988 THE FIRST LIGHT CURABALE GIC WAS INTRODUCED
COMPOSITIONCOMPOSITION
Powder componentPowder component contains ion – leachable contains ion – leachable
fluoroaluminosilicate glass particles & initiators for light curing fluoroaluminosilicate glass particles & initiators for light curing
& / or chemical curing.& / or chemical curing.
Initiator / ActivatorInitiator / Activator
Liquid componentLiquid component contains water & polyacrylic acid modified contains water & polyacrylic acid modified
with methacrylate & hydroxy ethyl methacrylate [ HEMA ] with methacrylate & hydroxy ethyl methacrylate [ HEMA ]
monomers for polymerization.monomers for polymerization.
Chemical
polymerization
Initiator : Hydrogen peroxide
Activator : Ascorbic acid
Co activator: Cupric sulphate..
light activated
Initiator: Camphoroquinone
Activator: Sodium p toluene sulphinate.
Photo activator: 4-NN dimethyl amino
benzonate.
Two distinct types of curing / setting reactions occur Two distinct types of curing / setting reactions occur
in this type of glass ionomer. in this type of glass ionomer.
Acid - Base reaction.Acid - Base reaction.
Free radical methacrylate cure.Free radical methacrylate cure.
The relationship between these 2 reactions may take The relationship between these 2 reactions may take
one of two forms.one of two forms.
SETTING REACTION ;
Formation of 2 separate matrix
An ionomer salt hydrogel &
Poly HEMA matrix
Multiple cross linking – Methacrylate
group replaces small fractions
Carboxylate groups of PAA
CLASSIFICATION ;
I ) DUAL CURE ;
II ) TRI - CURE ;
1. Visible light free radical methacrylate Visible light free radical methacrylate
polymerization , polymerization ,
2.2. Conventional acid base reaction Conventional acid base reaction
3.3. Chemical cure of free radical methacrylate Chemical cure of free radical methacrylate
polymerisation of the resin eg ; Vitremerpolymerisation of the resin eg ; Vitremer
1. Visible light cure free – radical polymerization Visible light cure free – radical polymerization
2.2. Glass ionomer setting mechanism ( acid – base Glass ionomer setting mechanism ( acid – base
reaction) e.g Geristorereaction) e.g Geristore . .
CHARACTERISTICS OF HYBRID IONOMER CEMENTS.
Translucency is improved because of the inclusion of the
monomer.
Tensile strength are higher than conventional GIC.
Bond strength to tooth structure is higher than conventional
GIC.
Polymerization results in greater degree of shrinkage upon
setting, increases MICROLEAKAGE compared to conventional
GIC
Decreased water sensitivity
Long working time controlled by photo curing.
Improved setting characteristics.
Early strength
Can be finished & polished immediately after
set .
Repairs are carried out, as the bond between old
& new material is strong.
Increased adhesion to composite.
Restoration of deciduous teeth
Minimal cavity preparation / tunnel
preparation
Liner
Fissure sealant
Adhesive for ortho brackets
Core – build up.
Repair of defective margins in restorations.
Restoration of Class III , Class V carious
lesions.
This material is defined by Mc clean &
Nicholson as “Materials that may
contain either or both of the essential
components of GIC but at levels
insufficient to promote the acid base
curing reaction in the dark ’’.
Products:Products: I Gen: Dyract
Dyract AP
II Gen: Compoglass
F 2000
Hytac Aplicap
Compoglass F
A . RESIN MATRIX .
1)1)UDMAUDMA
2)2)TCB RESIN [ TETRA CARBOXYLIC ACID + HEMA AS SIDE CHAIN ].TCB RESIN [ TETRA CARBOXYLIC ACID + HEMA AS SIDE CHAIN ].
3)3)FILLERS - STRONTIUM FLUORO SILICATE GLASS & DEHYDRATED FILLERS - STRONTIUM FLUORO SILICATE GLASS & DEHYDRATED
PAA ACID PAA ACID
4)4)STRONTIUM FLUORIDE..STRONTIUM FLUORIDE..
B . PRIMER / ADHESIVE SYSTEM.
1)1)PENTA - This is an acidic monomer made up of phosphoric PENTA - This is an acidic monomer made up of phosphoric
acid acid
2)2)TEGDMA - Provides elasticity to the cured primer / adhesive.TEGDMA - Provides elasticity to the cured primer / adhesive.
3)3) ACETONE - Acts as a solvent which carries the resin & helps ACETONE - Acts as a solvent which carries the resin & helps
to wet the tooth surface & assist the penetration of resin in to wet the tooth surface & assist the penetration of resin in
the dentin surface.the dentin surface.
Advantages
Sup working characteristics
Ease of use
Esthetics
F- release( but less than rmgic)
C.T $ T.S
Restoration of deciduous teeth
Minimal cavity preparation / tunnel
preparation
Lining of all types of cavities where a
biological seal & cariostatic action is required.
Core – build up.
Repair of defective margins in restorations.
Restoration of Class III , Class V carious
lesions.
Provisional restoration where future veneer
crowns are contemplated.
Conventiona
l Glass
Ionomer
Resin-
Modified
Glass
Ionomer
Compomers Fluoride
Releasing
Resin
Composite
Resin
Typical ProductsKetac-fil
Fuji II, Fuji
IX, *Ketac-
silver,
Miracle
Mix
Fuji II LC,
Photac-fil
Quik,
Vitremer
Dyract AP,
Elan,
F2000,
Compogla
ss F
GeriStore,
Variglass,
Resinomer,
Hytac
Herculite XRV,
Prisma
TPH,
Heliomolar,
Tetric
Ceram,
Solitaire,
SureFil
Fluoride ReleaseHigh
(*Ketac-
silver
medium)
High Medium Low Lowest
Fluoride
Recharge
High High Some Very Low None
Thermal
Expansion
Lowest Medium Highest
Translucency Lowest Highest
Tensile Strength
& Fracture
Toughness
Lowest Highest
SMART MATERIALSSMART MATERIALS
Materials that restore and prevent dental cariesMaterials that restore and prevent dental caries
The prophylactic role of F- in dental caries was The prophylactic role of F- in dental caries was
reported by ERHARBT as early as 1874reported by ERHARBT as early as 1874
Smart materials apart from releasing F- also act as a Smart materials apart from releasing F- also act as a
reservoir of F-. They exist in a dynamic equilibrium reservoir of F-. They exist in a dynamic equilibrium
with the surrounding controlling the leach of F- by with the surrounding controlling the leach of F- by
their ability to recharge.their ability to recharge.
GIOMERSGIOMERS
New class of materialsNew class of materials
the hybridisation of Glass-lonomer and the hybridisation of Glass-lonomer and
Composite ResinComposite Resin
to develop a new family of fluoride releasing to develop a new family of fluoride releasing
direct aesthetic restoratives and adhesives direct aesthetic restoratives and adhesives
called "GIOMER" characterized by Pre-called "GIOMER" characterized by Pre-
Reacted Glass-Ionomer (PRG) technology.Reacted Glass-Ionomer (PRG) technology.
Pre-Reacted Glass-Ionomer (PGR) technologyPre-Reacted Glass-Ionomer (PGR) technology
Resin-based; contain pre-reacted glass ionomer Resin-based; contain pre-reacted glass ionomer
particles (PRG). particles (PRG).
Fluoroaluminosilicate glass is pre-reacted with Fluoroaluminosilicate glass is pre-reacted with
polyacrylic acid prior to being incorporated into polyacrylic acid prior to being incorporated into
resin.resin.
This technology can be classified into two This technology can be classified into two
categoriescategories
F-PRG Technology - Used fully reacted glass filler.F-PRG Technology - Used fully reacted glass filler.
S-PRG Technology - Used surface reacted glass filler. S-PRG Technology - Used surface reacted glass filler.
PROPERTIES :PROPERTIES :
* * F- releaseF- release
* F- recharge* F- recharge
* Excellent esthetics* Excellent esthetics
* Easy polishability* Easy polishability
* Biocompatibility* Biocompatibility
*Light activated and require use of BONDING AGENT *Light activated and require use of BONDING AGENT
to adhere to tooth structureto adhere to tooth structure
STUDIES :STUDIES :
(1) Release F- but do not have an initial “burst” type of (1) Release F- but do not have an initial “burst” type of
release like GI and long term (28 days) release is release like GI and long term (28 days) release is
decrease decrease
[Oper Dent : 2002; 27 ; 259-65][Oper Dent : 2002; 27 ; 259-65]
(2) When polished with sof-lex disks, they have a (2) When polished with sof-lex disks, they have a
smoother surface than a GI. Comparable to compomer smoother surface than a GI. Comparable to compomer
and resin composite.and resin composite.
[Oper Dent; 2002; 27 ; 161-66][Oper Dent; 2002; 27 ; 161-66]
INDICATIONS :INDICATIONS :
Root cariesRoot caries
Non carious cervical Non carious cervical
lesionslesions
Class V cervical lesionsClass V cervical lesions
Primary tooth cariesPrimary tooth caries
CONTRAINDICATIONS: CONTRAINDICATIONS:
Class I lesions (decrease wear resistance)Class I lesions (decrease wear resistance)
Shofu Reactmer (GIOMER)
-- Restorations
AMALGOMERAMALGOMER
These are restoratives with :These are restoratives with :
(1) GIC with the strength of (1) GIC with the strength of
amalgam amalgam
(2) Ceramic reinforcement(2) Ceramic reinforcement
Available as ‘anterior’ as Available as ‘anterior’ as
well as ‘posterior’ restorative well as ‘posterior’ restorative
materials.materials.
The Anterior ChoiceThe Anterior Choice
Amalgomer Technology - latest innovation in restorative Amalgomer Technology - latest innovation in restorative
dentistry. dentistry.
For the first time the strength of a classic amalgam For the first time the strength of a classic amalgam
restorative has been combined with the aesthetics and the restorative has been combined with the aesthetics and the
many other advantages of Glass Ionomers. many other advantages of Glass Ionomers.
FEATURES:- FEATURES:-
Designed to match the strength and durability of amalgam Designed to match the strength and durability of amalgam
Sustained high level of Fluoride release Sustained high level of Fluoride release
Superb aesthetics, Industry standard shading Superb aesthetics, Industry standard shading
Minimal cavity preparation Minimal cavity preparation
Natural adhesion to tooth structure, Good biocompatibility Natural adhesion to tooth structure, Good biocompatibility
Hard, snappy chemical set with good working time Hard, snappy chemical set with good working time
Water mix and Powder/Liquid versions available Water mix and Powder/Liquid versions available
No shrinkage, corrosion, expansion or thermal conductivity No shrinkage, corrosion, expansion or thermal conductivity
problems associated with other filling materials problems associated with other filling materials
The Posterior ChoiceThe Posterior Choice
AMALGOMER CR - Ceramic Reinforced Posterior GIC. AMALGOMER CR - Ceramic Reinforced Posterior GIC.
stronger compressive, flexural and tensile strengths. stronger compressive, flexural and tensile strengths.
Features :- Features :-
Exceptional wear characteristics Exceptional wear characteristics
Superior radiopacity Superior radiopacity
Excellent for core build ups Excellent for core build ups
Excellent for Posterior Restorations Excellent for Posterior Restorations
Available in White and a Universal tooth shade Available in White and a Universal tooth shade
Designed to match the strength and durability of amalgam Designed to match the strength and durability of amalgam
Sustained high level of Fluoride release Sustained high level of Fluoride release
Good biocompatibility, natural adhesion to tooth structure Good biocompatibility, natural adhesion to tooth structure
Water mix and Powder/Liquid versions available Water mix and Powder/Liquid versions available
new bioactive material: HAIonomer cements new bioactive material: HAIonomer cements
(hydroxyapatite-ionomer )(hydroxyapatite-ionomer )
lack of exotherm during setting, absence of monomer lack of exotherm during setting, absence of monomer
and improved release of incorporated therapeutic and improved release of incorporated therapeutic
agents agents
Potential uses of Potential uses of
bone cements bone cements
performed implants for hard tissue replacement in the performed implants for hard tissue replacement in the
field of otological, oral-maxillofacial and orthopedic field of otological, oral-maxillofacial and orthopedic
surgery surgery
Biomaterials. 2002 Feb;23(3):955-62 Biomaterials. 2002 Feb;23(3):955-62
What is the position of GIC???What is the position of GIC???
Pulp Compatibility:Pulp Compatibility: Bioactive & OsteoinductiveBioactive & Osteoinductive - Dent Mater 2005 - Dent Mater 2005
Secondary CariesSecondary Caries - DCNA 2002 - DCNA 2002
GICs < Composites < AmalgamGICs < Composites < Amalgam
13% 15% 28% 13% 15% 28%
Fluoride Release & RechargeFluoride Release & Recharge - DCNA 2001 - DCNA 2001
GICs > Compomers > CompositesGICs > Compomers > Composites
Volumetric contractionVolumetric contraction - Aust Dent Journal 2007 - Aust Dent Journal 2007
GICs < Composites < Compomers GICs < Composites < Compomers
Wear Wear - Am J Dent 1997 - Am J Dent 1997
Compomers > GICs > CompositesCompomers > GICs > Composites
Tensile StrengthTensile Strength - J Adhes Dent 2002 - J Adhes Dent 2002
GICs < Compomers < CompositesGICs < Compomers < Composites
TO A DENTIST
Esthetic is what I am gentle, friendly in
any situation these two I am
Handle me with care as I can be the next
best thing to what a tooth can ever have
Pamper me, protect me in my childhood
years.
I shall be grateful and benefit you till
death do us apart.
Yours sincerely
GIC
REFERENCESREFERENCES
GLASS IONOMER CEMENT – Wilson / McLean.GLASS IONOMER CEMENT – Wilson / McLean.
AN ATLAS OF GLASS IONOMER CEMENT – A AN ATLAS OF GLASS IONOMER CEMENT – A
CLINICIAN’S GUIDE – G.J. MOUNTCLINICIAN’S GUIDE – G.J. MOUNT
ADVANCES IN GLASS IONOMER CEMENT- ADVANCES IN GLASS IONOMER CEMENT-
DAVIDSON AND MJORDAVIDSON AND MJOR
PHILLIP’S SCIENCE OF DENTAL MATERIALSPHILLIP’S SCIENCE OF DENTAL MATERIALS
STURDEVENT’S ART & SCIENCE OF OPERATIVE STURDEVENT’S ART & SCIENCE OF OPERATIVE
DENTISTRY DENTISTRY
RESTORATIVE MATERIALS – CRAIGRESTORATIVE MATERIALS – CRAIG
ENDODONTICS – INGLEENDODONTICS – INGLE
Mount G.J, Hume W.R : Preservation and restoration Mount G.J, Hume W.R : Preservation and restoration
of tooth structure, Mosby, 1998.of tooth structure, Mosby, 1998.
An update on glass ionomerc ements, Dent Update, An update on glass ionomerc ements, Dent Update,
Sep 1995Sep 1995
Dent Update, Nov. 1990.Dent Update, Nov. 1990.
Aus. Dent J, Vol.44(1),1999.Aus. Dent J, Vol.44(1),1999.
Aus Dent J, Vol. 49 (3),2004.Aus Dent J, Vol. 49 (3),2004.
Dent Update Dec 1995Dent Update Dec 1995
Dent UpdateDec 1995.8.Dent UpdateDec 1995.8.
Dent Update Jan/Feb,1996.9. Dent Update Jan/Feb,1996.9.