GLASS IONOMERSGLASS IONOMERSin Restorative Dentistryin Restorative Dentistry

The many faces of glass ionomers

• GI -- what are they ?• GI categories ?• GI setting reactions ?• GI release of F and recharging ?• GI applications ?

19701970 19801980 2000200019901990

Dental AmalgamDental Amalgam

Dental CompositeDental Composite

Glass IonomerGlass Ionomer

First GIC in 1972First GIC in 1972Dentsply A.S.P.A.Dentsply A.S.P.A.

A.S. = A.S. = AAluminoluminossilicate glassilicate glassP.A. = P.A. = PPolyacrylic olyacrylic aacid in watercid in water

DEVELOPMENTDEVELOPMENTTimeline for “direct restorative materials” usageTimeline for “direct restorative materials” usage

Glass IonomerGlass Ionomer:: “glass” refers to the glassy ceramic particles and the “glass” refers to the glassy ceramic particles and the glassy matrix (non-crystalline) of the set material, while “ionomer” glassy matrix (non-crystalline) of the set material, while “ionomer” refers to ion-crosslinked polymer.refers to ion-crosslinked polymer.

Polyalkenoic or PolyalkenoatePolyalkenoic or Polyalkenoate: : refers to polymer chain which refers to polymer chain which incorporates alkenoic monomers such as acrylic acid, tartaric acid, incorporates alkenoic monomers such as acrylic acid, tartaric acid, maleic acid, etc.maleic acid, etc.

F-ReleaseF-Release:: refers to release of fluoride ions but there is no implication refers to release of fluoride ions but there is no implication as to the source of the ions -- and there are many possibilities. The as to the source of the ions -- and there are many possibilities. The confusion for current systems is, if “F” does not come from the confusion for current systems is, if “F” does not come from the traditional GI matrix, then some people say that the system is not a traditional GI matrix, then some people say that the system is not a “true” GI (but the point is irrelevant).“true” GI (but the point is irrelevant).

Multiple-CureMultiple-Cure:: refers to multiple curing mechanisms possible with refers to multiple curing mechanisms possible with resin-modified systems -- the terminology was first introduced in 1992 resin-modified systems -- the terminology was first introduced in 1992 by 3M for their Vitremer product because it underwent the (1) by 3M for their Vitremer product because it underwent the (1) traditional GI chemical setting reactions, (2) a self-cured traditional GI chemical setting reactions, (2) a self-cured polymerization reaction, and a (3) light-cured polymerization reaction.polymerization reaction, and a (3) light-cured polymerization reaction.

TERMINOLOGYTERMINOLOGYDon’t be confused by some of the strange language.Don’t be confused by some of the strange language.

Si, Na,F, Ca,

Al

H2O,H3PO4,Al, Zn

+Ca+2Al+3F-

Si+4

H+

Glass particleEtched periphery

Ca, Al, Na, ZnPhosphates andFluorides

REACTANTS PRODUCTS

Silicate CementSilicate Cement

ZnO H2O PAA

ZnO + COOH

HOOC

COOHHOOC -OOC

COO-

-OOC

COO-Zn++

Zn++COO-

-OOC

COO--OOC

ResidualZnO

Zinc polyacrylate gel

Polycarboxylate CementPolycarboxylate Cement

GLASS IONOMERSGLASS IONOMERSHYBRID = HYBRID = SC [Powder]SC [Powder] and and PCC [Liquid]PCC [Liquid] = A.S.P.A. = A.S.P.A.

SiO2,Al2O3,Na, Ca, F

PAAin

H2O

SiO2,Al2O3,Na, Ca, F

Residual Glass Particle

POLYACRYLATE HYDROGEL(initially Ca polyacrylate geland later Al polyacrylate gel)

Si+4, Al+3, Ca+2, Na+, F- Ions

SiO2,Al2O3,Na, Ca, F

Si+4

Al+3

Na+

Ca+2 F-

PAA

H2O

GLASS IONOMERSGLASS IONOMERSHYBRID = HYBRID = SC [Powder]SC [Powder] and and PCC [Liquid]PCC [Liquid] = A.S.P.A. = A.S.P.A.

COOCOO¯̄

COOCOO¯̄

¯OOC¯OOC

COOCOO¯̄

COOCOO¯̄

COOCOO¯̄

COOCOO¯̄

¯OOC¯OOC

¯OOC¯OOC

¯OOC¯OOC

¯OOC¯OOC

Al+3Al+3

--O-Si+4(OH)--O-Si+4(OH)22

Ca++Ca++

Ca+Ca+

Ca+Ca+¯OOC¯OOC

¯OOC¯OOC

COOCOO¯̄¯OOC¯OOC

COOCOO¯̄

F-Al-SiOF-Al-SiO22

CaFCaF22

H-O-HH-O-H

H-O-HH-O-H

H-O-HH-O-H

H-O-HH-O-H

H-O-HH-O-H

CaCa+2+2 AlAl+3+3

SiSi+4+4FF--

GI SETTING REACTIONSGI SETTING REACTIONS

UniversalUniversalCEMENTSCEMENTS

GIGI

COMPOSITECOMPOSITE

HYDROGELHYDROGEL

Hydrophobic POLYMERHydrophobic POLYMER

RM-GIRM-GI GI and VLC Hydrophilic monomer and polymer

CEMENTSCEMENTS

MM-GIMM-GI GI and Metallic fillers Cermet fillers

CORESCORES

COMPOMERCOMPOMER VLC Composite and F source

FILLING MATERIALSFILLING MATERIALS

RR-GIRR-GI

GI and Resin-Fillers

A.R.T. andA.R.T. andTEMPORARIESTEMPORARIES

GIOMERGIOMER VLC Composite and Pre-reacted GIC powder

FILLING MATERIALSFILLING MATERIALS

CEMENTSCEMENTS

FILLING MATERIALSFILLING MATERIALS

FLUORO-ALUMINO-SILICATEFLUORO-ALUMINO-SILICATE

PARTICLEPARTICLECEMENTCEMENTMATRIXMATRIX

F-1, Ca+2, Al+3, Si+4

Initialdissolution

for startingreaction

rapid earlyF release

from matrixSlow long term

F releaseby diffusionfrom particle

FLUORIDE RELEASEFLUORIDE RELEASEFluoride comes from matrix and particles at different rates.Fluoride comes from matrix and particles at different rates.

EFFECTIVE LEVELSEFFECTIVE LEVELS

2020

1010

1515

55

1414 2121 28287700

TIME (Days)TIME (Days)

FL

UO

RID

E R

EL

EA

SE

(p

pm

)F

LU

OR

IDE

RE

LE

AS

E (

pp

m)

Fluoride Toothpaste,Fluoride Toothpaste,Topical Fluoride,Topical Fluoride,Fluoride MouthrinseFluoride Mouthrinse

PARTICLESPARTICLES

MA

TR

IXM

AT

RIX

Mjor IA.Mjor IA. Glass ionomer cement restorations and secondary caries: a Glass ionomer cement restorations and secondary caries: a preliminary report.preliminary report. Quintessence Int Quintessence Int 1996;1996;27(3):171-174.

Glass IonomerGlass Ionomer

CompositeComposite

AmalgamAmalgam

Replacement rate (%) for secondary cariesReplacement rate (%) for secondary caries

0 20 40 60 80 100

CARIOSTATIC EFFECTSCARIOSTATIC EFFECTSGI is not more effective than composite or amalgam.GI is not more effective than composite or amalgam.

1.1. CementCement2.2. Liner / BaseLiner / Base3.3. RestorationRestoration4.4. Core / FoundationCore / Foundation5.5. (Tunnel Restoration)(Tunnel Restoration)6.6. (Sandwich Restoration)(Sandwich Restoration)7.7. Retrograde Filling MaterialRetrograde Filling Material8.8. P/F SealantP/F Sealant9.9. Root Caries Cervical RestorationRoot Caries Cervical Restoration10.10. Temporary, or ART RestorationTemporary, or ART Restoration

Technical modifications:> P/L Precapsulated> Addition of etching and then BA> Addition of different reinforcing fillers> Finer and finer particle sizes

General Properties:> Strength> Adhesion> Biocompatibility> Fluoride release

APPLICATIONSAPPLICATIONSGI have been tried for about every conceivable application.GI have been tried for about every conceivable application.

COMMERCIAL PRODUCTSCOMMERCIAL PRODUCTS

Hytac

Vitremer

Ketac-Cem Dyract Flow

Fuji Miracle Mix

SOME PRODUCTSSOME PRODUCTS

Fuji IX

Now being used as permanent restoration in pedodontics.

Developed as temporary restorations for 3rd world countries.First tested in African countries.Now used widely in Asian countries.

Current technique = P/L or precapsulated mixture.Original technique = scoop, finger mix, finger insertion.

A.R.T. RESTORATIONSA.R.T. RESTORATIONSART = Atraumatic Restorative TechniqueART = Atraumatic Restorative Technique

““WHO” Global A.R.T. ProjectWHO” Global A.R.T. ProjectAtraumatic Restorative Treatment (ART) = prevention and treatment of dental cariesbased on excavating and removing caries using hand instruments only and restoring glass ionomer.

Fuji IX GPFuji IX GP

Minimal equipment and instrumentation

TEMPORARY RESTORATIONSTEMPORARY RESTORATIONSFuji IX Dominates the LandscapeFuji IX Dominates the Landscape