Fluoride-Releasing Materials IFluoride-Releasing Materials IGlass Inomer & Resin Modified Glass InomerGlass Inomer & Resin Modified Glass Inomer

Dr.Ghada Maghaireh Dr.Ghada Maghaireh BDS, MS, ABODBDS, MS, ABOD

Lecture OutlineLecture Outline

What is glass inomer?What is glass inomer?

Classification of glass inomer.Classification of glass inomer.

Advantages & disadvantages of using glass Advantages & disadvantages of using glass inomer.inomer.

Development & use of glass inomer.Development & use of glass inomer.

The fluoride releasing material continuum.The fluoride releasing material continuum.

Dental CementsDental Cements

Liquid

Zinc OxideZinc Oxide Aluminosilicate Aluminosilicate

GlassGlass

Phosphoric Phosphoric

acidacid

Zinc Phosphate Zinc Phosphate cementcement

Silicate cementSilicate cement

Polyacrylic Polyacrylic acidacid

Polycarboxylate Polycarboxylate

cementcement

Glass Inomer cementGlass Inomer cement

Powder

Glass inomer cement (GIC) - CompositionGlass inomer cement (GIC) - Composition

““Glass” Glass” BasicBasic ion-leachable ion-leachable calcium fluoro-calcium fluoro-

alumino-silicate glass powderalumino-silicate glass powder

““Ionomer”Ionomer” Acrylic acidAcrylic acid Maleic acidMaleic acid Itaconic acidItaconic acid Butene Butene

dicarboxylic aciddicarboxylic acid Vinyl phosphonic Vinyl phosphonic

acidacid

Glass inomer cement – Setting ReactionGlass inomer cement – Setting Reaction

Acid Base ReactionAcid Base Reaction

Liquid acid attacks glass.Liquid acid attacks glass.

Glass decomposition, metal ion release (Calcium, Glass decomposition, metal ion release (Calcium, Aluminum, Fluoride).Aluminum, Fluoride).

Migration of metal ions into liquid.Migration of metal ions into liquid.

Gelation of matrix by metal ions.Gelation of matrix by metal ions.

Post-set hardening by continued binding of metal ions.Post-set hardening by continued binding of metal ions.

Slow maturation (cross-linking, hydration, silica matrix).Slow maturation (cross-linking, hydration, silica matrix).

Simplified Diagram of Setting ReactionSimplified Diagram of Setting Reaction

Polyacrylic AcidPolyacrylic Acid

H+ Anions

Aluminosilicateglass

Matrix(Polycarboxylate salts)

Ca2+,Al3+,Na+, F-

Silica gel

core

Transport media for fluoride. Transport media for fluoride.

Stabilizes the set matrix (25 - 50% water).Stabilizes the set matrix (25 - 50% water).

Solvation of ionomers/polymers and metal Solvation of ionomers/polymers and metal ions.ions.

Role of WaterRole of Water

Glass Inomer Cement loses and gains water Glass Inomer Cement loses and gains water easily:easily:

EarlyEarly moisture contaminationmoisture contamination leads to leads to increased increased solubilitysolubility and and poor esthetics,poor esthetics,(protect for first 7 minutes).(protect for first 7 minutes).

LaterLater desiccationdesiccation causes causes shrinkageshrinkage and and crazingcrazing, , (maybe even months later).(maybe even months later).

How fluoride works:How fluoride works:

Inhibits demineralization.Inhibits demineralization.

Enhances remineralization.Enhances remineralization.

Improves enamel crystal structure (fluorapatite).Improves enamel crystal structure (fluorapatite).

More readily taken up in demineralized enamel.More readily taken up in demineralized enamel.

Inhibits the process by which cariogenic bacteria Inhibits the process by which cariogenic bacteria metabolize carbohydrates (inhibits acid production).metabolize carbohydrates (inhibits acid production).

Interferes with ionic bonding during pellicle and plaque Interferes with ionic bonding during pellicle and plaque formation on tooth surface.formation on tooth surface.

FluorideFluoride

““halo” effect around restoration ~ 3 mm. halo” effect around restoration ~ 3 mm.

Level around restoration ~ 10 ppm.Level around restoration ~ 10 ppm.

Level in saliva of average patient ~ 0.08 ppm.Level in saliva of average patient ~ 0.08 ppm.

Fluorine release from GIC does not lead to Fluorine release from GIC does not lead to restoration breakdown.restoration breakdown.

GIC - Fluoride ReleaseGIC - Fluoride Release

Fluoride Release RatesFluoride Release Rates

Show burst for 1 Show burst for 1 to 2 days followed to 2 days followed by a rapid decline by a rapid decline to steady-state.to steady-state.

Recharging.Recharging.

ADA ClassificationADA Classification

Type I:Type I: luting agents luting agents (Ketac-Cem, Fuji I)(Ketac-Cem, Fuji I)

Type II:Type II: restorative materialrestorative material

a = tooth-colored (Ketac-Fil, a = tooth-colored (Ketac-Fil, Fuji IX)Fuji IX)

b = reinforced (Ketac-Silver, “Miracle Mix”)b = reinforced (Ketac-Silver, “Miracle Mix”)

Type III:Type III:

fast-set liners and bases (Ketac-Bond)fast-set liners and bases (Ketac-Bond)

Classification

ClassificationUsage ClassificationUsage Classification

Restorative materialRestorative material

Traditional (Traditional (Fuji II, Ketac-Fil)Fuji II, Ketac-Fil) Highly viscous (Highly viscous (Fuji IXFuji IX, Ketac-Molar), Ketac-Molar) Metal reinforced (Metal reinforced (Miracle Mix, Ketac-Silver)Miracle Mix, Ketac-Silver)

Base/linerBase/liner

GC lining cement, Ketac-BondGC lining cement, Ketac-Bond Root surface sealingRoot surface sealing

Cervical CementCervical Cement Root canal sealingRoot canal sealing

Ketac-EndoKetac-Endo

Strengths:Strengths:

Ionic exchange leads to Ionic exchange leads to adhesionadhesion to to

tooth structure (chemical bond).tooth structure (chemical bond).

FluorideFluoride release and “rechargeable”. release and “rechargeable”.

GIC – Physical PropertiesGIC – Physical Properties

GIC – Physical PropertiesGIC – Physical Properties

WeaknessesWeaknesses Moisture sensitivity.Moisture sensitivity. Lack of command cure, i.e. doesn’t cure Lack of command cure, i.e. doesn’t cure

with light.with light. Esthetics.Esthetics. Not recommended for stress-bearing areas.Not recommended for stress-bearing areas. Difficult handling.Difficult handling.

High caries risk patientHigh caries risk patient

Atrumatic Restorative Treatment (ART)Atrumatic Restorative Treatment (ART)

Pediatric dentistryPediatric dentistry

Class V lesionsClass V lesions

Liners & bases & sandwich techniqueLiners & bases & sandwich technique

Luting agentsLuting agents

Core buildups ??? Maybe if > 2/3 of tooth structure remainsCore buildups ??? Maybe if > 2/3 of tooth structure remains

Orthopedics (bone substitute material)Orthopedics (bone substitute material)

GIC – IndicationsGIC – Indications

Steps of Clinical Use of Glass InomerSteps of Clinical Use of Glass Inomer

1. Mechanical retention in preparation 1. Mechanical retention in preparation advised (no bevels).advised (no bevels).

Steps of Clinical Use of Glass InomerSteps of Clinical Use of Glass Inomer

2. Dentin conditioning (10 2. Dentin conditioning (10 % polyacrylic acid for % polyacrylic acid for 10-20 seconds).10-20 seconds).

3. Inject into preparation. 3. Inject into preparation. Overfill the preparation.Overfill the preparation.

Steps of Clinical Use of Glass InomerSteps of Clinical Use of Glass Inomer

4. Trim excess with finishing bur (wet, with very 4. Trim excess with finishing bur (wet, with very light pressure as the cement material cuts light pressure as the cement material cuts easily!) and polish (if necessary). Be cautious easily!) and polish (if necessary). Be cautious not to over-reduce, the material is “softer” than not to over-reduce, the material is “softer” than composite resin.composite resin.

5. Dry the surface and paint on a thin layer of light-5. Dry the surface and paint on a thin layer of light-cured unfilled resin (smoothes the surface and cured unfilled resin (smoothes the surface and prevents desiccation but lowers fluoride release. prevents desiccation but lowers fluoride release. (optional)(optional)

ReferencesReferences

Chapter 13 Fundamentals of Chapter 13 Fundamentals of Operative Dentistry.Operative Dentistry.