Glass Ionomer in Contemporary

Restorative Dentistry

By Rooj Rojasawasthien. DDS, MSc.

16 August 2010

Direct Tooth Colored Material

• Resin composite• Compomer (Polyacid

Modified Resin)• Glass Ionomer• Resin Modified Glass

Ionomer

Direct Tooth Colored Material

GICGlass Ionomer

Cements

RMGIResin-ModifiedGlass Ionomers

PAMRPolyacid-ModifiedResin (compomer)

IMCRIonomer-Modified

Composite Resins

(fluoride in resin)

CRComposite Resins(glass-containing

Hydrophobic resins)

Glass Ionomer• Silicate cements ---> Glass

ionomer (Wilson and Kent, 1972)

• Powder + Liquid• Fluoroaluminosilicate glass

+ Polyalkenoic acid• Acid – Base reaction

Mixing - Shiny, Glossy

Phase I (Ion-leaching phase)Polyacid extracts ions from glass

powder

Setting (3-6 min) - Rigid, Opaque

Phase II (Hydrogel phase)Ion cause formation of polyacid

matrix

Maturation (24 hrs – 1 yrs) More tooth-like color

Phase III (Polysalt gel phase)Silica gel forms and attaches

powder to matrix

Fully set Glass Ionomer

Advantages• Less shrinkage than

polymerizing resin• No free monomers, Non-

irritating to pulp• Coefficient of thermal expansion similar to dentin

• High compressive strength

Advantages

• Adhere chemically to enamel and dentin (hydrophilic)

Advantage• Fluoride release and

recharge (reservoir effect)

Delbem et al., 2005

Disadvantages• Poor abrasion resistance• Average esthetic• Technique sensitive• Susceptible to take up

additional waterHygroscopic

expansion• Susceptible to dehydration

Crazing, Cracking

Disadvantages

Wear rate Tensile strength

Conventional GI(capsule)

Metal-reinforced GI

Conventional GI(hand mix)

Development of Glass Ionomer

High viscous glass ionomer

Classification• Self-cure glass ionomer–Conventional glass ionomer • Fuji II lining (GC Co., Japan)• Ketac Fil Plus (3M ESPE, USA)

• Ketac Cem

Classification• Self-cure glass ionomer–Metal-reinforced glass ionomer• Miracle Mix (GC Co., Japan), Ketac silver (ESPE)

Classification• Self-cure glass ionomer–High viscous glass ionomer

Fuji IX (GC Co., Japan), Ketac Molar (3M ESPE, USA)

Development of Glass Ionomer

Conventional GI

Resin Components

4.5 – 6 %

Resin-Modified

GI

Resin-modified glass ionomer• Hydroxyethyl

methacrylate (HEMA)• Vitrebond, first commercial in 1989

• Acid-Base reaction + Photo-chemical polymerization–Dual-cure–Tri-cure : add autocure resin

Resin-modified glass ionomer (RMGI)Conventional GI RMGI

Vitrebond, Vitremer

Acid-base and light-polymerization reaction compete with and inhibit one

another (Berzin. et al, 2010)

Resin-modified glass ionomer (RMGI)• Improve properties

–Set on demand–Fewer desiccation and hydration problems

–Immediate finishing–Better esthetics–Tensile strength, fracture toughness

–Resistance to microleakage

–Bond to resin composite

Fuji Plus

RMGI products• Luting agent

FujiCem

Rely-X luting cement

RMGI products• Liner / Base

Fuji lining LC Vitrebond

RMGI products• Composite bonding agent–Fuji Bond LC

RMGI products• Restorative buildup

Fuji II LC

Vitremer Ketac Nano

RMGI - Restorative

GC Fuji II LC

Dentin conditioner

3M Vitremer, Ketac Nano

Primer

10% Polyacrylic acid

- 46% HEMA- 39% Ethyl alcohol- 15% Polyacrylic acid- Photoinitiator

RMGI - Restorative

Rinse

Do notRinse

RMGI - Restorative10% Polyacrylic acid37% Phosphoric acid

800x 12,000x

An atlas of glass ionomer cements, 2002

RMGI - Restorative• For Fuji II LC, 10% polyacrylic acid application is able to create micro-mechanical retention.

(Sidhu, 1999)

• For Vitremer, due to high amounts of HEMA, hydrolitic degradation of Vitremer-dentin bonds might be expected to occur. (Fritz et al., 1996)

• In term of bond durability, sealing ability, Fuji II

LC is better than Vitremer. (Fagundes et al., 2009)

Clinical using of RMGI – Class V

Clinical using of RMGI – Class V

Clinical using of RMGI – Class V

Onal & Pamir, 2005

Two years laterVitremer

Compomer

Composite

Clinical using of RMGI – Class V

Puemans et al., 2005

3-step etch and rinse

2-step etch and rinse

Glass ionomer

Survival rate

Clinical using of RMGI – Class V

Puemans et al., 2005

Failure rate

Clinical using of RMGI – Root caries

Clinical using of RMGI – Sandwich tech.

The sandwich technique with resin-modified glassionomer cements or compomers can

improve the marginal adaptation of Class II composite restorations with cervical margins located in dentine (Dietrich. et al, 1999)

Clinical using of RMGI – Sandwich tech.

Liebenberg , 2005

Clinical using of RMGI – Sandwich tech.

Liebenberg , 2005

Clinical using of RMGI – Sandwich tech.

Clinical using of RMGI• Secondary caries

F- release

Remineralization

Reduce secondary caries

Clinical using of RMGI• Secondary caries

Sidhu , 2010

Under fluoride dentifrice, the RMGI provided additional protection

against secondary caries. (Sousa et al., 2009)

Conclusion

Conclusion• Advantages

–Adhere chemically to tooth structure

–Fluoride release–Less shrinkage

• Disadvantages–Lower wear resistance and physical properties compare to composite

–Moisture sensitivity remain–Unstable color

Thank You