This document discusses glass ionomer cement and resin-modified glass ionomer cement in restorative dentistry. It describes the composition and setting reactions of glass ionomer cement, as well as its advantages like adhesion to tooth structure, fluoride release, and low shrinkage. However, it also notes disadvantages like poorer wear resistance and physical properties compared to resin composites, as well as ongoing moisture sensitivity issues. The document then discusses how resin-modified glass ionomer cements were developed to improve properties like strength and reduce moisture sensitivity issues. It concludes by describing clinical applications of resin-modified glass ionomer cements, such as for class V restorations, root caries treatment, and the sandwich technique.

1. Glass Ionomer in Contemporary Restorative DentistryBy RoojRojasawasthien. DDS, MSc.16 August 2010

2. Direct Tooth Colored MaterialResin compositeCompomer (Polyacid Modified Resin)Glass IonomerResin Modified Glass Ionomer

3. Direct Tooth Colored MaterialIMCRIonomer-ModifiedComposite Resins(fluoride in resin)CRComposite Resins(glass-containingHydrophobic resins)PAMRPolyacid-ModifiedResin (compomer)RMGIResin-ModifiedGlass IonomersGICGlass IonomerCements

4. Glass IonomerSilicate cements ---> Glass ionomer(Wilson and Kent, 1972)Powder + LiquidFluoroaluminosilicate glass + Polyalkenoic acidAcid – Base reaction

5. Phase I (Ion-leaching phase)Polyacid extracts ions from glass powderMixing - Shiny, GlossyPhase II (Hydrogel phase)Ion cause formation of polyacid matrixSetting (3-6 min) - Rigid, OpaquePhase III (Polysalt gel phase)Silica gel forms and attaches powder to matrixMaturation (24 hrs – 1 yrs) More tooth-like color

6. Fully set Glass Ionomer

7. AdvantagesLess shrinkage than polymerizing resinNo free monomers, Non-irritating to pulpCoefficient of thermal expansion similar to dentinHigh compressive strength

8. AdvantagesAdhere chemically to enamel and dentin (hydrophilic)

9. AdvantageFluoride release and recharge (reservoir effect)Delbem et al., 2005

10. DisadvantagesPoor abrasion resistanceAverage estheticTechnique sensitiveSusceptible to take up additional waterHygroscopic expansionSusceptible to dehydrationCrazing, Cracking

11. DisadvantagesWear rateTensile strength

12. Development of Glass IonomerConventional GI(capsule) Conventional GI(hand mix) Metal-reinforced GIHigh viscous glass ionomer

13. ClassificationSelf-cure glass ionomerConventional glass ionomerFuji II lining (GC Co., Japan)KetacFil Plus (3M ESPE, USA)KetacCem

14. ClassificationSelf-cure glass ionomerMetal-reinforced glass ionomerMiracle Mix (GC Co., Japan),Ketac silver (ESPE)

15. ClassificationSelf-cure glass ionomerHigh viscous glass ionomerFuji IX (GC Co., Japan), Ketac Molar (3M ESPE, USA)

16. Development of Glass Ionomer

17. Resin-modified glass ionomerHydroxyethylmethacrylate (HEMA)Vitrebond, first commercial in 1989Acid-Base reaction + Photo-chemical polymerizationDual-cureTri-cure: add autocure resin

18. Resin-modified glass ionomer (RMGI)Conventional GIRMGIVitrebond, VitremerAcid-base and light-polymerization reaction compete with and inhibit one another (Berzin. et al, 2010)

19. Resin-modified glass ionomer (RMGI)Improve propertiesSet on demandFewer desiccation and hydration problemsImmediate finishingBetter estheticsTensile strength, fracture toughnessResistance to microleakageBond to resin composite

20. RMGI productsLuting agentFuji PlusFujiCem Rely-X luting cement

21. RMGI productsLiner / Base Fuji lining LCVitrebond

22. RMGI productsComposite bonding agentFuji Bond LC

23. RMGI productsRestorative buildupFuji II LCVitremerKetacNano

24. RMGI - Restorative GC Fuji II LCDentin conditioner 3M Vitremer, KetacNanoPrimer 46% HEMA

25. 39% Ethyl alcohol

26. 15% Polyacrylic acid

27. Photoinitiator10% Polyacrylic acid

28. RMGI - RestorativeRinseDo notRinse

29. RMGI - Restorative10% Polyacrylic acid37% Phosphoric acid12,000x800xAn atlas of glass ionomer cements, 2002

30. RMGI - RestorativeFor 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. (Fagundeset al., 2009)

31. Clinical using of RMGI – Class V

32. Clinical using of RMGI – Class V

33. Clinical using of RMGI – Class VCompomerTwo years laterVitremerCompositeOnal & Pamir, 2005

34. Clinical using of RMGI – Class VSurvival rate3-step etch and rinseGlass ionomer2-step etch and rinsePuemans et al., 2005

35. Clinical using of RMGI – Class VFailure ratePuemans et al., 2005

36. Clinical using of RMGI – Root caries

37. 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)

38. Clinical using of RMGI – Sandwich tech.Liebenberg , 2005

39. Clinical using of RMGI – Sandwich tech.Liebenberg , 2005

40. Clinical using of RMGI – Sandwich tech.

41. Clinical using of RMGISecondary caries

42. Clinical using of RMGISecondary cariesSidhu , 2010Under fluoride dentifrice, the RMGI provided additional protection against secondary caries. (Sousa et al., 2009)