5. Phase I (Ion-leaching phase)Polyacid extracts ions from glass powder Mixing - Shiny, Glossy Phase II (Hydrogel phase)Ion cause formation of polyacid matrix Setting (3-6 min) - Rigid, Opaque Phase III (Polysalt gel phase)Silica gel forms and attaches powder to matrix Maturation (24 hrs – 1 yrs) More tooth-like color
7. Advantages Less shrinkage than polymerizing resin No free monomers, Non-irritating to pulp Coefficient of thermal expansion similar to dentin High compressive strength
10. Disadvantages Poor abrasion resistance Average esthetic Technique sensitive Susceptible to take up additional water Hygroscopic expansion Susceptible to dehydration Crazing, Cracking
18. 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)
19. 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
29. RMGI - Restorative 10% Polyacrylic acid 37% Phosphoric acid 12,000x 800x An atlas of glass ionomer cements, 2002
30. 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. (Fagundeset al., 2009)
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)
42. Clinical using of RMGI Secondary caries Sidhu , 2010 Under fluoride dentifrice, the RMGI provided additional protection against secondary caries. (Sousa et al., 2009)