RESIN MODIFIED GLASS-IONOMER CEMENTS - IN-VITRO MICROLEAKAGE IN DIRECT CLASS-V AND CLASS-II SANDWICH RESTORATIONS

Microleakage of conventional chemically cured and resin modified glass ionomer cements (GIG), a compomer and a composite resin was studied i n vitro in direct class V and class II GIC/composite sandwich fillings . None of the restorative techniques investigated completely resisted microleakage at both the occlusal and gingival margins. The dentinal g ingival margins exhibited the highest leakage pattern. The compomer an d the resin modified GIC showed a better seal than the chemically cure d GIC's. The use of a liner as separating agent between composite resi n and GIC in the class II sandwich fillings did not improve the seal. The results suggest that the initial bond obtained immediately after l ight curing of the resin modified GIC's is stronger than that for chem ically cured GIC's. The contradictory results of dye leakage studies r eported in the litterature are discussed and in vivo evaluations are s uggested necessary to predict clinical performance.