EFFECT OF THERMOCYCLING ON SHEAR BOND STRENGTH OF GLASS IONOMER CEMENTS.

To evaluate the effect of thermocycling on shear bond strength of Fuji IX glass ionomer cement and a novel glass ionomer cement (Ketac Universal) to dentin. A total of 40 extracted human molars were divided into 4 groups (n = 10). The occlusal surfaces were ground flat to expose dentin using diamond discs. Dentin surfaces were treated according to manufacturers' instructions, and restorative materials were applied onto a plastic mold of 3mm height and 4mm diameter. The shear bond strength of Ketac Universal and conventional Fuji IX glass ionomer cements was evaluated after 24 h using Instron Universal Testing Machine at a crosshead speed of 0.5 mm/min before and after the specimens were subjected to thrmocycling. There was no statistical difference in the shear bond strength of Ketac Universal and Fuji IX glass ionomer cement before thermocycling. However, after thermocycling, Fuji IX GIC showed significantly higher shear bond strength. Thermocycling affected the shear bond strength of the two glass ionomer cements tested. Fuji IX demonstrated significantly higher shear bond strength as compared to Ketac Universal when subjected to thermocycling. [ABSTRACT FROM AUTHOR]