An in-vitro study to compare the microhardness of glass ionomer cement set conventionally versus set under ultrasonic waves.

OBJECTIVE To assess the difference of surface hardness of glass ionomer cement (GIC) set by conventional setting method and under ultrasonically energized method. METHOD 20 cylindrical samples measuring 2.5mm (diameter) and 5mm (length) were prepared with type IX GIC. Ten of these samples were allowed to set by conventional setting method and other ten were set under ultrasonic excitation energy. After finishing and polishing of the samples, three indentations were made on each sample using Vicker's hardness machine with a load of 300 gm for 15 seconds. The surface microhardness of the indents was calculated by Vicker's hardness formula. RESULTS Surface microhardness of samples set by ultrasound setting method was significantly higher than samples set by conventional method. CONCLUSION This can be beneficial for the dental patients as when used as a restorative material, it will have a long lasting effect and can also be used in posterior load bearing areas.