Effect of Nano Filler on Microhardness, Diametral Tensile Strength and Compressive Strength of Nano-Filled Glass Ionomer

Aim: This study was designed to evaluate the microhardness, diametral tensile strength and compressive strength of a nano-filled glass ionomer restorative material in comparison with a resin modified and conventional glass ionomers. Materials and Methods: A total of 45 specimens were prepared from three types of glass ionomer restorative materials. Specimens were cured with a light curing unit according to the manufacturer's instructions. The specimens were prepared using Teflon split molds with dimensions of 6 mm height and 4 mm diameter. Incremental curing in 3 layers, 2mm each were used. After curing, all specimens were immersed in distilled water for 24 hours. Microhardness test was done using a Vickers microhardness Tester with 25 gf load for 5 sec. Diametral tensile strength and compressive strength were measured using Intestron testing machine at cross-head speed of 50 gm/ sec until fracture. Results: There was a significant difference among the tested materials in all testing parameters. Ketac fil Aplicap exhibited the highest hardness value while Glass carbomer fil GCP has the lowest value while GC Fuji II LC showed intermediate micro-hardness value. GC Fuji II LC exhibited the highest diametral tensile and compressive strength values while Ketac Fil Plus Aplicap has the lowest values. Glass Carbomer Fil, GCP showed intermediate diametral tensile and compressive strength values. Conclusions: The nano-filled glass ionomer (Glass Carbomer Fil, GCP) exhibited the lowest hardness value, intermediate diametral tensile and compressive strength values.