Influence of impression materials on choice of dental stone and improved dental stone

The surface hardness and compressive strength of dental stone and improved dental stone were investigated when crystallised in contact with impression materials. Vickers hardness tests were performed at 45 min, 2 h and 24 h, and compressive strength tests were performed at 24 h after the beginning of stone mixing. For the surface hardness of stone models, the impression material type, stone type and measurement time were found statistically significant (p<0.001) and for the compressive strength, the impression material type and stone type were found statistically significant (p<0.001). Within the measurement times, the hardness values were statistically different from each other. The highest hardness values were obtained from the 24 h measurements, followed by the 2 h measurements, while the lowest hardness values were obtained from the 45 min measurements. Specimens obtained from improved dental stone showed higher hardness values and compressive strength than those from dental stone.