Delayed Linear Expansion of Two Ultra-low Expansion Dental Stones

Abstract

The purpose of this study was to measure the linear setting expansion of two ultra-low expansion dental stones used in definitive cast/ prosthesis fabrication which claim to have very low to no setting expansion. Five specimens of each material, Zero Stone and Whip Mix Experimental, were tested using a custom expansion device as were five control samples of Silky Rock. The setting expansion of each specimen was recorded continuously for 96 hours. Data were analyzed using qualitative statistics. The results showed that there was no statistically significant difference between either stone with regards to amount of setting expansion however the test stones did significantly vary from the control. There was also no statistically significant difference in the setting expansion of the two test materials after the two hour time interval.