Nowadays, either keeping or throwing out the final product of dental cast is the most common thing to do. The waste from dentistry can be considered toxic if not handled specifically and separately to other waste. Hence, the recycling process can reduce its effect and the waste of dental casts. It can also reduce the cost of producing new high-grade dental gypsum. This paper studies the behavior of before-after recycle and heat treatment to several grades of dental gypsum that will be used as impression material or dies. As it is designed to be an impression material that will undergo heat treatment, Simultaneous Thermogravimetry and Differential Scanning Calorimetry (TGA-DSC) will be applied to understand the Phase Transformation to its mass change and the behavior to a temperature difference. The result will be validated using an experimental approach. X-ray Diffraction (XRD) and Scanning Electron Microscope will also be done to identify the crystalline phases and the surface microstructure, and it will be validated using an experimental approach as well. A range of gaps between parameter values is expected between the fresh/new dental gypsum and the recycled one. However, it is expected some similar values between the heat-treated and the fresh/new dental gypsum.