[The porosity, microhardness, roughness and internal stresses of PMMA base materials in relation to their isolation. 1. Porosity and microhardness].

Selected material properties of hot and cold polymerized denture basic materials (polymethylmethacrylate) were investigated after different methods of isolation: alginate, tin foil and silicone. Both tin foil and silicone isolation the handling of which is much easier result in a decreased portion of porosities and an increased microhardness in the PMMA.