Currently marketed modeling compound impression materials, and a new thermoplastic high polymer impression material, were compared in terms of their themoplastic characteristics, and their physical and mechanical properties. The twelve kinds of modeling compounds used included both Japanese and foreign products. The new material consists of poly capryl lactone. It must be softened at 72-82℃, but can be used for taking impressions at 48℃. It has higher compressive strength and Young\u27s modulus, but less elasticity than conventional modeling compounds. Its thermal conductivity in low, and its specific heat high. From these factors it is concluded that the new impression material is suitable for a variety of applications including impressions for an individual tray, for complete dentures, or for determining the occlusal relation
