PlastSeal is an easy-to-use temporary filling resin.Its benefits are: (1) quick filling with simple brush-on-technique right after cavity preparation, and (2) easy removal in one piece with an explorer.Its outstanding benefits differing from conventional temporary filling materials are: (3) excellent sealing ability by administration of the patented Abietic Acid, and (4) elasticity for smooth insertion of an explorer and easy removal without damaging preparation margins even when slight undercuts are present.(1)Microleakage test by Ag+ penetration after thermal cycle at 60°C and 4°C, 50 times, showed excellent sealing ability for PlastSeal both at the enamel and the dentin margins, while the other com. available products showed extensive amount of leakage.PlastSeal exhibited the lower resistance in an explorer insertion test and the more elastic property in a shore hardness test than the conventional temporary filling resins.Unpolymerized monomer released from PlastSeal was significantly less than that from an imported temporary filling resin.Exothermic temperature of PlastSeal on polymerization was significantly lower than those of compared products, and the least affects are expected on the living dentin-pulp complex.It is concluded that PlastSeal meets the ideal clin. standards requested for temporary filling, and its excellent clin. performance is expected.