To easily remove an impression material without damaging a plaster prototype when the impressing material in which the plaster prototype is formed, is removed from a tray by a method wherein the tray for a dentition impression is formed of a Ni-Ti based or a Ni-Ti-Cu based shape memory alloy of which the shape recovery starting temperature is a specified value.
This tray for a dentition impression is a tray 1 having a U-shaped cross section on which a plurality of small holes are made, and in the tray 1, an impression material such as silicon rubber is arranged, and by holding a handle 2 which is attached to the tray 1, the impression material is placed on the dentition part in the oral cavity of a patient, and by pressing the impression material, an impression of the dentition is obtained. In this case, the tray for the dentition impression is formed of a Ni-Ti based or a Ni-Ti-Cu based shape memory allay of which the shape recovery starting temperature is 40°C or higher. By this method, by heating the tray to a temperature which is 40°C or higher, the tray 1 is deformed in the opening direction, and the impression material after an impressiontaking can be easily removed without damaging thin and fragile spots of a plaster prototype inside.
SHIROYAMA KAISUKE
KONO ATSUSHI
HIRANO SUSUMU
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