A kit to make an individual impression tray for dental use, the kit having a standard model reproducing a dental arch, a semifinished product of thermoformable material, for example, a plate member, and a container for a heat exchange liquid. The first step that is carried out by the dentist to obtain the individual impression tray provides the insertion of the model in the container. Then, next to dental arch of the model a plate member is arranged and hereafter a certain amount of a liquid is put, for example, water, in the container up to covering plate member. The liquid is then heated by a source of thermal power, for example, a microwave oven, stopping heating when the temperature of the liquid achieves a value T* higher than the temperature for softening the thermoformable material of the plate member.
