The success in acquiring a precision impression in the dental field is a compromise between the processing time and the setting time of the impression material. A device called "Impression Heater" (EU application n ° EP20186042.6) has recently been patented, which consists of a self-heating disposable adhesive patch with an exothermic chemical reaction to be placed on the dental impression tray. The aim of the study was to evaluate the effectiveness of a thermal impression accelerator in reducing the setting time of different elastomers.