Impression heater: effectiveness of the thermal accelerator of dental impressions

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.

Three samples of 5 different elastomeric materials (width 6 mm x length 50 mm x depth 3-5-7 mm) the hardening of the material was evaluated at intervals of 15 seconds using an ASTM 2240 Shore-A durometer at 20 °C. The same procedure was replicated 3 times after positioning on a Impression Heater at temperatures of 35 °C, 50 °C and 65 °C, for each material.

An increase in the impression material temperature from 35 °C to 50 °C reduces the setting time of an amount between 38.1% and 45.8%. Increasing the temperature from 35 °C to 65 °C results in a reduction of the setting time between 52.4% and 66.9%. At higher temperatures, the greater thickness of the impression material requires longer hardening times.

The tests carried out confirm the validity of the patented idea which reduces the time of impression taking while keeping the working time sufficiently long for the operator to manoeuvre.