Impression heater: effectiveness of the thermal accelerator of dental impressions.

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.