Influence of temperature on the dimensional stability of an addition silicone

Dental Impression Materials are used in many stages of dental prosthesis construction and can be classified as: rigid, thermoplastic, or elastic. Elastic Materials are those that remain in an elastic state after removal of the oral cavity. Addition silicones are one of the most utilized in the elastic group. Thus being, the aim of this study is to assess the influence of temperature on the dimensional stability of an addition silicone. Six casts of specimen metal were done and pairs of samples were submitted to warm (60 degrees C), cold (10 degrees C) and environmental temperature (22 degrees C). They were then measured at intervals of 1, 5, 24 and 48 hours after the printing. We experimentally proved that silicone at 60 degrees C showed the highest volumetric contraction, comparing to a slight shrinkage registered at the temperature of 22 degrees C; at the lowest temperature (10 degrees C) there were practically no dimensional changes to the models used. As temperature interferes with the dimensional stability of silicone, you need to manipulate and store it under stable conditions to ensure reliability. The shift from cast to plaster must be made as soon as possible (1 hour). When such is not possible, the best method to ensure the preservation of the dimensional stability of an impression is to place it in a refrigerated environment (for no longer than five hours).