Dimensional Stability of Non-Aqueous Elastomeric Impression Materials

Part 1. The Measurement of Polymerization and Thermal Contractions of Commercially Available Products by a Non-Pressure Method

Abstract

　The polymerization and thermal contractions of 39 products of non-aqueous elastomeric impression material recently available were directly measured by a non-pressure method.
　The polymerization contraction of each material generally agreed with the theory of polymerization reaction of the materials. The tendency of polymerization and thermal contractions depended upon the products in regular and injection types, while the contractions of putty type were less than those of the other types.
　The results indicated that the thermal contraction of elastomer was an important factor affecting the accuracy of the stone-die, since a large amount of the thermal contraction was found compared with the polymerization contraction.