To compare and evaluate the effect of temperatures ranging from mouth temperature (37 ? C) to 50 ?C on the dimensional stability of commercially available polyvinyl siloxane impression material

Introduction: The impressions have to be transported to distant places and sometimes due to various contingencies. They cannot be poured immediately by the clinician. In such conditions regulation of temperature is a big challenge that might affect the dimensional stability of the impression material being used. An affected impression cannot produce an accurate prosthesis. The wide range of newer available elastomeric impression materials is a boon to dentistry due to its dimensional stability and accuracy under various conditions. Materials and Method: A total of 30 impressions were made to evaluate the effects of different temperatures (40 ? C and 50 ? C). The impressions were made by two step putty/light body technique. A uniform storage time of 1 hour was maintained for all the impressions. Resultant impressions were poured in stone and subjected to evaluation using travelling microscope with accuracy of 1 mm or 1µ. The control group was stored at 23 ? C for 1 hour. The control group was also poured in stone and subjected to evaluation using travelling microscope. Results: The addition silicone impression material had exceptionally good dimensional stability at different storage temperatures as compared to other elastomeric impression materials. A statistically insignificant change in dimensions of die was observed for all storage temperatures. Conclusion: It was concluded that polyvinyl siloxane maintained accuracy under all storage conditions and was dimensionally stable under adverse conditions.