A Acurate impression material can be obtained by choosing the right material dan good restorations results. Polyvinyl siloxane is one of the elastomer impression materials with silicone adition reaction that available in various viscosities that is low (light body), regular (medium body), high (heavy body) and very high (medium body).Polyether consists in two component systems are base and catalyst. The viscosity of this material depends on the amount of filler. The causal factor of dimensional changes particularly during impression taking is not deary elucidated yet. In this research paper will describe about the accuration differences that produced with polyvinyl siloxane and polyether for fixed dentures. This research will done by 2 different groups, first group without the used of polyvinyl siloxane and the second group with polyether. This dimensional changes are measured by the marker references that is intra-abutment and inter-abutment distance. The used of polyvinyl siloxane material done in 3 times of impression taking and polyether done also in 3 times from the model master which has been prepared in the form of two abutment. Change of distance will be measured at the die intra-abutment and inter-abutment 3 times by caliper. Independent t test were used for statistical analysis. The results show the significant value for each eight aspects are more than 0.05 (p > 0.05). From this research found that the accuration differences of the die made with polyvinyl siloxane and polyether was not significant. Polyvinyl siloxane and polyether can be used by anyone who need to have a detail and accurate information on servical surface, because it has high viscosity dan hydrophilic characteristic that make the impression materials easily flow to the impression and accurate.