Science and Education Publishing International Journal of Dental Sciences and Research 2 3 2014 05 19 Evaluation in Vivo of the Accuracy of Different Impression Materials 55 58 EN Msc. Kreshnik Keraj Faculty of Dental Medicine, Tirana, Albania IJDSR2014232 10.12691/ijdsr-2-3-2 2014 04 30 2014 05 13 2014 05 19 All prosthetic treatments are characterized by a sequence of well-structured clinical and laboratory steps, during which different kinds of impressions are required. The accuracy of an impression material plays an important part in the production of a well-fitting restoration and for the longevity of the restoration too. The aim of this study is to evaluate and to compare the accuracy of different impression materials, their ability to reproduce details, using a measuring microscope. Four types of impression materials were used to take the impression of the same reference points on the composite filling in the second premolar (35). Irreversible hydrocolloids: Orthoprint and Neocolloid (ZHermack), the Polyvinilsilosan: Elite HD+ and the Polyether: Permdine Garant (3M ESPEE) were used. The results show that all impression materials demonstrated greater characteristics if treated correctly before and after the impression is taken, in conformity with the respective manufacturers' guide lines and in respect to the storage time, so alginate if it's pouring into 1 hour, polyether into 4 days and polyvinilsiloxan into 2 weeks. So, we conclude that the quality and accuracy of the impression is affected by pouring and storage time in order to obtain a greater accuracy of stone casts.