ABSTRACT
Background: Choosing the proper impression material and the right method for a specific clinical situation, which can reproduce in an accurate way the details and dimensions of the prosthetic field, has the most important role in accomplishing fixed dentures. Material and methods: For this study we simulated a clinical situation in the laboratory using acrylic models, which helped us evaluate the differences between hydro-alginate impression and addition- cured silicones. Results: We found differences when comparing different parameters: time (2 minutes for hydro-alginates, 8 minutes for A-silicones), loss of material, dimensional stability (al- most the same), price (the price for an impression taken with A-silicones is almost double). Conclusions: The dentist has to choose the proper material and correlate it with different clinical situations and techniques used in order to obtain the best results both for him and the patient.