The comparison of dimensional accuracy of modified two-stage putty-wash condensation s polyvinyl molding method and distance two-stage putty-wash molding method

Abstract

Background and Aims: Impression in Fixed Prosthodontics is very important. An impression technique is one of the most important factors affecting the dimensional changes of die. Recent studies showed the conflicting results about the impression techniques. This study was carried out with aim of comparison two impression techniques of modified two-step putty-wash impression technique with two-step putty-wash technique with spacing. Materials and Methods: This experimental study was done on a laboratory model. 10 impression of laboratory model were taken for each technique of modifided two-step polyvinylsiloxane putty-wash impression technique and two-step putty-wash technique with spacing. Impression was poured after 30 minute with vel-mix plaster. Die's height, diameter and distance between dies were measured 6 times in laboratory model and 3 times in stone models by an expert who was not aware of impression techniques by digital coulis. Size plaster sample comparing with experimental model and result were tested by ANOVA and t-test analysis (p < 0.05 was considered significant). Results: Based on the result, there was no significant difference between two techniques in height and distance between two dies and modified impression techniques more accurate and closer to the original model. But in die's diameter there was significant difference between two techniques.Conclusion: Within the condition of this study modified impression technique is similar accuracy to two-step with spacing impression technique and in some cases modified impression technique is more accurate than with spacing impression technique. In bridges because of the more accuracy, modified impression technique can be replace instead of two-step with spacing impression technique. © 2016 by Nova Science Publishers, Inc. All rights reserved.