The clinical success of a precision impression material strongly depends on good mechanical properties of the elastomer during removal of the set impression from a patient?s mouth. A high tear resistance of the set impression material is advantageous to withstand tearing in thin interproximal areas and in the depth of the gingival sulcus and can be described by the force and the elongation which occur when the material is torn apart. This study compared the maximum force, the maximum elongation and the integral under the stress strain-curve of different VPS Wash impression materials in a tear experiment.

Hydrophilicity of precision impression materials is considered one of the most important features for clinical success. Recently, new super-hydrophilic VPS impression materials have been introduced to the market. This study aims to investigate the initial hydrophilicity of five fast set light viscosity materials in the set and, especially, the unset stage, as good performance of an impression material in both phases is necessary for the success of an indirect restoration.

Good elastic recovery after deformation is a prerequisite for the clinical success of any precision impression material. Due to the high clinical relevance of this parameter, elastic recovery and compression set are part of ISO and ADA Standards for Elastomeric Dental Impression Materials. In these standard measurements recovery is investigated after a compressive distortion. There is a lack of data regarding elastic recovery behavior of impression materials after elongation instead of compression. The goal of this study was to compare the elastic recovery of different VPS wash impression materials after elongation. Elastic recovery was determined by a measurement of the corresponding permanent deformation.