Rheological Properties of Some Materials Used for Dental Impression

Abstract

The dimensional stability of dental impression materials is one of the variables that contribute to the accuracy or to the inexactitude of dentures. The rheological properties of several dental impression materials were determined by amplitude and frequency sweep tests. Deformation, storage modulus G’, loss modulus G” and complex viscosity η^* were studied for each sample. Moreover, the texture, the stability of the shape, the capacity of distribution on different surfaces and the stability to storage for a long period of time were investigated. All these samples, characterized by a gel structure with G’>G”, are suitable as impression materials. Irreversible hydro-colloids) may be used for different kind of impressions because of their fidelity and elasticity; they also present medium time elasticity and may be easily prepared.