Effect of salivary films on the surface properties of elastomeric impression materials

Impression materials exposed to the oral cavity are subjected to spontaneous adsorption of salivary films. The aim of this study was to evaluate the effect of adsorbed salivary films on some surface properties of one condensation, four addition silicone and one polyether impression materials. The results showed that adsorbed salivary films caused an increase in the critical surface tension and in the polarity ratios for all materials tested. A reduction in the number of voids in die stone casts was also noticed, along with an improvement in the gypsum compatibility with the impression materials tested. It can be concluded that the presence and effect of salivary films should be taken into consideration when studying the surface properties of elastomeric impression materials.