Wettability of a hydrophilic addition silicone impression material.

Silicone impression materials, long noted for their poor wettability, have typically demonstrated contact angles with water greater than 90 degrees. This study compared the wettability of a new hydrophilic addition silicone with that of other impression materials. Specimens from various viscosities of polyether, polysulfide, hydrophobic addition silicone, and hydrophilic addition silicone were formed against a smooth surface. The advancing contact angle of a saturated aqueous solution of CaSO4 on the impression materials was measured after 1 minute. Mean contact angles were calculated and results were analyzed by ANOVA and a multiple comparison of means procedure. Differences between pairs of contact angle means were found to be statistically significant except for the polyether-hydrophilic addition silicone pair. The wettability of the hydrophilic addition silicone impression material was found to be not significantly different from that of a polyether impression material.