Dimensional accuracy and bond strength of addition silicones.

A cross-matching study was conducted to evaluate the effect on dimensional accuracy and tensile bond strength between the materials when intermixing brands of addition silicone impression materials in a putty-wash impression. Three brands of putty-wash systems (Reprosil, Permagum, and Express), which formed nine possible combinations, were involved in this study. The dimensional accuracy was estimated from stone casts recovered from impressions of a standardized stainless steel master model. Findings indicated no adverse effect on the bond between putty and light-bodied materials of different brands. Statistical analysis indicated significant differences. However, because the actual differences in percent deviations between the intermixed groups and their respective reference groups are very small, they are presumed to be insignificant clinically.