This study evaluated and compared the shear bond strengths of seven different self-adhesive resin cements [Maxcem (MA), Smartcem (SM), Unicem (UN), Breeze (BR), Biscem (BI), Set (SE), Clearfil SA luting (CL)] and one conventional resin cement [Resicem (RE)] with four different surface treatments [#600 polishing, phosphoric acid etching, one-step self-etch adhesive (G-bond) and phosphoric acid + one-step self-etch adhesive (PG)] to human enamel. Marginal leakage was evaluated using the stain infiltration method. Results showed the shear bond strength of enamel to MA, UN, BR, BI, SE, CL and RE specimens in ascending order were #600 polishing < one-step self-etch adhesive < phosphoric acid etching < phosphoric acid + one-step self-etch adhesive. Marginal leakage was observed in all specimens treated with #600 polishing except for CL specimen, but phosphoric acid etching and G-bond treatment effectively prevented marginal leakage.

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The cushioning effects of ten casting ring liners on the setting expansion of the investment materials in split metal molds, 30mm in inner diameter and 40mm in height, were evaluated based on a decrease in the thickness of the liners. The ceramic liners were placed to completely cover the inner surface of the casting ring. Setting expansion of the investment material was 0.193%, and the required decrease in the thickness of liners was calculated as 0.027 to 0.028mm. Measured decrease values in the thickness of liners (δTs) were in a range from 0.022 to 0.137mm. δTs at the bottom part of the mold were larger than those at the upper part for three liners. δTs were larger than the required value for eight liners.

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