The effect of the surface roughness of prepared dentin on the retention of castings.

Abstract Thirty-six preparations were made from extracted teeth and divided into 3 groups. The dentin surfaces of the 3 groups were made smooth, fine, and rough. Open-top gold crowns were cast for each tooth and cemented with zinc phosphate cement. Ten samples from each group were separated twice under an axial tensile force and 2 samples from each group were sectioned for study of the cement film thickness. The reliability of the testing procedure was checked by making a set of 8 ivorine dies. No significant difference between groups was found.