IPS Empress CAD - HT Block, Shade A1 Size I12, 5/Pk. IPS Empress CAD is a system of composite (leucite-based) ceramic blocks that are commonly used for CAD/CAM dental restorations using CEREC and inLab systems. HT blocks feature a high degree of translucency, making them ideally suited for the fabrication of smaller restorations (e.g., inlays and onlays). Package of 5 blocks