Primero crowns have a two layer build-up, like natural teeth, that consist of a core of cervical dentin color, covered by an almost clear incisal. The color of a natural tooth is mainly due to the dentin core, and the color is like it “comes from within“. During CAD design the dentin-enamel interface (GBO), which location depends on the age of the patient, needs to be considered, also called “histo-anatomic” design. The interface shows a definite “S-curve” on the palatal side of the crown.