Yes, if you hope to achieve optimal and reliable cementation results. Removing contaminants from the restoration will help to achieve better bond strengths.
If the crown has been sandblasted, then after try-in, clean the internal surface of the zirconia surface with ZirClean™ and then proceed with applying a primer to the bonded surface of the restoration with a suitable primer (Z-PRIME™ Plus) according to manufacturer鈥檚 instructions.