Zeno is layered porcelain fused to zirconia that is hypoallergenic, biocompatible, and has high flexural strength. Zeno offers the strength of PFM while eliminating esthetic challenges such as bright, opaque reflection or dark shadow lines that appear apical to margin. Through the advances of CadCam technology, they provide consistently accurate fits. Due to zirconias natural translucency, the crowns are warmer and provide superior life like coloration when compare to PFM counter parts. Zeno is a great choice for anterior or posterior cases, crown over implants, and up to 8 unit bridges. It is not recommended if a patient has broke a PFM crown previously or on a case that requires bonding.
A shoulder prep is not needed, a mild chamfer or feather edge margins is adequate. For buccal, lingual, and occlusal reduction 1mm is ideal, but can go 0.5mm in some areas where further reduction is needed.