How do monolithic zirconia crowns differ from layered zirconia crowns?

• A. Monolithic crowns are a single material without veneer porcelain; layered crowns have porcelain veneer for esthetics but are more prone to chipping.
• B. Monolithic crowns require veneer porcelain; layered crowns are a single material.
• C. Monolithic crowns incorporate a metal substructure.
• D. Layered crowns have no porcelain veneer and rely on monolithic core.

Answer: (A)

Monolithic zirconia crowns are milled from a single block of zirconia with no porcelain veneer attached. Layered zirconia crowns, on the other hand, have a zirconia core with a porcelain veneer applied for esthetics. That veneer adds a fragile layer at the veneer/core interface, making layered crowns more prone to chipping or delamination compared with monolithic crowns. So the best description is that monolithic crowns are a single material without veneer porcelain, while layered crowns include a porcelain veneer for esthetics but carry a higher risk of veneer chipping.