What is the appropriate preparation margin design for the INCISAL edge when preparing for a porcelain veneer?

A shoulder (butt joint) margin is recommended for the incisal edge of porcelain veneers. The shoulder provides a defined margin for porcelain to terminate against, allows adequate material thickness for strength and esthetics at the incisal edge, and allows precise fit. A knife-edge at the incisal provides inadequate material thickness. The cervical margin of veneers typically uses a chamfer or featheredge.