Anterior full-coverage crowns require a chamfer or shoulder margin.

A circular shoulder is prepared with rounded inner edges or a chamfer at an angle of 10-30°: the width of the shoulder/chamfer is approx. 1 mm.

Facial reduction is 1.5 – 2 mm; 1 – 1.5 mm lingual contact clearance.

Incisal reduction is 1.5 – 2 mm with rounded internal line angles, and an incisal edge at least 1mm wide to permit optimum milling of the incisal edge during CAD/CAM processing

Posterior full-coverage crown requires a chamfer or shoulder margin.

A circular shoulder is prepared with rounded inner edges or a chamfer at an angle of 10-30°: the width of the shoulder/chamfer is approx. 1 mm.

Occlusal reduction is 1.5 – 2 mm: axial reduction (buccal, lingual, and interproximal) is 1.5 mm with rounded internal line angles.