What is the recommended margin design for a porcelain jacket crown?

The recommended margin design for a porcelain jacket crown is a shoulder or butt joint. This design is crucial because it provides a well-defined and stable area for the crown to seat entirely against the tooth preparation. A shoulder margin creates a flat, horizontal platform, which enhances the aesthetics and allows for a precise fit and strong bonding of the porcelain to the underlying tooth structure.

This type of margin is particularly beneficial in achieving excellent esthetic results since it facilitates the proper contour and thickness of the porcelain material. It helps minimize the risk of fracture and chip-off at the margins, which can compromise the integrity and longevity of the crown. Additionally, the shoulder margin aids in maintaining the gingival health around the crown by ensuring that there are no areas where plaque can accumulate due to inadequate margins.

The other margin types, while used in different scenarios, do not provide the same level of adaptation and are not generally recommended for porcelain jacket crowns. A chamfer joint, for example, is more appropriate for certain types of metal crowns, while a bevelled edge is often used when space is limited or for specific indications. The feather edge, though it offers minimal tooth reduction, lacks the stability required for supporting porcelain. Thus, the shoulder or butt joint remains the optimal choice for achieving