Scanners have advanced to the point where they are able to capture anatomical details on the micron level, enabling incredibly accurate restorations and reduced refabrication rates. Since intra-oral scanning requires full margin visibility, digital scans benefit most from shoulder/chamfer prep styles.
Best Margin Types for Digital Dentistry:
Shoulder Prep is Best!
When prepping with a shoulder, the margin is clearly visible on the scan - ensuring the restoration matches perfectly to the finish-line.
Chamfer prep is Acceptable.
While similar to shoulder preps, they limit the space needed to create adequate material thickness on the marginal region.
Shoulder Bevel is Less Than Ideal, but Acceptable.
These preps lend to higher rates of open/shy margins due to their shape and the increased room for error when attempting to get the margin flush with the restoration.
Knife/Feather Edge are Not Suitable.
These preps limit the space needed to create adequate material thickness on the marginal region.