Knife Edge (Feather Edge) Finishing Line
Posted on 08/08/2011
Over the next several blog posts, we will discuss various finishing line styles of tooth preparations and the restorations that are ideal for each style.
Knife Edge:
The knife edge finishing line has historically been used exclusively for metal margins. The advantage of this prep is that it can go deeply subgingival to give added retention especially on short preps. The disadvantage was, until recently, that there was no all ceramic option. This changed with the introduction of the full contour zirconia crowns (also known as Bruxzir crowns by Glidewell) which require no porcelain build up. Since porcelain requires a shoulder or chamfer "shelf" to support it, porcelain knife edge margins were known to fracture. However, the full contour zirconia margins can be made very think similar to a full cast crown.
Knife Edge:
The knife edge finishing line has historically been used exclusively for metal margins. The advantage of this prep is that it can go deeply subgingival to give added retention especially on short preps. The disadvantage was, until recently, that there was no all ceramic option. This changed with the introduction of the full contour zirconia crowns (also known as Bruxzir crowns by Glidewell) which require no porcelain build up. Since porcelain requires a shoulder or chamfer "shelf" to support it, porcelain knife edge margins were known to fracture. However, the full contour zirconia margins can be made very think similar to a full cast crown.
