Crown lengthening (crown exposure) procedure is required when the edge of the new crown is significantly below the gum tissue. In same cases, the new crown edge is very close to the jawbone or even below the bone.

The crown lengthening procedure removes and reshapes the gum tissue and bone around the tooth.  As a result, the edge of the crown is at or above the gum line. This procedure ensures proper fit of the crown to the tooth and provides enough tooth structure so the new crown will not become loose in the future.

The following diagrams are illustration of the Crown Lengthening Procedure.

tooth has extensive decay

The crown portion of the tooth is missing and the root remains below the gum line

The gum is pulling away from the root and bone.  High speed hand piece with round bur can remove the bone to expose more root surface

The gingiva is purposely position below the edge of the remaining root.  As a result, small portion of the root is above the gum line

Metal post is placed into the root.  Dentist can take accurate impression because the edge of new crown is either above or at the gum line

A new crown is cemented