Crown lengthening is usually required to increase the amount of tooth structure available for a crown to grip on to firmly. This is usually done when the tooth has a short clinical crown (usually 2nd molars) to begin with, has been extensively damaged by decay or fractured due to trauma or when the decay extends under the gum close to the bone.
Crown lengthening refers to a specific type of gum surgery where bone is removed and the overlying gum is repositioned and secured with stitches to expose more of the underlying tooth structure. Other types of gum surgery include a gingivectomy where only the gum is removed. This does not require stitches afterward.
The risks of skipping crown lengthening is that the new crown may not be very secure and dislodge more easily. When this happens repeatedly, it can be very frustrating for both you and your dentist.
Other alternatives to crown lengthening:
1) Orthodontic extrusion
Braces are used to slowly pull the tooth out of the gum. This may require some brackets on the neighbouring teeth.
2) Partial extraction
For a single-rooted tooth (front teeth and some premolars), the tooth can be surgically repositioned to protrude out of the gum more instead of completely extracting it. This is quicker but more risky since the tooth may fracture during the surgical repositioning,
3) Subgingival (under the gum) crown margins
If there is a deficiency in available tooth structure only in a limited section, then placing the crown margins deeper under the gum can help to engage sufficient tooth structure. This requires skill to do correctly.
