Ferrule Effect: What Is It?

ferrule effectDuring your dental appointments, your dentist may use some terms that you don’t understand. Even after they explain it, you may still be a little unclear. Here’s one term you may hear if you have a damaged tooth.

What Is the Ferrule Effect?

This term refers to the need to have several millimeters of sound tooth structure left above the bone (alveolar bone) to decrease the risk of a tooth fracturing after certain procedures that require a crown, such as a root canal. A tooth may require a root canal if it has deep decay, a fracture, or a large restoration close to the pulp. The root canal procedure is meant to help retain your tooth’s function, but it may leave very little natural tooth structure remaining.

An amount of sound tooth structure should be above the alveolar bone and soft tissue, explains research in the Balkan Journal of Dental Medicine. This leaves space for the soft tissue to attach to the tooth and space for the ferrule or crown. In cases where there isn’t much of the tooth remaining, you may need a surgical procedure called crown lengthening. During this procedure, the oral surgeon removes tissue and bone to expose enough tooth structure above the bone.


Placing Your Restoration

To allow for the ferrule effect, your dentist will insert a post into the root canal system. A core extends off the post. Your dentist will shape the tooth material appropriately with a bur on a high-speed hand piece, and then the crown can be cemented onto the tooth and post.


Why Ferrule Effect Is Important

Teeth or crowns may flex or move. This movement can lead to fracture. The ferrule effect helps reduce the risk of the tooth fracturing, though it doesn’t guarantee it.

A solid tooth foundation is necessary so that a crown has its finish margin on natural tooth structure. Sometimes, even with surgery, the tooth may not have enough available tooth structure to allow for crown placement. In these cases, the dentist can’t use a crown to restore the tooth’s function and the tooth may need to be extracted. To prevent the possible loss of your teeth, make sure to keep up with a daily oral hygiene routine.