Post & Core

Post & Core

A post and core is a dental restoration used to sufficiently build-up tooth structure for future restoration with a crown when there is not enough tooth structure to properly retain the crown, due to loss of tooth structure to either decay or fracture. Post and cores are therefore referred to as foundation restorations.

The post itself is a reinforced fibre structure that is placed within the root of a tooth that has had a root canal (endodontic procedure). When a root canal is performed, the nerve is removed and the space it occupied is filled with a special filling material.

In placing a post, we remove some of this root canal filling material creating a space. The space that is created is used to anchor the post within the root of the tooth.

The type of post that is chosen will depend upon a number of factors. Most posts used today are prefabricated. The appropriate size is selected depending on the tooth.

A core is built from filling material around the part of the post that sticks out of the root after the post is cemented into the root. The core is shaped so that it will anchor and retain a crown.

Although posts are usually recommended when there is minimal support for a crown, they are not always necessary. The use of a post is determined on an individual basis based upon support and structural strength required.

Structure

A post and core consists of two parts :

Post : The post is a small rod, usually metal, that is inserted into the root space of the tooth and protrudes from the root a couple of millimetres. The post is then used to hold the core, or a filling in place.
Because the post is inserted into the root canal, a post and core can only be made for a tooth that has had root canal treatment.
Core : The core replaces missing tooth structure in preparation for making a new dental crown. Normally, a dental core can be directly built up from composite materials without a post to hold it in place. However, a dental post can be used to help to anchor the core to the tooth. In this case, the core is generally made off metal alloys and the device is called post and core. The core is then utilized to hold a dental crown in place. The crown can be a single unit crown or a retainer crown for a dental bridge.

Procedure For Post And Core

Deciding Post in the Root or Not - The decision to place a post in the root canal is based depending on the amount of tooth structure remaining above the gum line. If sufficient amount of tooth structure is present above the gum line and a small access cavity is present, then there is no need for placement of post. The tooth is just filled with a filling material and crown is placed over it if it is required.

But if large amount of tooth structure is missing above the gum line, a post has to be placed inside the root canal so that crown can be retained properly over it.

Procedure For Post And Core Placement