In many instances, the tooth that had the root canal done and needs to get a crown is heavily damaged due to the excessive decay. Before the doctor can place the crown on such tooth, he needs to strengthen the tooth. This is done by the special restorations called “posts”.

There are two major types of posts:

  • Preformed posts are pre-manufactured posts that doctor buy from supply company. The come different shapes and sizes.
  • Cast Posts are custom made in the lab to fit the one particular tooth. They are castled from special metals, they are stronger, but require two visits to complete.

Depending of the particular conditions of the tooth doctor will decide which system of posts to use on case-by-case bases. The more of the tooth structure lost, the weaker the tooth the more chances doctor will prefer to use cast post instead of preformed.

"1"- Teeth restored with crown and CAST POST CORE
"2" Teeth restored with crown and PREFORMED POST CORE

Cast Post and Core


If the tooth is heavily decayed, the doctor may decide to use cast post core. After the tooth and canal was prepped, doctor will take impression of the tooth and send it to the lab for custom-made post and core. Some times the doctor will make acrylic pattern, which will be castled by the lab technician. The next visit received metal restoration will be cemented inside the tooth and shaped to the desired form.

Preformed post

Preformed Posts Different Shapes and Sizes

Preformed Posts


The first step is to remove some of gutta-percha, which was used to fill the canal of the tooth. Doctor will use special drills to shape the inside of canal to desired size of the chosen post. After the post is fitted, it is cemented in with special cements inside the canal. Part of the post will remain above the root. This projected part of the post along with remaining structure of the tooth, will help retain special filling material (build up), which will be placed to restore the tooth to the desired form. Besides serving as a retainer, posts strengthen the inside of the tooth, helping it to withstand forces you apply to the tooth while chewing and preventing it from breaking.

Lab processed Cast Post and Core