Post and Core Guide: Why a Post Is Placed in a Root-Treated Tooth and How the Procedure Goes
A post and core is a treatment in which, when much of the crown of a root-treated tooth is gone, a post is placed inside the root canal and a core is built on top of it to support the crown. If enough tooth remains, only a core may be made without a post. It is done as a step before placing the crown, and the cost varies with material, method and dental clinic, so it is best to check whether it is included in the crown quote.
Key facts
| Crown after root canal treatment | For molars or heavily reduced teeth, a crown is needed to prevent fracture (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
|---|---|
| Characteristics of root-treated teeth | They break easily, so very hard food must be chewed with care (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
| Uses of composite resin | Also used to reinforce a tooth after root canal (nerve) treatment (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
| Root canal treatment visits | 3 to 4 or more visits at intervals averaging 3 to 7 days (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
| Checking for reinfection | Regular checkups including X-rays are recommended every year after root canal treatment (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
What are a post and a core?
Root canal treatment empties and fills the space where the nerve and blood vessels of the tooth were, so a tooth already heavily ground down by decay is left with thin remaining walls. If a crown is placed directly on such a tooth, there is too little to hold it and the tooth can split under chewing force.
A post is a thin pillar inserted to some depth inside the root canal, and a core is the foundation built on top of it to create the shape on which the crown sits. The post holds the core, and the core supports the crown.
- Post: a pillar placed in the root canal to hold the core
- Core: a foundation that replaces the lost crown of the tooth and supports the crown
- Crown: a cap that wraps and protects the core and the remaining tooth together
Does every root-treated tooth need a post?
No. If the remaining tooth walls are sufficient, only a core can be built from a material such as resin and a crown placed over it. The National Health Information Portal also lists reinforcing a tooth after root canal treatment among the uses of composite resin.
A post is considered additionally when the remaining tooth alone cannot support a core. If the root is short, curved or already cracked, placing a post can actually be risky, so the length and thickness of the root are checked first on X-rays.
What is the order of a post and core procedure?
After confirming that root canal treatment is finished and inflammation has settled, part of the material filling the root canal is removed and space for the post is made. There is a method of bonding a ready-made prefabricated post and building core material on top, and a method of taking an impression and casting the post and core as one piece to bond.
After the core is shaped, the process moves on to the crown, with an impression and a temporary tooth. The National Health Information Portal says root canal treatment takes 3 to 4 or more visits at intervals averaging 3 to 7 days, so the whole schedule from root canal treatment to the crown can be that much longer.
What should you be careful about after treatment?
A root-treated tooth has dulled sensation, so you may not feel it right away when you chew too hard. In the temporary state before the crown is placed, especially, do not chew hard or tough food on that tooth.
Even after the crown is placed, if the root cracks vertically it may be hard to save the tooth. If the gums suddenly swell or only one side feels sharp when biting, have it checked without delay. The National Health Information Portal recommends regular checkups including X-rays every year to see whether a root-treated tooth has become reinfected.
What materials are there for posts and cores?
Posts are mainly metal or fiber hardened in resin, and cores are built from resin-type materials or cast in metal. Fiber posts are light in color, so they are less likely to show through under ceramic crowns, and cast metal post-and-cores are chosen because they make it easy to match the shape when very little tooth remains.
Which material suits depends on the thickness and length of the root, the height of the remaining tooth walls, and the crown material to go on top. Because how hard a post is to remove differs by material when the tooth later needs root canal treatment again, hearing the reason for the choice makes it easier to understand later treatment plans.
Common myths and facts
Myth: Placing a post makes the tooth stronger.
The role of a post is to hold the core and crown, not to strengthen the root itself. That is why, if enough tooth remains, building only a core without a post is considered first.
Myth: After root canal treatment is done, the crown can wait until later.
The National Health Information Portal explains that root-treated teeth break easily and need a crown if they are molars or heavily ground down. If put off for long, the tooth can break and have to be extracted.
Frequently asked questions
Is the post and core cost included in the crown cost?
It differs by dental clinic. Asking separately at the consultation whether the core is in the crown quote and whether placing a post adds cost avoids differences later.
Does placing a post hurt?
The nerve inside the tooth has already been removed by root canal treatment, so pain is usually not great. However, anesthesia is sometimes given when working close to the gums or when surrounding tissue is sensitive.
How do prefabricated posts and cast posts differ?
A prefabricated post is a pillar made in advance that is bonded and the core built up, often finishing the same day. A cast post and core is made as one piece to fit the tooth from an impression, so one more visit is needed.
Are posts placed in front teeth too?
Front teeth are thin at the crown, so a post may be considered when little tooth remains after root canal treatment. A material close to tooth color is sometimes used to reduce show-through of the crown color.
My crown came out and the post came out with it.
Keep what came out as it is and take it to the dentist right away. If the root is not cracked it can be bonded back, but if the root has split, other options including extraction may need to be discussed.
Related topics
- Crowns, Bridges and Dentures
- Crowns, Bridges and Dentures
- Root Canal Treatment Process
- Crown Material Comparison
- Pain After a Crown