A cast post and core is a dental procedure that is meant to restore damaged tooth structure after a root canal so that a crown can be placed over it. It is one of three options that can be used to replace missing tooth structure after a root canal and before making a crown.
Without this procedure, you would not be able to fit a crown over your tooth. Basically, it is required in order to make the tooth cap last for as long as possible.
Table of contents:
Overview
Teeth with large cavities often end up needing root canals. After all of the decay and infected pulp has been excavated, a lot of the tooth structure will be missing. If your dentist puts a crown over the tooth in this state, it would never last.
If you wanted to extend the longevity of the crown, you should get a post and core completed prior to restoring the tooth with a crown. The post rebuilds the lost tooth structure so that it can fit the crown. It is essentially a metal piece that gets glued into your tooth.
What it looks like
The cast post and core is one piece but you can think of it as two separate components combined into one.
Core portion. This is the bulk of the cast post and core, it is the part that sits in the pulp chamber and above the gum line. It's purpose is to replace missing tooth structure.
Post portion. This is component which looks like a stick and it is inserted down into the canal of the root. It's purpose is to provide retention for the core portion.
Video
This is a video demonstration to give you a better idea of what a cast post and core looks like. Images alone don't do it justice and won't give you the best visualization.
Material
As its name implies, a cast post and core is made of a mixture of metal, thus will look metallic. However, you may request to have some gold mixed into it if you wanted it to be less metal looking.
Appearance on x-ray
The cast post looks extremely radiopaque on x-rays. You can see it extend down into the root. However, in the x-ray above it was not done correctly because the post actually caused a root perforation.
When it's needed
A cast post and core is needed after a root canal if a LOT of tooth structure is missing. The purpose of it is to replace all of the missing tooth structure with the core. The post part is to provide retention for the core since it goes deep into the canal.
If your tooth did not have a root canal, this procedure would not be needed. It only works on teeth where they no longer have a nerve since the post portion is cemented into the nerve canal.
Do I need a crown afterwards?
After the cast post and core is glued into the tooth, you will have a lot of metal showing. That will ruin your smile if you don't cover it up with a crown so yes, it is required afterwards.
The ceramic or porcelain crown will cover over the entire tooth so that no unsightly metal will show through. Besides, the procedure isn't meant to restore the tooth to its original shape and contour completely. It was only meant to restore it to a shape that is suitable for a crown to be placed on it.
Video
This is a video demonstration to show you what a cast post and core in addition to crown looks like.
Cast post and core technique
Your dentist has two ways of making the cast post and core, one is the direct method and the other is the indirect method. They are differing ways of how to relay information to the dental lab for fabrication of the prosthetic part. After it returns from the lab, your dentist can permanently cement it into the tooth.
Direct method
The direct technique involves preparing the post space by removing some of the root canal filling (gutta percha) and then placing a plastic pin inside of the canal.
Then your dentist will add a pattern resin to the pin to try to capture the shape of the canal and the tooth. Once this is completed, your dentist will send this plastic pin with the patten resin attached to it to the dental lab.
If you prefer a visual reference, here is a video by one of our colleagues, Dr Clark Chen, demonstrating how it is done on a typodont model:
Indirect method
The indirect technique involves preparing the post space just like the direct method. The only difference is that your dentist will place the plastic pin inside of the canal and then take an impression of the canal and the tooth.
This impression will get sent to the lab for fabrication.
What to expect for procedure
The entire cast post and core procedure will take a total of two visits to complete.
First visit - involves preparing the post space and taking an impression (indirect technique) or sending a pattern of the post space (direct technique).
Second visit - the fabricated cast post will return from the lab. This is the try-in and cementation appointment for the post if it fits.
After it has been successfully glued in, the patient may begin their crown appointment. Some dentists like to do this on the same day as the cementation while others like to have the patient return for a separate appointment.
Do I need to be numb?
It's not necessary to be numb for this procedure since it is typically done after a root canal. That means the tooth no longer has any nerves so you shouldn't feel any pain nor discomfort even while your dentist is drilling on it.
However, if you do feel squeamish you may request local anesthesia from your dentist.
Aftercare
There are no special aftercare instructions for this procedure because a crown is placed over the entire tooth to protect it. You can eat with it and speak with it as if it was your natural tooth.
Essentially you can treat it as if it was any other tooth in your mouth. Brush it and floss it twice a day which is what you should be doing as a normal part of your oral hygiene routine to keep your mouth healthy.
Complications
Every procedure comes with risks and benefits so this one is of no exception. Mishaps can occur and studies have demonstrated that there is a chance for restorative failure.
Possible complications:
Tooth fracture. The cast post core is supposed to strengthen the tooth be restoring damaged tooth structure but sometimes it can still fail. Studies have shown that the tooth or root can fracture afterwards.
Metal show through. Since it is made of metal, sometimes the metallic color can show through the crown. The tooth will still be functional but it will be an aesthetic failure.
Crown falls off with post attached. If there isn't enough natural tooth structure, this procedure may not be retentive enough to retain the crown. Sometimes the entire crown and post complex can fall out.
Tooth decay. The metal post may not get cavities but the natural tooth structure next to it can still become carious.
When to see a dentist
If you experience any of the complications above, you should see a dentist immediately. No home remedy will be able to fix any of those conditions.
Potential treatments:
New crown
Extraction with implant
Redo post with crown
Cost
The average cost of a cast post and core is $430.52 without dental insurance. That includes both visits and the lab bill that comes with it. The reason why this costs more than the prefab post and the core build up is due to the associated lab bill.
Cost with insurance
The approximate cost of a cast post and core with dental insurance is $86.10 and that is with 80% coverage. Most frequently, we see it covered at roughly 80% at our dental office with our patients.
Although you should be aware that it depends on your specific plan because we have seen it at 50% coverage as well. If that is the case, you can expect to pay about $215.26 instead.
Dental procedure code for billing: D2952
Alternatives
There are in fact three restorative options for replacing missing/damaged tooth structure after a root canal with complete caries removal. A cast post core is but one of those three replacement options.
Restorative options to replace damaged tooth structure after a root canal:
Cast post and core. This procedure requires two visits because it is made by the dental laboratory.
Prefabricated post and core. A one visit procedure that is done chairside using a titanium, stainless steel, or fiber post.
Core build up. A single visit procedure that is done chairside using a dual cure composite resin.
Essentially you can do a prefab post and core or core build up in lieu of the cast post. Typically which one will get chosen is up to your dentist's preference and what they think is best for your tooth condition.
Comparison of the different options
Cast post & core | Prefab post & core | Core build up | |
|---|---|---|---|
Number of appointments | 2 visits | 1 visit | 1 visit |
Strength | Very strong | Strong | Strong |
Aesthetics | Poor due to metal | Depends on post material | Metal-less |
Cost | $430.52 | $374.01 | $307.55 |
Essentially there are pros and cons to each of the restorative options. The cast post is the most expensive, strongest, but unfortunately has the poorest cosmetics.
Recent trends
Due to major advances in dental bonding technology, cast post and cores have slowly been falling out of favor. The current trend is doing more prefab posts and cores or even just core build ups. Since the bonding has improved so much, the post isn't as necessary anymore.
At our dental office in Long Island City, we've stopped doing cast post cores since 2019. After root canals, we mainly do core build ups. Once in a blue moon, we may do a prefab post but that is about it!
