Core Build Up – Guide

Written & Reviewed by Dr David Chen

A core build up is a dental procedure that may involve pins or posts to restore lost tooth structure. It is considered an intermediate stage and not the final result because a permanent restoration typically follows after it.

core paste unopened

It’s purpose is to build back up the tooth into a shape that can accommodate a crown or a veneer. It is necessary because tooth decay will damage your tooth in ways that do not allow it to have a porcelain restoration over it.

Usually after removing the cavity, the tooth will have irregular holes, shapes, and undercuts. That is not conducive to placing a crown over it because it won’t fit. The core buildup will rebuild the tooth so that you can shape it in a way that can fit a crown over it.

The idea is akin to having two cups stack on top of each other. They must be trapezoidal and not have any undercuts for them to fit into one another. The same can be said for a crown being cemented over your tooth where it has to be a similar shape.

Well without further ado, we will expand further upon everything that you need or would want to know about dental core build ups.

When is it needed?

Build ups are required to rebuild lost tooth structure into an appropriate shape that permits a crown or veneer to be seated over the tooth. It is done after all of the tooth decay has been cleaned out. There are many situations which may necessitate having it done.

Situations where a core buildup may be required:

  • After a root canal. The root canal procedure will clean out all of the decay as well as remove the nerve of the tooth. The end result is a big hole in your tooth, which will require a core to restore it prior to placing a crown on top.
  • Before a crown. Teeth with medium to large sized decay will be better served with a crown rather than filling. It is especially true if more than 50% of the tooth structure is gone after excavating all of the decay. A core build up will restore the tooth to an appropriate shape that will allow a crown to be cemented over it.
  • Before a veneer. Prior to getting a veneer, all old fillings and cavities will need to be cleaned out. After that, you should rebuild the tooth with core material so that a veneer can fit over it.

We keep talking about using a core to restore the tooth into a shape that is conducive to placing a final restoration over it. That concept may be difficult for you to grasp which is why we will use an analogy.

Analogy: Before you place planks or tiles over your concrete floor, you should restore it to a smooth and flat surface. If you have bumps or holes in the concrete, the flooring you will be placing over it won’t do very well in the long run. The same can be said about placing crowns or veneers over a non-smooth and non-flat tooth!

Types of core buildups

The core material is a type of composite resin that is either self cure or dual cured. The great thing about it is that it can be used in different ways to suit the condition of the tooth.

  • With pins. Core buildups with pins were used a lot more frequently in the past but not so much anymore. You can think of the pins as mini-posts that are cemented into the tooth to provide additional retention.
  • With a post. This technique is still widely used today. It is an alternative to doing cast post and cores, which utilizes lab fabricated metal posts instead.
  • With a crown. Recent trends in bonding technology have advanced far enough that posts are not as needed for retention. The bonding is sufficient for holding the tooth together. A crown is still placed over it to provide better protection.
  • Without a crown. The build ups are typically not left on its own because it is not a permanent restoration. However if it is just for a short amount of time, the core material can be exposed to the oral environment.
  • Without a root canal. All root canaled teeth will at a minimum need a core but teeth without root canals can still get it as well. Teeth that need crowns or veneers that have old fillings or cavities will need new cores.

What to expect during the procedure

The entire procedure is very similar to how a tooth gets a filling placed. In fact, in our experience the core build up dental procedure is actually faster than doing a cavity filling. The main reason is that you can bulk fill the tooth and let it cure on its own. For fillings you need to cure each layer and that takes up a lot of time!

What happens during the procedure:

  1. Adminster local anesthesia.
  2. Excavate all old fillings and decay.
  3. Acid etch the tooth and rinse after 10-15 seconds.
  4. Apply bonding that is compatible with self-curing core material.
  5. Place the core material into the cavity in one go.
  6. Wait stated duration for the core to set.
  7. Cure it with the light just to ensure that it has fully hardened.
  8. Adjust and polish as needed.

Here is a video showing the procedure on a typodont model (fake tooth):

How long does it take

The entire procedure should take about 30 minutes or less. It usually takes a bit less time than doing a single tooth filling since you don’t have to cure the material in layers.

However you should be aware that while the procedure may be quick, most dentists will combine the treatment with the crown preparation. All together you should probably expect to spend about an hour at the dentist. The benefit of this is that you get to save a trip to the dentist by not having to come back for the crown appointment.

How long does it last?

As long as you don’t get recurrent decay, the core build up should theoretically last forever. Well not forever but long enough that you wouldn’t even remember when you got it done.

The reason why it’ll last that long is because a crown is typically covering over the tooth with the core to protect it. That means it won’t be exposed to the oral environment at all. The porcelain from the crown will be taking the brunt of the impact when you’re eating and chewing.

There is one exception and that is if you get the core without a crown. In that case, it may not last as long because the core material is designed to be similar in hardness to the dentin. The dentin hardness is significantly less than the enamel hardness. In other words it will wear away faster if you’re eating and chewing on it directly.

Core build up vs Dental composite

Both core material and composites are made of a dental resin and they’re used to restore lost tooth structure. However there are differences between them.

  • Wear resistance. Composites are made to be resistant to wear from chewing and eating. They’re meant to be similar to and to replace the enamel. Core on the other hand is made to mimic the toughness of dentin.
  • How they set. Core build up material are always self cure but some of them have the option to be light cured as well. Composites are mostly light cured with very few having self cure properties.
  • Type of restoration. Dental composites are meant to be permanent restorations while core material were meant to be an intermediate product.

Usually if you’re getting a core buildup instead of a composite, it means that there will be another treatment or step afterwards. If you’re getting a composite then it probably means that is the final step.


The average cost for a core build up in the US is about $307.55 according to the ADA 2022 survey of dental fees.

  • The 10th percentile was $230.
  • The 95th percentile was $412.

The actual numbers may vary depending on the cost of living where you’re located. These numbers were based on a survey of dental offices which responded. It is only meant to give you a rough idea of what to expect.


Core build up procedures are used to restore a tooth back to a state where it is fit to have a permanent restoration placed over it. It is necessary because cavities can ravage the tooth to a state which makes it unfit for crown.

The most common reason to get it is after a root canal but there are plenty of other scenarios which require it as well. Just understand that the procedure is not the final result because it is an intermediary step. That means you should expect to undergo an additional procedure after getting it! Your journey to the dentist has not ended even after completing this treatment.

This article was written by Dr David Chen. If you need this procedure done and you’re in the NYC area, please check out our dental practice.


1311 Jackson Ave
Long Island City, NY 11101

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