The crown broke off with a tooth in it – What should I do?

crown broke with a tooth in it

Root-canal treatment followed by a crown is one the most common dental treatment given to the patients worldwide with a success rate of 90% after 9 years. However, root-canal treated teeth are fragile and more prone to breakage than healthy teeth. You can run into an unpredictable crisis if you have a crown on your tooth. In this blog, I will discuss ways to manage if your crown breaks/ broke off with a tooth in it.

Let’s first understand the reasons that can lead to crown breaking off with a tooth in it;

7 factors resulting in crown breaking off with a tooth in it

If you come to the dental office complaining that your crown broke off with a tooth in it; the dentist will look for or ask about the following to track down the reason for it:

Reduced tooth structure in root canal-treated tooth

The reduced tooth structure resulting from tooth cutting in root canal-treated tooth to make room for the crown, predisposes it to fracture. 

Premolar teeth are smaller in size than molars and tooth cutting for a crown placement further reduces their size. For this reason, fracture most commonly occurs in the root canal-treated upper premolars.

Also, the tooth whose tooth structure is destroyed at the beginning of the treatment has a greater chance of fracture. To compensate for their lost tooth structure, a post and core are placed in the tooth to strengthen it. Nonetheless, occasionally the post comes out with the crown.  

Propagation of micro-cracks in a tooth

If the tooth is already cracked at the time of the root canal, the crack may propagate over time and cause tooth fracture. Micro-cracks in the teeth often go undetected and require special equipment to diagnose them. 

an Injury to the front crowned tooth

The crown breaks with a tooth due to a

Sports (such as a fist fight), or fall injuries causes direct impact on the front tooth, leading to fracture of the tooth. People with incisor crown often comes to our practice saying, their crown broke off with a tooth in it.

It is important to know that when the collision occurs, the fracture occurs at the weakest point. In a crowned tooth, the structurally reduced tooth takes the greatest impact and fractures.    

habit of teeth grinding 

The habit of grinding teeth places horizontally directed forces on the teeth that are detrimental for the crowned tooth. These destructive forces lasting several hours daily, especially at night and during stress can result in tooth fracture.

Chewing on hard foods

Chewing on hard foods can also harm the crowned tooth. Also, habits such as cracking a nut or sucking on ice cubes exert heavy pressure on the teeth leading to fracture. 

Secondary or recurrent decay at the crown margins

The marginal fit of the crown is a prerequisite for its success. The crown with poor marginal fit leads to the dissolution of the bonding material and encourages plaque deposition, followed by tooth decay.

The secondary decay weakens the tooth and, if neglected for a long time, breaks the tooth at the gum line.

root canal treated tooth with a post

Posts are inserted in the root canal-treated teeth to strengthen them, where more than half of the tooth is lost due to tooth decay. Root canal-treated teeth with posts are more prone to snap than the ones without posts.

According to a research, 62% of the extracted root-canal treated teeth that suffered root fracture had posts.

Dentists advise different post materials based on the patient’s case and affordability. The earlier metal posts cause more root fractures than the recent fiber-reinforced posts. For the longevity of tooth, the hardness of the post material should be compatible with the tooth hardness so they can work in harmony while chewing.

The teeth bend a little during chewing, and an incompatibility between the two material causes unnecessary pressure on the tooth, leading to root fracture years after the post-placement. 

crown broke off with a tooth in it
The graph shows the pattern of tooth breakage in root canal treated teeth. The bar length represents the percentage of the particular factor. First molar is the 6th tooth from the center on each side.

What do you do if your crown falls out?

The management of a crown breaking out with a tooth in it will depend on the damaged incurred to you. 

If the crown breaks off after a fist fight, fall, sports injury, or as a result of direct impact on the front tooth, you may experience some bleeding if the gums or lips have been injured. Report immedietly to the emergency room or emergency dentist in such a scenario.   

If the injured tooth is root canal treated, you may not experience any pain or discomfort. However, a crown placed on a vital tooth may cause pain or sensitivity after the injury. If the injury is not associated with any bleeding, then this is not a dental emergency. Stay at home and follow the instruction given below. 

Also, the crown of a root-treated tooth breaks while chewing hard food or grinding teeth. You may not experience pain as the root canal-crowned tooth is already dead. 

Don’t panic. Just calm down and take a couple of deep breaths. Follow the instructions given below:

  • Rinse your mouth with water to remove any tooth particles. 
  • If the tooth hurts, take over-the-counter pain medication.  
  • Keep the tooth in a plastic bag and take it to your dentist at your appointment. 
  • Don’t touch that site unnecessarily with your tongue, as the ragged tooth edges can damage your tongue. Place a candle wax or sugarless gum over the tooth to prevent an injury to the tongue and cheek. 
  • Book an appointment with your dentist as soon as you can. 

How do a crown look like when it breaks with a tooth inside it?

First, you need to confirm that it’s a crown that broke off with a tooth in it. You will see the following things when you look in the mirror:

  • The site of the tooth from where the crown has come off will look empty, with a portion of the remaining tooth.
  • The crown that falls out without the tooth is empty from inside. However, the crown broke off with a tooth contains the part of the broken tooth. 
  • On placing your finger on the tooth stump, you may feel sharp edges of the tooth. 
  • In some cases, the crown breaks off with the tooth due to decay underneath the crown which appears as the root canal turning black or tooth blackening at the gum line. 

Can a dental crown be reattached? 

In most cases, the crowns fall out without a tooth because of the failure of cement that bonds crown to the tooth. Such a crown can be placed back on the tooth. However, if the patient complains that his crown broke off with a tooth in it, the crown can not be reattached to the tooth.  

What will the dentist do about if a crown breaks with a tooth?

Treating a broken tooth depends on where the breakage has occured in the mouth. Mostly the tooth breaks away with a crown from the gum line. In such cases, the patient reports to the dental office saying, my crown broke off at the gum line. 

The decision to extract or save the tooth banks on the amount of tooth structure left after the injury. A 1.5- 2mm of healthy tooth structure is required to keep it and cover it with a crown. 

In patients with insufficient tooth structure left above the gums, but with long and healthy roots, crown lengthening procedures or orthodontic extrusion of teeth can be anticipated. 

A crown lengthening procedure involves the removal of gums to expose the tooth’s root in the mouth so a crown can be placed. In the orthodontic extrusion of teeth, an appliance is used to move the tooth out a few millimeters in the mouth to cover it with a crown.  

If the dentist decides to extract the tooth, a partial denture, bridge, or dental implant can be a suitable replacement.

How to prevent crown and tooth breakage?

Healthy teeth have a blood supply, and fluid running through the dentin tubules (dentin has tiny tubes or channels), which makes them resilient. The root canal-treated teeth are devoid of fluid, which makes them fragile and more prone to breakage. 

The following measures can prevent crown breakage from occurring.

  • Avoid biting on hard food, such as cracking a nut or biting on nails. 
  • Wearing a night guard prevents teeth from destructive teeth grinding forces.
  • Wear a face mask or mouthpiece during sports if you have crooked teeth, rabbit teeth, or have suffered an injury on the front teeth in the past. 


Patient’s complaint that his/her crown broke off with a tooth in it is an unusual outcome in a root-canal treated tooth. Most of you are unaware of how to deal with this situation, especially, if it happens on the weekend or at night when you can’t get hold of the dental office asap.

It’s not an emergency and you don’t need to worry about it unless you incur bleeding or trauma to the head or neck region.

If any such thing happens to you, compose yourself first. Next, look in the mirror to ensure the missing tooth in the mouth is the crown that has broken off with a tooth. Keep the crown in a zip lock bag and book your appointment with your dentist. 

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