Cracked tooth after a root canal

cracked teeth

What is root canal

Inside the tooth is a soft tissue called the pulp. It contains blood vessels and nerves that allow the tooth to develop and defend itself.
When the pulp is penetrated by bacteria due to cavities or cracks, it becomes infected and must be removed. Your dentist may tell you that you will need root canal or endodontic treatment to empty and disinfect the inside of the tooth.

What is a cracked tooth

Cracked tooth is a lesion which can be the result of a shock, teeth grinding also known as bruxism or due to aging. It can be visible or felt by your tongue if the fracture is thick, but most often it is invisible and requires dental examination by your dentist.
This problem can affect people of all ages, it is the third cause of tooth loss and can be associated with severe pain during chewing and sensitivity to cold or heat.

The most common fractures after a root canal treatment

After root canal treatment, different types of fractures can occur, especially the cracked tooth syndrome in which the fracture begins in the crown and goes towards the root. Pain is felt when chewing hard foods. The pain comes from the gum because the fractured tooth irritates the gum.
The treatment of this type of fracture depends on its extent and severity. If it is limited to the crown, the tooth can be preserved, while if the root is reached, there is a high chance that the treatment will fail, because it will weaken the tooth even more, leading to worsening or the appearance of new cracks.

In addition to cracked tooth syndrome, other types of cracks may occur :

Fractured cusp:

It is a crack which arises from the chewing surface of the tooth and can end in the crown or the root. It is due to bulky restoration and cavities which can weaken the tooth and can even lead to total fracture. If the crack is not deep, your dentist can preserve your tooth, he will consider a restoration that will aim to protect it.

Split tooth:

split tooth
It is a complete crack which goes from the crown and ends in the root. The crack separates the tooth into two fragments. Pain is reported during chewing, sometimes associated with a periodontal abscess. The tooth can be saved by removing one of the two fragments.

Vertical root fracture:

vertical root fracture
It occurs if the root is weakened too much by endodontic instruments. It is a fracture which begins in the root in a coronary direction. It can cause periodontal complications by creating a door to bacteria towards the deep periodontium (the space which surrounds the root). Pain is marked during chewing, sometimes associated with dental mobility and signs of infection.
The treatment options are limited, the extractions are carried out most of the time, sometimes it is possible to save a part of the tooth by separating its two roots.

Why our teeth is more susceptible to fracture after root canal treatment

If we compare a devitalized tooth to a branch of dead wood, the two are emptied of their internal content, for the teeth it is the blood while the wood is the sap. The devitalized tooth or dead wood looks solid, but they can break at any time. The major risk of most devitalized teeth is therefore fracture. Risks become even greater if the treatment is repeated.

It is therefore obvious that the tooth which has an endodontic treatment is more sensitive than a normal tooth, it is due to the absence of the pulp which supports the tooth during all its life, and the loss of dental substance due to the use of sharp instruments to empty and thicken dental canals. There is a high risk that this fracture is deep under the gum causing pain during chewing, in this case, the tooth must often be extracted. Otherwise, if the fracture is limited to the crown, the tooth can be preserved by protecting it with a good restoration.
cracked teeth

Complications of a cracked tooth

After a root canal, the complications mainly concern the periodontium, which is the tissue that surrounds the tooth. The fracture will present a gateway for bacteria to the structures surrounding the tooth leading to periodontal infection. Among the signs of periodontal involvement, redness, swelling and bleeding of the gum and sometimes an abscess can appear on it.

Signs of infection on general health may appear: Fever, cervical lymphadenopathy which is swelling of the lymph nodes in the neck, wheezing, appearance of an abscess and loss of appetite due to exacerbated pain during meals.

Solution and prevention

After root canal, tooth is more likely to be fractured. If the lesion only concerns the crown, the tooth can be saved, but if the fracture has reached the root, treatment depends on its depth:
The fracture concerns only the end of the root without displacement or mobility: No immediate treatment is necessary while waiting for natural healing, but monitoring is essential in the days and weeks following the fracture.

High root fractures (located near the dental crown) require crown lengthening. It is the reduction of the gum and bone to expose more of the natural tooth in order to eliminate cracks and restore the tooth.

On the other hand, root fractures at mid-height of the root or over its entire length (vertical fracture) make tooth conservation impossible. The tooth will be extracted and replaced by an implant or bridge.

It is impossible to stop dental fractures, however, it is possible to prevent it. The only effective way to deal with this problem is to fix a crown which will protect the tooth from cracking.
I advise you as the same to:

  • Optimize your dental hygiene by brushing at least twice a day, daily floss and visit your dentist every 6 months. Healthy teeth are less likely to be fractured.
  • Wear a mouthguard: If you grind your teeth at night, have a night-guard made to protect your teeth. If you play sports, wear a custom-made mouthguard.
  • Avoid biting or chewing on hard objects, especially on the area where the root canal treatment is carried out.