Why is root canal treatment not a prerequisite for a dental crown?

gum graft healing stages
Although root canal treatment and dental crowns are two separate procedures, they have the same purpose: protecting and keeping the tooth as long as possible.
Root canal therapy involves treating the inside of the tooth when the pulp is infected. While the crown restores the visible part of the tooth when it is damaged.
Often, crown placement requires root canal treatment when the tooth's nerve is affected or threatened.
Sometimes, depending on the situation, the tooth needs only one of the two procedures, as the principle of any dental treatment is to preserve the maximum amount of healthy tissue.
Find out in this article why it is important to preserve the tooth's nerve and when root canal treatment is a prerequisite for the crowning procedure.

The role of the dental crown

The dental crown is a permanent restoration that covers the visible part of the tooth. It is one of the most common procedures in dentistry.

It restores the form and function of the tooth altered by a carious process or a trauma.

It also restores the aesthetics, especially in the front teeth. Although veneers are the best option in this regard, they are not a viable choice for severe and deep stains. In this case, dental crowns are a good alternative.
They can also correct a slight malposition, allowing you to avoid wearing braces.

Dental crowns insulate the pulp of living teeth from thermal shock thanks to their physical properties. They cover our teeth and protect the nerves from mouth bacteria, which could cause an infection.

For non-vital teeth (with root canal treatment), it strengthens the tooth structure and protects it from the stresses of chewing. Teeth with endodontic treatment are more fragile and, therefore, more susceptible to fracture. This is why crowning a non-vital tooth is a common procedure.

So, with or without root canal treatment, the dental crown protects the tooth and increases its longevity.

The role of root canal treatment

Root canal treatment consists of emptying, cleaning, and filling the tooth canals. It replaces the diseased nerves with a biocompatible material that fills the space inside the tooth and prevents bacteria from infiltrating the deep tissues around the root tip.

After filling the canals, different options are available to restore the tooth shape. Depending on the damage extent, it can be a simple filling, a crown alone, or combined with a post for better hold, when more than half of the tooth is injured.

What happens to the tooth during the crowning procedure?

During the crowning procedure, the tooth undergoes a lot of trauma. To understand the process, you need to know that dentin, the second tooth layer underneath the enamel, contains many canals called tubules. A 1mm section of dentin uncovers 2,000 to 50,000 tubules that lead directly to the pulp. Therefore, the tooth with exposed dentin is more susceptible to bacteria and sensitivity.

During the procedure, your dentist must make room for the crown. He will trim the tooth, removing the enamel and leaving a layer of dentin. The thinner it is, the more threatened the pulp is.

In addition, to prepare the tooth, your dentist works with instruments that rotate at very high speed (150,000 rpm to 200,000 rpm). This will expose the tooth to high temperatures and vibrations that can damage the nerves. For this reason, it is not uncommon to experience some discomfort after the procedure, which in most cases is temporary and reversible.

Crowning the tooth is definitely a high-risk procedure for the pulp. But is this reason enough to devitalize the tooth?

Why is root canal treatment not a prerequisite for crowning the tooth?

The nerves of a healthy, living tooth must be preserved, as is the case with a tooth that will receive a crown.

Saving the pulp means preserving the natural defense potential of the tooth. Indeed, the pulp contains the nerves and blood vessels that feed and produce dentin throughout the tooth's life. In response to bacterial aggression, it will form a barrier called reactionary dentin, which prevents the bacteria from approaching the pulp.

In addition, a vital tooth is more resistant to chewing forces than a tooth with a root canal.

During the crowning procedure, your dentist takes various measures to limit damage to the tooth. He works under constant water irrigation and reduces the pressure of the rotating instrument to avoid overheating.

At the end of the preparation, he will place a temporary crown to increase your comfort and protect the tooth from bacteria and mechanical stress.

Usually, the reactions of a healthy pulp after the crowning procedure are reversible and temporary, decreasing as healing progresses.

A study published in the Journal of Dentistry found that the success rate of crowned teeth does not depend on pulp vitality. Vital and non-vital crowned teeth have the same success rate. Moreover, a large percentage of vital teeth (83%) will not show any symptoms over the next 25 years.

Irreversibly damaged pulp following a crown placement is not the result of the procedure itself. A healthy tooth has the potential to repair itself. But, if the tooth pulp was already injured, placing the crown would only push the tooth towards an inevitable end.

When does a crowned tooth need root canal treatment?

In some situations, the tooth must undergo root canal treatment before receiving a crown. It is especially the case for:

  • Irreversible pulp inflammation: As soon as the decay reaches the pulp, the pulp defends itself by triggering inflammation. At an advanced stage, the decay causes damage that the pulp cannot repair. Symptoms include persistent, intense, and throbbing pain. In this case, root canal treatment is essential to disinfect the tooth and ensure a successful crowning procedure.

  • Pulpal necrosis: If left untreated, the inflamed pulp may eventually die. The pain will subside, but this does not mean that the tooth is safe. Inflammation products can accumulate around the root tip and cause an abscess.

  • Thin dentin layer: When there is not enough dentin to protect the pulp from the outside, bacteria can easily reach it through the tubules. The risk of infection is thus high.

  • Severe gum disease that has affected the pulp.

  • Deep dental crack.