What is a Root Canal Therapy?

root canal

Why do you need a root canal? Once the tooth becomes painful, there is two option typically.  The first option is to pull the tooth out that is causing the pain, and the second option would be doing a root canal.  A lot of people have a misconception of the fact that you only need a root canal if the tooth is aching, however, this is not true.  It is true for most people if there is a lot of cavity on the tooth, it becomes symptomatic, however for some, it remains to be asymptomatic causing no pain until the tooth becomes severely rotten to the point where the tooth becomes un-restorable. 

A root canal is a final resort to save the tooth.  If the tooth has just too much cavity to start with, because it would be impossible to buildup even after a crown procedure, the root canal therapy would not be indicated.  The general idea would be if you have not a too big cavity, you can get fillings, and if the cavity gets close to its pulp chamber, you would need a root canal to save the tooth.  However, if the cavity is too big, it may be even too late to even perform a root canal and the tooth needs to be extracted. 

Every tooth has dental pulp (pulp chamber) inside the tooth, which is a center of the tooth that contains nerves, blood vessels, and connective tissues.  Inside each root, there is a root canal, some cases more than one root canal, which contains nerve.  By performing root canal therapy (endodontic therapy), we are removing the nerve and making the tooth asymptomatic.  So you may wonder if the nerve within the tooth important?  The nerve provides a sensation for cold and heat but even without the presence of the nerve, the tooth can function for most of the time.  It just becomes asymptomatic.  It is important to maintain the tooth because with a missing tooth area, your back teeth may drift and your teeth alignment can be distorted. 

root canal access

Sometimes, even performing a root canal would be contra-indicated and you may be recommended to pull it out.  For example, if the tooth has too much cavity, and you cannot even put a crown or even after the crown procedure, if the post-op prognosis is too poor, it may be better to just pull it out.  Remember, if you cannot restore the tooth by building up the tooth, there is no point of even performing a root canal on the tooth.  If there is a root fracture, you cannot get the root canal and the tooth needs to be extracted.  If there is a severe bone loss due to periodontitis and the tooth has significant mobility, it is better to pull it out instead of a root canal.  It is important to ask your dentist about the prognosis of the root canal prior to the root canal procedure.

Signs that you may need a root canal:

  • Toothache
  • An abscess (ball on the gum tissue)
  • Discoloration (due to injury)
  • Too much sensitivity on a specific tooth, especially after a big filling
  • X-ray showing the presence of a cavity close to the nerve causing perforation into the pulp chamber

The Root Canal Procedure

Root canal therapy may require one or two visits to complete the whole procedure.  Depending on the level of infection, your dentist may prescribe you antibiotic prior to starting the procedure as the anesthesia may not work too well with infection.  Infection typically offsets the anesthesia.  On the first visit, your pulp chamber is accessed by drilling a small hole on the top surface of the tooth.  Then nerve canals in each root are removed.  On the second visit, they emptied nerve canals are filled with root canal filling materials.  Depending on the case, these two visits may be combined into a single visit.  Typically, incisors (front teeth) and premolars are a lot more simple compared to molars, and they may require a single visit. 

root canal procedure

During the root canal, an x-ray will be taken step by step to make sure treatment is going in the right direction.  Typically, you would need a x-ray before starting the treatment, one after measuring the working length (length of each nerve canals), one prior to cementing a gutta-percha (a filling material for root canals) for final check prior to finalizing the root canal, and one at the end of the whole root canal. 

To measure the working length of each root, x-ray and apex locator may be used, and once the working lengths are measured, nerves are removed with hand files and rotary files.  Then the empty root canal spaces are cemented with gutta-percha, filling material for root canals.  Once the root canal is completed, typically cotton pellet is put on the chamber and filled with temporary filling for easy access for follow up work.  Temporary fillings put on after each root canal instead of permanent filling because it is important to make sure you are not filling pain after the root canal.  Sometimes, some root canals are hidden and it is important to make sure the tooth is asymptomatic after the root canal to make sure all the canals are considered.  

Endodontist Referral

Most of the root canals can be performed by a general dentist, however, there are cases, where you would need to go to a specialist (Endodontist) for the root canals.  If there is a significant curvature on the root, you would be referred to an endodontist.  Or, during the root canal therapy, if a file fractures within the canal, you would need to go to an endodontist.  More curvature you have on the root, more possibility that file can fracture.  Sometimes, as you get older your nerve canal gets blocked by building up calcium within it.  If you have such calcified nerve canals, it would be out of scope for a general dentist to work on the root canal. 

Follow up after the root canal therapy

After the completion of a root canal therapy, your dentist may ask you to take antibiotics for a week.  Also, you will be wearing a temporary filling.  The temporary fillings are not bonded or strong enough to withstand significant pressure, so until next follow-up works are done be careful so that the remaining tooth structure on the tooth doesn’t fracture. 

Follow up work after root canal

Depending on the case, you may just end up getting a core-buildup or crown.  Sometimes, if there is not much tooth structure remaining, your dentist may propose a post-core prior to a crown.  In order for the crown to stay in, it requires at least some tooth structure to support the crown, and if there is not enough structure remaining, a little screw (post) is cemented into a root canal to support the crown. 

You can click on the following link to learn more about the crown procedure: https://www.midentalclinic.com/what-is-crown

You can click on the following link to learn more about the post-core procedure:


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