ROOT CANAL (ENDODONTIC) THERAPY

Whenever the nerve/pulp of the tooth has become irreversibly affected to the point where it is either dying  or dead, your tooth will require root canal therapy.  The only alternative to root canal therapy is tooth extraction in that both therapies remove the bacteria associated with a dead nerve.

Generally, the reason that your tooth will require root canal therapy is directly or indirectly related to bacteria associated with tooth decay.  Whenever untreated tooth decay allows the bacteria to affect the nerve, the nerve becomes inflamed; a condition we refer to as pulpitis.  In the event, that nerve pulpitis continues, pulp death is the eventual outcome.    Treatments are designed to reduce the overall possibility of nerve death.  In the event that the nerve dies after treatment, consider that it faced an even higher possibility of nerve death without treatment, however, it just happened sooner.

How do we know (diagnose) that your tooth will require root canal therapy?  Here are some of the signs and symptoms:

• Throbbing pain, either intermittent or constant.
• Pain associated with temperature (hot/cold) changes where the pain does not go away immediately (within 5 to 10 seconds) after withdrawal of the temperature stimulus.
• Pain associated with biting.  This occurs when pressure is put on the tooth and pain increases as pressure increases.
• Pain when putting the teeth together or simply by putting any pressure on the tooth.
• Radiographic diagnosis.  This is where we see evidence of acute or chronic infection associated with the tip of the root.
• Pulp test diagnosis.  This is where an electrical stimulus is applied to your tooth and it fails to respond to the maximum output.
• Pulp/nerve exposure during a restorative treatment.  Usually, you will be informed of this possibility prior to treatment.
• Pulp/nerve exposure as a result of tooth fracture or trauma, e.g. rugby, falls, bicycle accidents, etc.

Once we have made the diagnosis, we can then begin therapy, however, it is imperative to note that not all signs and symptoms described above are a result of a tooth requiring root canal therapy.  There are other types of conditions that can mimic root canal signs and symptoms.  For that reason, it is important for the dentist to rule out other possibilities, such as TMD, sinusitis, neuralgias, etc.  It is not uncommon to have vague symptoms which preclude an easy diagnosis.  In that case, it may be prudent to wait a while, taking whatever pain measures may be necessary until the quality of pain changes to allow a definitive diagnosis.  It may require a referral to a root canal specialist (endodontist).

A root canal treatment is performed by entering the nerve through the biting surface of the tooth.   Once the nerve is entered and cleaned out, all the roots and their canals are identified, filed, cleaned out and then filled.  You can see some of the technology used in modern root canal therapy by going to the page on endodontic technology.  Once the root canal procedure is completed, the access hole is either sealed up or the tooth is then ready for final treatments such as a crown.  It is vital that you do not neglect to complete treatment on your newly root canalled tooth.  In the event that you delay and the root canal filling becomes exposed to bacteria for as little as three days, it may become necessary to re-treat your root canal treatment.  

As with all treatments in medicine or dentistry, the treatment outcome and prognosis for that tooth is not 100%.  The first thing to note is that root canal therapy is approximately 98% statistically effective the first time it is performed.  The reasons that initial root canal therapies might fail might include:

• Canals which were not discovered.
• Canals which could not be negotiated.
• Complex root canal anatomy.  Examples of this are severe root curvatures or where the canals split into multiple canals and cannot be negotiated by the single file.
• Breakage of endodontic files in the root canal.

For these reasons, we cannot guarantee that your root canal treatments will work.  We cannot overcome statistics but we can at least try to reduce them.  In our office, we do not re-use our rotary endodontic files.  After use on you, they are disposed.  This has greatly decreased the number of broken instruments in the canals.  In the event that a root canal treatment does not work, there are several options that may be pursued.  These options might include simple re-treatment and/or referral to a root canal specialist (endodontist).  Re-treatment of a failed root canalled tooth will result in some success, however, that statistic will never become 100%.  What happens to the very small number of teeth that are not amenable to our best efforts?  They are usually extracted.  This is usually a 'bitter pill' to swallow, especially when we have thrown all our available treatment options towards your tooth, incurring significant time and expense on your part, only to end up with failure. 

Once a tooth has been root canal treated, you now need to know some facts on the long term prognosis of these teeth.  Following are some of the problems that might be associated with root canalled teeth:

• Root canal failure may occur if recurrent decay allows bacteria to enter the root canal filling.
• Loss of the tooth may occur in the event of a root fracture.  Since a root canal treated tooth is weaker, overloading may cause mechanical fracture of the tooth.
• Porcelain fracture or failure of the restoration may occur due to the access hole which was drilled through the crown.

Not all teeth are equally susceptible to failure from root fracture.  This has a lot to do with their remaining tooth structure, their position in the mouth and the forces they are subjected to.  This is particularly significant when  a root canalled tooth is used as a fixed bridge abutment.  Simply put, when a root canalled tooth is used to 'anchor' one end of a bridge, the fact that more force is applied to each of the anchors in any bridge, means that the tooth will have a reduced prognosis and will be more likely to fail.  In this case, tooth failure means bridge failure.  For this reason, we will not advise using a root canal treated tooth where a bridge may be considered to replace missing teeth.  Usually, a removable denture or implants will be a much better option.  Another situation where the incidence of root fracture is increased is where parafunction (grinding and clenching) is involved.  In this case, the excessive forces make the root canalled tooth more susceptible to fracture and therefore extraction.

Whenever a tooth has just been root canal treated, it is also worth noting that there is a statistical possibility of post-op pain and swelling.  This can occur even if the therapy will be successful. In the event that there is some post-operative discomfort, we will recommend taking some form of anti-inflammatory OTC (over the counter) medication.  In the event that the swelling becomes significant, we may then prescribe antibiotics.  Note that we will try to hold off on the antibiotics unless it appears to be necessary or there are other significant health concerns.

Root canal therapy is a procedure commonly performed in our office.  In the event that we feel you are better served by visiting a root canal specialist, we will not hesitate to recommend a referral.  Situations where we will suggest a referral may include:

• Complex failure.
• Failure within a complex prosthesis, i.e. a bridge or crown.
• Situations where we feel the skills of a root canal specialist are required.
• Procedures required which are not available in our office.

Please be aware that you may also request to see a root canal specialist for any root treatment.   We will  be happy to arrange this referral for you.

Please let us know if you have any further questions on this subject.  Remember, we will try to avoid root canal therapy at all costs.  Whenever we suggest root canal therapy, we do not believe it is an option unless we are considering extraction.