Root canal therapy is the treatment of a tooth with diseased or infected nerve. In the past, such a tooth had to be removed. With advancement in dentistry, many of these teeth can now be treated successfully. The dentists at Venier Dental Group will make every effort to save your tooth without causing you any discomfort. We want to help you preserve your natural teeth for good. In some cases a root canal cannot be done in our office in which case we would refer you to an endodontist to have your root canal completed there.
The first step of a root canal procedure is to identify the tooth with the problem. It may not be as simple as it sounds, since sometimes the pain is so strong that it radiates to adjacent teeth, making it difficult to understand where the source of the pain is. In some cases, an x-ray might be needed to provide evidence of a tooth abscess at the end of the infected tooth. Before making the decision to proceed with root canal treatment, the dentist must make sure that the pulp/nerve is not alive. If the tooth does not respond to hot or cold stimuli, it is an indication that the pulp is dead.
Sometimes the dentists use a device called electric pulp tester to identify the condition of the pulp. The results of these tests will indicate whether or not an endodontic procedure is necessary.
If there is inflammation and swelling, the dentist may prescribe an antibiotic and/or anti-inflammatory medicine for some days before starting the root canal procedure. The purpose is to control the infection and to ease the swelling which can make the anesthetic less effective. If the condition is painful, the patient will have to take an over the counter or prescription analgesic to relieve the tooth pain until the procedure. The next step in the procedure is to take an x-ray to check the shape of the root canals and determine if there are any signs of infection in the surrounding bone.
In order to perform the root canal treatment, the dentist must gain access to the infected pulp area inside the tooth. First, the dentist will remove any tooth decay from the crown of the tooth. Then, an opening is drilled through the tooth crown into the pulp chamber, over the position where the dentist expects to find the nerve. On the back teeth the access hole is made on the chewing surface of the tooth, while in front teeth the hole is made on the lingual side of the tooth, to keep it off sight. Opening the dental pulp chamber relieves the pressure inside the tooth and can offer significant pain relief.
After the canals have been measured, the dentist or endodontist will start the cleaning procedure that involves the removal of bacteria, nerve and dead tissue debris from the interior of the tooth. First, any remaining pulp tissues are removed from the pulp chamber with the use of a slow speed hand piece (drill). After the pulp chamber is cleaned the dentist inserts endodontic files into the root canal to remove the nerve from inside the canal. When the nerve is removed, the root canal has to be slightly enlarged, shaped and smoothed for the correct application of the filling material in the next step.
The dentist or endodontist will start with a very thin file followed by progressively larger diameter files until the entire mass of the nerve is removed and the sides of the root canals are made smooth and clean.
After each pass with the endodontic files, the pulp chamber and the root canals are irrigated with a solution in order to wash out bacteria, dead tissue and debris, and to sterilize and chemically neutralize any dead tissue that may be missed by the files. Instead of bleach solution, some dentists use a solution of chlorhexidine.
Cleaning the root canals is the most critical part of the dental root canal procedure. The dentist has to be careful to clean all the infected tissue, not miss any root canal or branch of a canal and use the files exactly up to the measured length of the root canal, no less – no more.
The procedure is usually performed by the dentist by hand, moving up and down and twisting the endodontic file inside the root canal, in order to scrape and scrub the sides of the canal. Other options include the attachment of the file to a low speed hand piece or using ultrasonic equipment.
The cleaning phase of a root canal procedure might need more than one appointment, especially in cases when the dentist suspects that the root canals are branched in a way that infected tissue and bacteria might be left in areas that the dentist cannot see or the files can’t reach. In these cases, the dentist will put antimicrobial medication in the pulp and canal area to kill any remaining bacteria and will use a temporary filling to protect the tooth until the next visit.
The dentist may decide to leave the tooth open for a few days to allow drainage of a periapical abscess and prescribe an antibiotic to stop the infection. If the infection is not controlled until the next appointment, the process is repeated.
For a root canal treatment to be successful, the tooth should never be permanently filled and sealed before it is completely free of active infection. Some dentists wait for a week or more after the root canal procedure before they proceed to the filling of the tooth but this is not always necessary. If a dentist is sure that the infection is sustained and the tooth is completely cleared, there is no problem in finishing the root canal treatment in one single appointment.
When the dentist decides that it is safe, he will dry the interior of the root canals with paper points and start to fill them with a permanent root canal filling material. The material used for the filling is often a biocompatible rubber-like material called “gutta percha” in combination with an antibacterial cement (sealer).
Gutta percha is a pink colored root canal filling material shaped in cones that come in different diameters in order to match the files which are used to clean out the inside of the tooth and fit exactly to each root canal. The creamy sealer is inserted first in the root canal or it is applied to the cone's surface. Then the dentist inserts the gutta percha cone carefully into the canal exactly up to the tip of the root. This is the phase where the measuring of root canal’s length and diameter, done in previous phases comes to use.
Additional gutta percha cones may be placed besides the first one to fill the entire root canal. The dentist uses the gutta percha cones to put pressure on the soft creamy cement so that it is forced against the canal’s walls and into every tiny branch of the canal.
The purpose of the process is to seal completely the canal from its environment, to prevent bacteria from entering the tooth in the future. Sometimes the gutta percha is warmed (or applied with a thermal ‘gun’) to better adapt to the precise shape of the interior of the tooth.
If the tooth has suffered significant damage from tooth decay and it is unable to support a crown, the dentist will place a metal post in the pulp chamber to provide structural support for the crown restoration.
As soon as the root canals are filled, the opening at the crown of the tooth can be sealed with a permanent filling but usually a temporary filling or crown is used until a permanent restoration may be made.
After the tooth is sealed, the root canal treatment is considered completed. The crown of the tooth should then be restored with a permanent filling or crown within a relatively short time.
After the completion of the root canal procedure only the interior of the tooth is treated. The external surface of the crown has to be restored for the tooth to get back its form and functionality.
The final tooth restoration should not be postponed for a long time (no more than a month) because it increases the risks of a re-contamination of the tooth. Another problem is that the tooth remains weak until restored, and it will fracture easily if pressured.
Depending on the general condition of the tooth and the amount of tooth structure lost, the dentist will decide if a permanent composite filling is enough or a crown should be placed. Endodontically treated teeth often become brittle with time after treatment. Crowning the tooth is usually safer, especially if a molar is involved. A crown is cemented on the tooth to strengthen its structure and improve appearance, by a general dentist or a prosthodontist.
After a properly performed root canal procedure and restoration, a treated tooth can function normally for a lifetime.