Root Canal Therapy Procedure Explained : Part 2

Thursday, January 24, 2008

The following is the final 2 steps to a root canal therapy procedure. To learn more about the first 3 steps of a root canal therapy procedure, please refer to Root Canal Therapy Procedure Explained : Part 1.

Step 4: Filling the Inside of the Tooth
After the tooth is sterile and completely free of infection, debris, and bacteria, the dentist or endodontist needs to fill the inside of the tooth to seal it off to minimize the chance of any more bacteria getting inside the tooth and causing the infection to re-occur. The inside of the tooth is filled with Gutta-percha and a root canal cement. Gutta-percha look just like paper points, except they are reddish in color and made from the Gutta-percha trees found in South East Asia. The reason why this material is used is because its chemical and physical properties make it compatible with the tooth structure. Basically, the body won't reject this material. Gutta-percha is also used because it will show well on an x-ray. The dentist or endodontist will also take an x-ray before the cement is added to make sure the Gutta-percha is placed so that it touches the inside of the tip of the root. If the tooth is not completely filled, there is an increased chance of the infection returning.

The image to the left is an x-ray of the lower right first molar after a root canal treatment has been completed. You can see three teeth on the x-ray. The one in the middle is the root canaled tooth. There are two roots that are visible on the x-ray. The top white portion of the tooth is a filling placed on the crown, (hard outer layer), of the tooth. The center white portion is where the pulp was removed and Gutta-percha and cement were placed. The two white lines that show in the roots are the Gutta-percha points inside each root chamber. If you look at the tooth on the right, you can see the nerve in the center of the tooth and as it moves down into the root. It looks like a black line on an x-ray. (The more dense an object or material is, the whiter it will appear on an x-ray.) To learn more about the layers of the teeth and the function they serve, please refer to my tooth anatomy article.


Step 5: Temporary Filling
When the inside of the tooth has been sealed with Gutta-percha and root canal cement, the dentist or Endodontist will place a temporary filling in the tooth to close the hole that was drilled into the tooth to gain access to the inside of the tooth. At this time, the root canal therapy has now been completed. The patient is then scheduled with their dentist within a few weeks to have a permanent restoration placed on the tooth. Most often, a crown is recommended.

A temporary restoration is just that – a temporary restoration. The material that is used is not durable enough to withstand daily wear and tear for long periods of time. If the temporary filling material becomes loose, falls out altogether, or simply begins to chip away, it needs to be replaced or a permanent restoration needs to be placed. If the filling material is not replaced, there is an increased chance of bacteria getting back into the fragile center of the tooth and the tooth may decay or re-abscess. Thus, causing the root canal therapy to fail.


Many times, the root canal therapy procedure can be completed in one visit. However, the dentist or endodontist may decide to complete the procedure in more than one visit. This is normal and nothing to be concerned about. If the dentist or endodontist schedules more than one visit, he or she will temporarily seal the tooth off, usually with a cotton pellet, and instructions given on what to expect next. When you return, the dentist or endodontist will repeat step 3 until he or she is confident that the inside of the tooth is sterile, free from debris, infection, bacteria, and ready to be filled.


After the root canal treatment is completed, the tooth is a non-vital tooth. Meaning that the tooth is considered dead. (In dentistry, there are two types of teeth – vital and non-vital. Vital means the tooth is considered alive and will react to stimuli, such as hot and cold, pressure, and pain. Non-vital means the tooth will no longer respond to hot and cold, pressure, or pain.) The pulp, often referred to as the nerve, is full of blood vessels which supply the tooth with blood and nutrients. When a root canal procedure is performed, the pulp is removed from the tooth. The nerve is gone. There is no response to pressure, hot and cold, or pain from the tooth itself. The patient will be able to feel pressure, hot and cold, or pain from the ligaments and tissue surrounding the tooth as they did before the root canal procedure was performed, but the tooth itself is non-vital.