Dental Posts

Once root canal treatment has been performed then the tooth must be restored. Root canals are usually performed on teeth that are quite broken down and therefore must be built up to have enough tooth structure available to hold onto a crown. In order to retain the core buildup, many times a post must be placed inside the root canal. This is done by removing a portion of the root canal filling material (the part closest to the tip of the root is left to seal the end) and drilling out the proper size to accept the post (no need to worry about the drilling – remember there is no nerve in a root canal tooth). Then, the dentist chooses one of two types – a cast post and core or a prefabricated post. The cast post and core has advantages in that the core buildup is made as one piece with the post so there is no way for the two to separate. A disadvantage is that it must be fabricated outside of the mouth and therefore cannot be cemented on the same day, however, other provisions must be made to build up the tooth. Some prefabricated posts are metal and some of the newer ones are made of carbon fiber composite. The newer carbon fiber ones have a little bit of give to them and they look promising on possibly reducing root fractures in teeth with posts.

Root Canal Retreatment

A root canal is not something that we normal humans would look forward to. How about the poor people who have to have a root canal retreated? It’s a common perception that once a root canal has been done, there will never have to be anything else to do for that tooth. While that is true with most root canals, there is an occasional one that is not successful.

Root Canal Tooth Needing Retreatment

The most common reason is not being able to get a good seal on the root. Any leakage around the root canal filling material can allow bacteria to filter in. Since there are no blood vessels in the area (those were removed by the root canal process), there will be no way to get antibodies and white blood cells to the area. This way, the bacteria can proliferate causing an infection. The only way to correct this problem is to retreat the root canal. That is done by opening up the tooth, then softening and removing the gutta percha filling material. After that is done, it’s a good time to search for extra canals or unusual root anatomy. All of the canals are cleaned thoroughly and irrigated with sodium hypochlorite. At this point, a decision is made on whether to place medication in the tooth and allow it to heal for a week or two or to go ahead and fill it that day. Retreatments do not enjoy the same success rate as original root canals, but they work often enough that they are sure worth giving a try.

Restoring Root Canal Teeth

Once a root canal has been completed, it is extremely important that the tooth be properly restored. If not, then there would be a good chance that the tooth could be lost permanently. The reason for this is the dental pulp which houses a collection of nerves and blood vessels in the center of the tooth will bathe the inner tooth layer (the dentin) with fluid, allowing the tooth to flex under load. Once the source of the moisture is gone, the tooth becomes very brittle. I always recommend that all chewing teeth have a crown placed soon after a root canal has been completed. I have even had the unfortunate experience of needing to extract a tooth only weeks after root canal treatment due to the tooth fracturing through to the root because it had not been properly restored yet. Some front teeth, if they have adequate remaining tooth structure, can be restored with just a filling.

Crown Over Root Canal Tooth

To place a crown on a back tooth, usually a crown buildup needs to be done. A crown buildup is a core of filling material that is used to replace the tooth structure that was lost in the root canal process and due to decay. This core may need to be retained with pins or a large post that is placed in one of the canals. With a quality, well-timed final restoration covering and protecting a root canal tooth, that tooth should give decades of future service.

Root Canal Complications

Most root canals can be done with little or no discomfort and will usually heal uneventfully. Unfortunately, there is an occasional poor soul who has post-operative complications. The most common of the complications is pain. Most pain is caused by inflammation. I always recommend that my patients who have undergone root canal treatment take an NSAID (non-steroidal anti-inflammatory) such as ibuprofen right after the procedure. Getting the anti-inflammatory into the bloodstream before the inflammation sets in is the key to preventing most post-operative pain. Infections can be the other main reason for post-op pain. A root canal is usually done on a tooth that is already infected. Through the root canal process, most of the infectious bacteria are removed. But there is still the possibility that some bacteria could be left at the tip of the root. Normally, the bioburden is greatly reduced from the root canal procedure, however, sometimes the body’s defenses can still be overwhelmed. Most infections can be handled with a single regimen of antibiotics. If you experience pain and/or swelling that is present for more than a couple of days after a root canal, you should contact your dentist immediately.

Root Fractures

Root fractures can be pesky little things to diagnose. A root fracture is a crack in a root of a tooth. It can be either horizontal or vertical in direction.

X-ray of a Horizontal Root Fracture

Horizontal fractures are usually a result of trauma. The survival of the tooth is dependent on where the fracture is located. If it is located in the apical third of the root (apical being the portion toward the tip of the root), then it may be possible to save the tooth. Otherwise it is implant time. Vertical fractures can start in the crown of the tooth, which is most common, or at the tip of the root. Root fractures may or may not have symptoms associated with it. If there are symptoms, they are usually pain while chewing.

Vertical Root Fracture

When fractures are present, they rarely will show on an x-ray, so the usual course of treatment is placing a crown to keep the pieces of the tooth from wedging apart while eating. If this does not work, then root canal treatment is performed. It is, many times, only after the symptoms don’t subside after having a root canal done will a diagnosis be made of a root fracture. Other times there may be a tell-tale thickening of the black line that surrounds the root on an x-ray giving indirect evidence of a root fracture. There is no known way to repair a root fracture and with the advent of long-lasting implants, the best solution of treating a fractured root is by removal of the tooth and placement of an implant.

How is a Root Canal Done?

Root canals are not the scourge of dentistry like they used to be. By using good local anesthesia techniques, a root canal can be performed with little to no discomfort. A root canal is done by first placing an opening into the pulp chamber.

Tooth Needing Root Canal Treatment

This is a hollow area in the center of the tooth where the dental pulp (a collection of nerves and blood vessels) resides. Once access to the pulp chamber has been obtained, the dentist will clean out any debris, whether it is live nerve tissue or dead, necrotic material. At this point, the actual root canal(s) are located. These are tiny channels that go through the root and exit at the end to communicate with the bone. Sometimes these canals can be very torturous to negotiate and many times requires a dentist with many years of experience to successfully complete the process. The canals are meticulously cleaned by a series of “files”, pin-like instruments. With each successive file, it will clean the walls of the canal, then the debris is flushed out with a sodium hypochlorite irrigating solution.

Root canal x-rays before and after

The canals are then dried and filled with a sealer and an inert material called gutta percha. The root canal has now been completed, hopefully without pain, and is ready for restoration.


Root Canal – When

The words “root canal” can strike fear into the hearts of mortal men. With modern techniques, most root canals can be performed with little or no pain. The first concern is proper diagnosis. No one wants to undergo root canal treatment – painless or not – only to find out that it was unnecessary. Some types of tooth pain can be reversible without resorting to a root canal. Removing decay and placing a sedative filling will sometimes do the trick. If there is pain along the “gum line”, the dentist can apply a desensitizer to the root to see if the condition improves. When one goes to the dentist with a toothache, it is not unusual for the culprit to be another tooth. This is called referred pain and it’s very important that the dentist performs a number of tests to determine the exact source. It is extremely important that the patient doesn’t take any kind of analgesic, such as ibuprofen or Tylenol, before an appointment. This can mask the symptoms and skew the diagnostic tests that the dentist performs. Another possibility is that the pain could be coming from something other than a tooth. During spring and fall, it is very common here in Atlanta for patients to appear in my office with “toothaches” only to find out that it was sinusitis. Taking adequate time during the diagnostic phase can save much time, money, and discomfort by getting it right the first time.