Each tooth has at least one root and each root usually contains one canal. Inside each canal, you can find the pulp which contains blood vessels and nerve tissue. The blood vessels supply the tooth with needed nutrients and the nerve provides sensation to temperature and other types of sensations.
Sometimes teeth are so deeply damaged by deep caries or fillings that they become painful. At this point, your options are either extract the tooth or try to save the tooth with root canal therapy. Root canal treatment allows you to keep the tooth for a longer period of time rather than extracting it, as long as it does not become infected and your body does not reject it, it will remain in place and function like any other tooth.
Yes. Quite often you can have a chronic infection with no discomfort. They are like ticking bombs that will eventually develop catastrophic results with intense pain. Since patients cannot see inside their jaws, they have a tendency to ignore the problem. If you had a visible and painless infection in one of your toes, would you ignore it?
There are multiple reasons why root canals fail, but what they all have in common is the presence of bacteria which ultimately results in failure. Usually retreating the tooth will solve the problem; however, the success rate is typically lower than a first-time root canal. Common reasons for a root canal failure are:
Leakage is the most common reason why root canals fail. No matter how well a root canal is treated, some bacteria will always remain within the canals. Over time the restorations will leak and supply the bacteria with much-needed nutrients. Eventually, they will work their way toward the tip of the root and cause inflammation and eventually infection. This is when we consider the root canal to be failing. Therefore, having crowns with good margins is crucial in order to minimize/stop the leakage for as long as possible.
As explained in the previous paragraph, one can never clean the canals 100%. That being said, one should try to clean and remove all possible pulp tissue as effectively as possible. Any remaining tissue will serve as a food source for those remaining bacteria. If your tooth has a more complex anatomy, the instruments will not be able to reach many areas. As a result, the tooth will have a higher chance of failure. However, It is still worth saving the tooth rather than removing it.
Sometimes root canals will fail due to invisible fracture lines. These may not be visible to the naked eye but they resemble a three-lane highway for oral bacteria. The failure rate is guaranteed and it occurs rapidly depending on the extent of the fracture line. Extraction is the only option as the tooth cannot be predictably treated.
The goal is to stop leakage into the tooth. This is why every root canal has to be sealed with a filling, within two weeks of completion. Certain teeth will require a crown as well. The temporary filling is only meant to seal the tooth for up to two weeks. It will leak after two weeks even if it remains in place! Some patients do not return until the temp filling has fallen out after a whole year. These teeth will have a much higher failure rate.
If you are 100% numb you won’t experience any discomfort during the procedure. So why do people hear negative stories about root canals? That’s because they were not 100% numb. When you have a severely inflamed tooth, a local anesthetic will not be able to fully numb the tooth. This is why dentists remind patients to take care of their root canals before they develop pain. Unfortunately, many patients postpone their treatment. These individuals are generally the ones that end up with a negative experience.
In addition, some individuals are difficult to numb no matter what procedure they need. These types of patients will have difficulty regardless of the treatment needed. However, there are certain injection techniques that help the majority of these patients. If you have had difficulty getting numb, inform your dentist.