There are many reasons that your dentist may recommend a root canal treatment, listed below are the most common causes:
Dental Caries (aka cavities) is the most common infectious disease in the world, it affects rich, poor, and people from all ethnicities alike. It is affected by many different factors such as diet, oral hygiene habits and of course genetics. Cavities form when the bacteria in the mouth adheres to the enamel of teeth in the form of plaque. Plaque is known as a biofilm, which is a layer formed by billions of bacterial cells that work together to stay adhered to a surface and in turn become unreachable by the immune cells. Bacteria like to metabolize sugar (carbohydrates) and as a product of that metabolism lactic acid is the waste bacteria produce. That in turn allows the bacteria to dissolve their way deeper into the tooth causing them to multiply and infect the tooth. If this decay reaches the pulp (the nerve), pain develops as a warning sign that bacteria entered a space it shouldn’t have. The pulp normally is a sterile environment. This is called a pulpitis which translates to inflammation of the nerve. Inflammation occurs in response to injury akin to a cut on the finger, if you touch it, it will hurt! Seeking dental attention is highly advised at this point to avoid a dental abscess. If a root canal treatment is done at this stage the problem would be addressed with a high degree of success.
If the pulpitis does not get addressed, the pain (believe it or not) will probably subside after the nerve begins a process called necrosis. This process in other terms is nerve death. When the nerve “dies” the pain stops because the nerve is no longer there to sense the toxins and inflammatory mediators that would accumulate in the pulp during the early through late stages of pulpitis. Some people at that point may choose to ignore the problem because in their mind the issue has “resolved,” however this could not be further from the truth. Once the nerve dies the blood supply to it also dies and bacteria have free reign inside the tooth. This is very dangerous as slowly but surly the bacteria make their way to the bone through a small opening at end of the tooth roots known as the apical foramen. Once in the bone a localized infection occurs which in turn could lead to a full abscess (think swollen face and major pain). An abscess is an EMERGENCY and needs to be addressed immediately. Untreated dental abscesses can become life-threatening very quickly as the bacteria can spread rapidly and overwhelms the immune system.
Teeth like bone can fracture. Our teeth have to withstand many cycles of chewing a each day which can take a toll on the structure of the tooth as we age. Dental fillings can also structurally weaken teeth and make them more susceptible to developing cracks or fractures. The most obvious cause for fracture is trauma, which could be caused by an accident or a fall for instance. If the fracture line is superficial, a filling could potentially repair it with no additional treatment required. However, if the fracture reaches the pulp tissue (see a pattern forming?) then a root canal treatment would be necessary to seal the pulp space and prevent bacterial infection.
In some cases your dentist may require the space inside the canals for placement of a “post” which would help in the retention of a filling known as a “core”. This is more common in severely broken down teeth as well as fractured teeth.
This is a rare process by which the body starts to attack the tooth and slowly erodes the tooth structure from within the root. There are multiple different kinds of resportion, and your dentist would be the one to decide which type is affecting your tooth. It is a painless process, usually affecting a single tooth. We don’t know much about what causes it, but if caught early it is highly treatable.
I hope this gives you a summary of the major reason for root canal treatment. There are other reasons you dentist may recommend a root canal, however the majority of root canals done today are done for one of the reasons listed above. I will stress again, please do not ignore dental pain and visit your dentist regularly. If you visit your dentist every 6 months, they will be able to detect problems early enough that you may be able to avoid a root canal all together. As always if you have any questions please leave a comment or contact me through the contact page.