At first glance, a tooth may seem like a piece of hard bone that chews food. However, if cut in a cross-section, a healthy tooth has a network of nerves, arteries, and veins that respond to stimuli from the outside and the inside. Repeated drilling or cavities on a tooth allow oral fluids, water, chemicals, and bacteria to find their way into channels called dentinal tubules, and they could eventually affect the nerve inside the tooth. Sometimes the effect will manifest years after the initial insult.

What is Pulpitis?

Pulpitis is the pulp’s inflammation (the inner part of the tooth-bearing the blood vessels and nerve). The condition of the pulp can be described using three words: reversible, irreversible, and necrotic. Reversible pulpitis refers to a fleeting and low-grade inflammation sometimes caused by stimulation or sensitivity of the tooth. Irreversible pulpitis means the nerve is damaged or infected to the point that the tooth will not recover unless pulpal treatment is performed. Necrotic pulp means damaged, infected pulpal tissue that may no longer be responsive to stimuli or is infected. For irreversible pulpitis and necrotic teeth, the treatment is to perform a root canal.

The Root Canal Process

The root canal process involves preparing the tooth with instruments a little deeper than a large filling to locate the pulp and identify the canals. Tools like files and reamers, driven by a motor or used by hand, can remove the pulpal tissues. Solutions that clean and disinfect are used to irrigate the canals as the residue is suctioned away. Diagnostic equipment and radiographs (X-rays) can determine the length of roots. Eventually, the canals can be dried and filled with root-canal cement along with a non-metallic filler if the clinician determines. Numerous materials can be used, and some can be partially removed after filling the root to make space for a cemented post to support filling material and a crown. New materials and instruments help make this treatment faster and easier for the patient.

Benefits of a Root Canal

Intentional root canals are beneficial in several cases. Sometimes the tooth is in a rotated position, and a cosmetic and functional solution would mean reducing the area of the tooth that sticks out from the ideal arch form. When removing the tooth structure leads to encroachment on the nerve, an intentional root canal will ensure that the patient will not have to suffer undue pain later. Clinical judgment is also used when we approach close enough to the nerve that putting in a filling may irritate the nerves and cause the patient undue suffering.

Some people think that root canal treatment should not be done because there are always residual bacteria in the complex network of a tooth’s nerves that can lead to future infection and immune response.

I say the sooner we intercept problems, the better the chances of having a good outcome.

Root canal (endodontic) therapy requires special skills and intimate knowledge of the structure of teeth. Most front teeth have one canal; other teeth may have two, three, four, or more. Some lower front teeth have complex canal systems that make it challenging to find and clean them adequately. Calcified canals result when the pulp chamber lays down calcium salts on the inside of the canal in response to an insult to protect itself.

Sometimes these canals are hard to find and may require multiple visits or referrals to a root canal specialist (endodontist).

Some studies indicate that root canal treatment can have a 93 percent success rate five years after the treatment was initiated. The other 7 percent of teeth may need to be retreated, extracted, or have an apicoectomy performed. An abscess at the root of a tooth with a root canal, a post placed, and then a crown may not lend itself readily to being retreated. However, we can lift the gums can off the bone and remove the abscess at the root. After removing the infected root tip, a filling is placed in the remaining root to seal it from being re-infected. This procedure is called an apicoectomy, where the apex is the end of the tooth’s root. When a root canal fails or a tooth fractures vertically or horizontally below the bone level, the best option is to take the tooth out, remove the infection, place a bone graft in the area, and then place and restore an implant at a later date.

Extractions of teeth with root canal treatments present some unique problems because the tooth is more brittle and may break easily. This problem is common when patients do not follow up after their root canal by having the tooth crowned. Once the brittle tooth breaks, the tooth needs to be extracted. Cavities can also destroy a root canal tooth if the patient does not discover it in time; cavities do not cause a root canal tooth to hurt, and patients who do not see their dentist often may miss the fact that a cavity was developing.