Tooth decay, fracture and other damage can all cause a patient to need root canal therapy. Left untreated, it can spread below the surface of the tooth into the dentin and the pulp of the tooth, causing an infection in the pulp. The pulp is the innermost part of the tooth anatomy that houses the nerves and blood flow.
If your dentist determines that you might benefit from a root canal, they will refer you to an endodontist for evaluation. The endodontist will evaluate the tooth and surrounding area and perform a number of tests to see if a root canal will save the tooth. If the tooth is deemed hopeless, it may need to be extracted.
What is the procedure for root canal therapy?
A root canal can usually be performed in one visit in less than two hours but if there are multiple canals and extensive infection, a second appointment may be necessary to complete the procedure. The front teeth only have one canal and can typically be treated in one 30 minute appointment but the molars and premolars can have up to five canals and could take two visits.
To begin, the doctor will apply a topical numbing agent to the soft tissue around the infected tooth. Then a local anesthetic is administered via injection to fully numb the entire area. They will likely use a bite block to prop your mouth open which can be much more comfortable for the patient so they do not have to focus on keeping their mouth open the entire time. A rubber dental dam is used to isolate the tooth being treated which helps keep it clean and dry during the procedure.
Once the patient is fully numb and comfortable, they will begin by drilling a small access hole through the tooth all the way to the pulp. Small cylindrical files are used to reach down into each canal and clear out the infected pulp tissue. Once the pulp and infection is completely removed, an antimicrobial solution is applied to remove any remaining bacteria and to keep the tooth from becoming reinfected while the patient waits to have the tooth permanently restored by their dentist.
Finally, the canals are dried and temporarily filled with a rubbery material called gutta-percha and the access hole is covered with a temporary filling. These materials keep the tooth protected from reinfection until the tooth can be restored. On occasion, the patient may be advised to have the tooth restored as quickly as possible but most of the time, your dentist will want you to wait a couple of weeks to allow the tooth to recover from the root canal treatment.
After a couple of weeks, your dentist will have you in to restore the tooth. They will remove the temporary filling and the gutta-percha before inserting a permanent core buildup and covering the tooth with either a composite filling or a porcelain crown. Root canal treated teeth become brittle over time because of the lack of blood flow so even if your dentist is able to place a filling, you may eventually need to have that replaced with a crown.