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Root Canal

  • Medical Author:
    Donna S. Bautista, DDS

    Dr. Donna S. Bautista, DDS, completed her undergraduate studies at the University of California, San Diego with a bachelor of arts in biochemistry and cell biology. During her time at UC San Diego, she was involved in basic research including studying processes related to DNA transcription in the field of molecular biology. Upon graduation, she went on to attend dental school at the University of California, San Francisco. In addition to her formal dental training, she provided dental care for underserved communities in the Bay Area through clinics and health fairs. She also worked toward mentoring high school students interested in the field of dentistry.

  • Medical Editor: William C. Shiel Jr., MD, FACP, FACR
    William C. Shiel Jr., MD, FACP, FACR

    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

Root Canal Related Articles

Root Canal Quick Overview

  • What is a root canal? “Root canal” is a layman's term to describe a dental procedure that is performed to preserve a tooth that is at risk of being lost due to deep decay, infection, or other forms of trauma.
  • “Endodontic therapy” or “root canal treatment” are the dental terms to describe this procedure.
  • Root canal treatment is the removal of the infection-prone contents within the tooth and its roots.
  • Subsequently, the resulting space is filled with an inert material to prevent infection. This treatment thoroughly disinfects the tooth's inner space.
  • Root canal treatment enables a tooth to remain intact to function and serve its purpose in the mouth despite losing its vitality. Vitality is the tooth's ability to sense pain, pressure, or temperature.
  • Prior to the implementation of root canal treatment, if a tooth had a large cavity or was abscessed, the only option was extraction of the “bad tooth.”

Tooth Anatomy

Within each tooth exists a pulp chamber and a root canal system that house the vital contents (pulp) of blood vessels, nerves, and connective tissue. The pulp chamber is a wide hollow space that is located within the visible crown portion of the tooth. The pulp chamber connects into the narrower canal spaces that are found within the root portion of the tooth. The anatomy of the root canal system can be very complex. Single-rooted teeth such as the incisors usually have at least one canal while multi-rooted teeth such as molars have at least one canal in each root. In root canal treatment, every single canal space of the involved tooth must be found and properly treated for the success of the procedure.

Root Canal Procedure

Root canal treatment begins after a proper diagnosis for an ailing tooth. Diagnosis involves a discussion with the patient regarding signs and symptoms. Dental examination, X-rays, and tests are performed in the mouth. Based on all the information gathered, a determination for root canal therapy is made if the tooth 1) has irreversible inflammation of the pulp (pulpitis) or 2) is dying (necrotic). Irreversible pulpitis is a condition where the tooth's pulp is inflamed from injury and will not recover. A necrotic tooth is a condition where the pulp has lost its vital blood supply and nerve function.

Root canal treatment is performed under local anesthesia. Prior to treatment, a rubber dam is placed in the mouth to isolate the tooth to be treated and to protect other parts of the mouth during treatment.

First, an access hole is made in the tooth with the dental drill. For posterior teeth, it is made on the chewing surface while for anterior teeth, it is made into the tongue (lingual) surface of the tooth. This access hole enables the dentist to reach the pulp chamber and root canals. Next, the pulp contents are removed with a small instrument. Afterwards, the inside of the tooth is thoroughly irrigated with an antimicrobial solution that eliminates infection. Small instruments are used to widen and shape the pulp chamber and canals. Widening and shaping the canals allows for thorough and proper cleansing throughout the tooth. Copious irrigation is done intermittently during instrumentation of the canals. Finally, the properly cleaned and shaped chamber and root canals are filled with a sealer and a warm soft rubber material called “gutta percha.” Once a good seal is achieved with the filling materials, the access hole is closed up with a temporary filling or a dental restorative material such as composite resin.

Next, the occlusion (bite) is checked and adjusted to ensure that no heavy biting from the opposite tooth can occur on the treated tooth. For posterior teeth (bicuspids and molars), root canal-treated teeth require dental crowns. Posterior teeth that have lost vitality are more prone to fracture from chewing and need the added protection of a dental crown. In comparison, anterior teeth (incisors and canines) tend not to bear as much force and usually do not require a dental crown. This assessment can be made by the dentist to determine what is best for each individual case. Typically, the crown procedure is done at a separate appointment by the general dentist.

How Long Does a Root Canal Take?

Treatment for a front tooth will usually take an hour. A molar root canal treatment will typically take an hour and a half. Timing depends on the complexity of the tooth being treated, access to the tooth, and the skill of the dentist.

Root Canal Specialists

The specialty of endodontics focuses on the treatment of diseases of the dental pulp. These dental specialists, called “endodontists,” have educational training additional years beyond dental school with a focus on preserving teeth with endodontic treatment. While much of their work specifically involves root canal treatment, endodontists perform other services such as diagnosis of dental problems, root canal retreatment, and apicoectomy (endodontic surgery to seal the root canal at the end of root canal system). General dentists are usually able to perform root canal treatment, but they often will refer more complex cases to the endodontist for co-management.

Root Canal Cost

The average cost for root canal treatment varies depending on geographic location and dental professional. Generally, dental specialist fees are more than general dentist fees. Anterior root canal treatment cost ranges from $400 to $1,200. Molar root canal treatment cost ranges from $700 to $1,700. With dental insurance, root canal treatment costs can be covered at 50% to 80%. Each insurance plan will differ depending on the insurance company and specific plan.

Aside from the price of treatment, one must also consider the price of losing a tooth that can never be naturally replaced. Tooth replacement with a dental bridge or dental implant can have a greater cost. Root canal treatment is often the best option for saving a tooth that would otherwise be extracted.

Root Canal Pain

Tooth pain can be managed with over-the-counter pain medications that treat inflammation (NSAIDs) such as ibuprofen (Advil, Motrin). If infection is present, antibiotics such as amoxicillin or clindamycin are prescribed as well. These medications can help relieve the pain prior to the root canal therapy appointment.

Oftentimes, dental emergencies involve an infected tooth with throbbing pain that needs root canal treatment. Unfortunately, the words “root canal” have become synonymous with pain. However, much of the pain occurs prior to the start of root canal treatment and not during the actual procedure. Root canal treatment is always performed under local anesthesia and usually does not hurt. With advances in pain management, many methods are available to provide comfort and ease concerns during the procedure.

Root Canal Recovery

Once the anesthesia wears off after the procedure, some discomfort can be present during recovery. This is especially true if swelling or inflammation was initially present. Oftentimes, the discomfort is mild and resolves in a few days. Post-root canal discomfort can be managed with over-the-counter medications such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol). Additionally, it is important to avoid chewing on the tooth until all of the tenderness is gone. This will promote healing of the surrounding tissues.

Root canal-treated teeth are more brittle and prone to chipping or breaking. For this reason, a dental crown is needed to properly protect these teeth that undergo heavy chewing forces. This particularly applies to the posterior teeth (bicuspids and molars) in the back of the mouth. Anterior teeth (incisors and canines) in the front of the mouth do not withstand the same amount of biting forces and do not usually require a dental crown for reinforcement.

Root Canal Complications

There are a few complications that can occur with the root canal treatment. A common occurrence is when a tooth is severely inflamed and requires an additional step to calm the tooth down. A root canal paste is placed within the tooth for a few weeks to relieve tooth pain. After this time period and the pain has resolved, root canal treatment can be completed.

In some situations, a blocked canal may be present and make it difficult to completely treat the root canal system. A blocked canal may be due to calcium deposits generated by the tooth. In this situation, every effort is made to work through the calcified area and seal the canal. If the effort is unsuccessful, endodontic surgery may be necessary to seal the canal at the end of the root within the jawbone.

Another rare complication that can occur during the root canal treatment procedure is lodging of a small broken instrument within the narrow canal. Despite the presence of the small object, sometimes the root canal system can still be properly sealed. If not, endodontic surgery may be necessary to properly seal the canal from future infection.

Another complication that may occur is a missed canal. Due to the complexity of the root canal system, an extra canal may not be found during the initial access of the tooth. Unfortunately, this leaves the tooth incompletely sealed and prone to infection and pain. However, advances in dental imaging with cone beam computed tomography (CBCT) have enabled dentists to have a more detailed analysis of teeth prior to treatment. These images help avoid this type of complication.

Root Canal Failure Symptoms

Once root canal therapy has been completed and adequate time has passed to allow the tooth to recover from infection or inflammation, the tooth should be back to normal function. Signs and symptoms of failed root canal therapy include sensitivity to cold or hot, swelling, and/or pain from chewing. Follow-up with the dentist or endodontist is necessary to determine further treatment to resolve the symptoms.

Root Canal and Special Populations

In children, primary (baby) teeth with a deep cavity or trauma that adversely affects the pulp may require treatment similar to a root canal. However, since primary teeth have different anatomy from secondary (adult) teeth, treatment is different and simplified. A pulpotomy is performed and involves removal of the pulp from the pulp chamber of the baby tooth. A medicated paste is placed into the chamber and the tooth is sealed with a filling.

If necessary, pregnant women can have root canal therapy. The standard protocol of using a lead apron for X-ray procedures is crucial for the safety of the mother and fetus. To manage pain while pregnant, over-the-counter pain medication is usually limited to acetaminophen (Tylenol). A consultation with the obstetrician is also important in high-risk pregnancies to determine the safest option for treatment.

Root Canal Complication


A toothache or tooth pain is most often caused when the nerve to a tooth is irritated, but there are numerous other reasons for a person to experience tooth pain. Risk factors for toothache include dental infection, gum disease, plaque, dental decay, injury, cracked teeth, poorly placed fillings or crowns, failing or leaking fillings or crowns, loss of a tooth (including tooth extractions), temporomandibular joint (TMJ) disorders, and obstructive sleep apnea. There are instances, however, where pain originating from outside the mouth radiates to the mouth, thus giving the impression that the pain is of tooth origin. This often happens when there is a problem with the jaw joint (temporomandibular joint or TMJ), ears, nerves, sinuses, or muscles. Occasionally, heart problems can give a sensation of tooth pain. Pregnancy can also be a risk for tooth problems that lead to pain. Due to fluctuating hormone levels during pregnancy, pregnancy gingivitis and tooth decay can occur.

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Reviewed on 11/17/2017
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