Inside of every normal, healthy tooth is a space that contains a nerve, artery, and a vein called the “pulp.” Inside of the clinical crown, the part of the tooth that can be seen above the gum line inside the mouth, is the pulp chamber. Inside the roots which are imbedded in bone, surrounded by a ligament, and covered with skin, or gingiva, are the root canals.
What is root canal treatment?
Patients often refer to the procedure as having a “root canal”; the correct procedural name is “root canal treatment”, or the treatment of the canals within the roots. When the tissue, or pulp, inside your tooth is damaged (for any one of a number of reasons) a root canal treatment is performed in an effort to save your tooth.
After your tooth is anesthetized (numbed), an opening is made to create access to the pulp chamber and canals. The contents inside your tooth are removed with an instrument called a barbed broach. The wall on the inside of your tooth is smoothed and cleaned using tiny files and various solutions. The inside of your tooth is then filled with a material called gutta percha and cement that seals the tip of the root.
Simply stated, a root canal treatment cleans out the damaged tissue inside of your tooth and fills the space with a rubber material that is very compatible with your body. A tooth in need of a root canal treatment is said to be in a state of Irreversible Pulpitis or Pulpal Necrosis, meaning that the damage to the nerve, artery, and vein is not repairable.
Symptoms Leading to Root Canal Treatment
The symptoms of pulpal death, or the death of the tooth vary from person to person and from tooth to tooth. Typically, when a patient reports a toothache there are five questions that can help determine whether or not the tooth is dying. This list of questions is a guideline in helping to diagnose irreversible pulpitis.
Is your tooth hot or cold sensitive?
If the answer to #1 is yes, does the pain linger for 3-5 minutes or does it subside when the hot or cold is removed?
Is it pressure sensitive (does it hurt to chew or bite)?
Does it hurt without being provoked?
Does it wake you up from a sound sleep?
Sometimes only cold sensitivity is seen, but it is usually extreme cold sensitivity that lingers for five minutes after the cold is removed. Sometimes only pressure sensitivity is noted, but pain without provocation, waking the patient at night, and extreme heat sensitivity are strong indications your tooth is dying.
Cold sensitivity and pressure sensitivity could mean something other than pulpal death, such as a filling that is too high or a microscopic crack in your tooth. Pain that wakes someone from a sound sleep could be from an intense episode of clenching and grinding; a potentially damaging habit that, as of yet, has not caused irreversible pulpal death, just tooth pain.
Sometimes patients have no symptoms, but a dark spot around the tip of the root on an x-ray is found, indicating the tooth has died.
A pulp tester may help the dentist in the diagnosis of the pulp health, however, the pulp tester only indicates if there is any live tissue remaining inside the tooth. Since the pulp tissue doesn’t all die at the same time, a pulp tester may not be as reliable as the x-rays and answers to the above questions.
What Creates the Need for a Root Canal Treatment?
All living tissues, including teeth, need a blood supply to allow healing following damage from trauma. When we cut our finger there is an enormous blood supply to the wound, allowing it to set up an inflammatory response and heal. The problem with our teeth is that the blood supply is very small. For example, when we get a bad cavity and the pulp gets irritated, our body has the ability to build up protection from the inside of the tooth, protecting the pulp. That built in protection comes from our blood supply. Sometimes, when the tooth is ‘injured’ bad enough, the elements necessary to heal the tooth cannot get to the injury fast enough due to the very small blood supply and the tooth can die. A more detailed explanation to causes leading to Root Canal Treatments follows:
Deep tooth decay - First, read the article on tooth decay. Left untreated and allowed to progress, tooth decay can become severe enough that it either gets too close to the pulp, irreversibly irritating the pulp or the decay progresses into the pulp, creating an infection inside the tooth. Both situations may lead to pulpal (tooth) death. The bacteria involved in this infection are called anaerobes or bacteria that grow and reproduce without oxygen. Anaerobic bacteria produce gases that expand when heated, press on the infected nerve, and create intense pain. Bacterial invasion usually requires a regimen of antibiotics.
Trauma - There are two forms of trauma that may cause your tooth to die: acute trauma (like getting hit in the face with a baseball) or chronic trauma such as tooth grinding (read the article on TMJ/TMD). Chronic tooth grinding presses the tooth into the boney socket, compressing the artery and vein, choking off the blood supply. Over long periods of time, this habit may cause pulpal death.
Dental Treatment - Poor home care leading to repeated dental treatment may cause the death of your tooth. Many times a tooth that has been repeatedly filled and eventually needs a crown, dies after the crown is prepared. Often the patient wants to know what the dentist “did to my tooth”. In reality, the tooth has been repeatedly traumatized (yes, it’s traumatic to keep getting decay in a tooth and having it filled over and over) and the crown preparation, which may have been recommended years earlier, causes the tooth to start having symptoms.
Tooth Movement - If a tooth is moved too rapidly, such as in Orthodontic treatment (braces), pulpal death can occur. A more important variable in pulpal death during tooth movement is the condition of the tooth prior to the applied force. Teeth that have sustained years of trauma from being repeatedly filled or a tooth that has suffered years of clenching and grinding can die, even if they’re moved slowly. Teeth can only handle a certain amount of stress or trauma before they die.
What Are the Risks of Having a Root Canal Treatment?
Failure - Sometimes a root canal treatment will simply fail. This means, for some reason, the treatment performed could not completely remove the infection. When this happens, the tooth can be retreated, usually by a specialist (an Endodontist). An Endodontist is a general dentist who attends 2-3 years of specialized education beyond dental school.
Retreatment- This may be attempted if the initial treatment fails.
Apicoectomy- If the initial treatment fails and the retreatment fails, an apicoectomy may save the tooth from extraction (removal). This is a minor surgery designed to expose the root tip and remove a small portion of the tip of the root and place a filling into the end of the root.
Extraction- If all treatment fails, an extraction is necessary. In fact, an extraction is the only alternative to a root canal treatment.
Perforation - During the opening or filing of the tooth, an instrument can accidentally perforate the tooth from the inside out. Typically, this causes the loss of the tooth.
Broken instruments - If an instrument accidentally breaks inside the tooth, the longevity of the tooth depends on the dentist’s ability to file and fill the tooth beyond the broken tool to the tip of the root.