In the center of each tooth is a tissue called pulp. Its job is to help with growth by building enamel, dentin, and cementum that makes up the structure of the tooth. Once the tooth is developed, its job is complete. Unfortunately, it can then cause problems if it becomes infected and inflamed, irritating the nerve. This is when root canal therapy is needed.
"Root canal therapy involves removing tissue, cleaning, shaping, and disinfecting that canal space where the pulp was and then filling that canal space with root filling material," Richards said. "Because the tooth's already grown and developed in its position, we can safely remove the pulp and effectively save the tooth."
Even though the pulp tissue is gone following a root canal, the tooth still retains some sensation. It just isn't the same sensation as before. "It still has a nerve sensation coming from the structures that are supporting it into the jaw bone," Richards said. "If you tapped on the tooth, you would still feel that percussive sensation. If you extracted the tooth, it would hurt."
A root canal can be done one of two ways. Conventional root canal therapy involves removing the pulp through the top of the tooth, while surgical root canal therapy is done through the bone underneath the gum. "Surgical root canals are usually done when a previous root canal is failing, or if there is some other restoration to the tooth we don't want to disturb," Richards said.
All teeth have pulp and nerves, so all teeth are candidates for root canal. But four teeth—your four interior teeth, or the ones that come in first and are used most throughout your life—are most likely to need the procedure. "Obviously the first molar comes in when we're six and it's exposed to everything we expose our teeth to, longer than any tooth in the mouth," Richards said. "So probably the single most commonly treated tooth is the upper/lower first molar."
The best way to avoid a root canal is to take care of your teeth. Brush and floss daily and see a dentist for regular check-ups. Also, pay attention to any tooth pain and seek professional help when it happens.
"We have varying degrees of damage to the nerve, creating different diagnosis," Richards said. "But once a tooth becomes a little bit sensitive to cold and a little bit tender to chew on, we know it's starting to affect the nerve in the tooth and the supporting structures that support the tooth in the bone. The earlier we are able to treat it, the less likely you are to need a root canal."