Anatomically, root canal is a space within the tooth filled with soft tissue - pulp. The pulp contains blood vessels, nerves, connective tissue, all a tooth needs to grow. Dentin and enamel are hard tissues that cover the pulp from above. The pulp plays an important role especially during tooth maturation, but once it becomes mature the pulp plays the role of sensation transmission and supply the tooth with supply it needs .

Root canal therapy is a procedure used to repair and save a decayed or infected tooth.
The aim of the treatment is to save a tooth that is severely damaged. There are several reasons that bring to the tooth decay:

• Infection in a mouth cavity that brings also to the tooth inflammation
• Repeated dental procedures that bring to the weakening of the tooth’s protective layers (enamel and dentin)
• Faulty crowns that cup the tooth
• Cracks or chips in the tooth
• Any trauma, even without visible cracks or chips

The untreated pulp inflammation causes a severe pain and brings to the abscess (collection of pus) formation. There are also other symptoms of root canal inflammation besides the pain:

• Sensitivity to hot / cold food and fluid even after removing of irritants
• Tenderness to touch and chewing
• Darkening of the tooth
• Swelling, which may spread to the face, neck, or head
• Bone loss
• The formation of a source of pus  that will drainage an inflamed fluid into the gums or even into skin.
• In some cases no symptoms occur

A general dentist or endodontist provides this technique. His goal is to remove bacterial infected zone and dead tissue from inside of the tooth. The modern techniques allow doing this procedure maximally comfortable for a patient. This is a relatively painless and extremely effective procedure. The pain from the root canal inflammation is much more severe than a treatment itself.  In most cases more than one visit may be needed. The number of visits depends on the depth of injury. Some of dentists do it in a day; others prefer clean a cavity and continue the procedure in a few days.    

The procedure is consists of several steps:

1. First, a dentist takes X-Ray image to detect the depth of injury.
2. Once a procedure begins, a local anesthesia is usually prescribed. A patient feels a bit of pinch in an area of injection and numbness during the whole technique.
3. A rubber dam (a sheet of rubber) is placed to keep the tooth clean and dry.
4. The dentist opens a way to the root canal with the tools like a small drill.
5. The infected pulp with nerves is removed from the cavity. The dentist constantly irrigates this field with water or sodium solution to remove the debris.
6. The dentist may choose an additional step to put antibacterial medications in the cavity for several days.
7. At the next appointment or on the same day a dentist fills the tooth cavity with a material called gutta-percha.
8. if the root canal filling went well,the dentist would put a tooth filling to close the cavity and restore the masticatory and occlusal function of the tooth .

A patient feels a pain relief in no time.