My dentist told me my tooth needs Root Canal Treatment. What does this mean?

Root canal therapy is where the nerve in the tooth has died and has to be removed. When the nerve dies, as it decays, bacteria multiply and cause an infection. This leads to pain and an abscess if left untreated.  

The procedure is actually totally painless, and can be quite a relief if you've been in pain beforehand! The dentist uses small precision files to clean out the space in the middle of the tooth that contains the nerve. This space is then filled with a rubbery material, sealing it. This procedure allows a tooth to be kept that would otherwise have to be extracted.