The prospect of a root canal can provoke fear and loathing. Its reputation as a gauntlet of pain is widespread and of long standing.
But many people have been relieved to find that root canal treatment generally does not live up to its nefarious image. The tooth in need of a root canal is a greater cause of pain than the root canal treatment itself.
If a tooth's nerve and pulp is inflamed or infected, if gums are tender, or if heat or cold are a cause of pain and sensitivity, these may be warning signs that you are in need of a root canal.
Pulp and nerve tissue must be removed from the tooth. If infection is present, a medication is applied inside the tooth. At the next appointment, the tooth is filled with a sealer paste and gutta perch. It is topped off with a filling.
Later a crown, or crown and post are possible ways of covering the tooth to protect it and make it functional again.
"Root canal treatment is highly successful; the procedure has more than a 95% success rate. Many teeth fixed with a root canal can last a lifetime."
http://www.webmd.com/oral-health/root-canals?ecd=wnl_day_052610