Root canal treatment consists of several steps that take place over several office visits, depending on the situation. These steps are: First, an opening is made through the back of a front tooth or the crown of a molar or pre-molar. After the diseased pulp is removed (a pulpectomy), the pulp chamber and root canals are cleaned, enlarged and shaped in preparation for being filled. If more than one visit is needed, a temporary filling is placed in the crown opening to protect the tooth between dental visits. The temporary filling is removed and the pulp chamber and root canal permanently filled. A tapered, rubbery material called gutta-percha is inserted into each of the canals and is often sealed into place with cement. Sometimes a metal or plastic rod is placed in the canal for structural support. In the final step, a crown is usually placed over the tooth to restore its natural shape and appearance. If the tooth is very broken down, a post may be required to build it up prior to placing a crown.