To extract or not to extract?  This is the question that faces many teeth that fail to heal following root canal treatment.  It is less likely that an implant would be recommended for a tooth requiring a first-time root canal, and more likely for a retreatment.  Because implants are gaining much popularity of late, they have become the preferred solution to a failing root canal.  Some dentists may consider root canal retreatment too complicated, unpredictable, or unsuccessful to recommend.  The truth is that retreatment can be a very successful procedure, 80-90% on average.  When there is a clear cut reason to explain why a root canal is failing, such as a missed canal, a poor root filling, or root canal recontamination through a leaking restoration, there is a great possibility that the retreatment will remove the source of the infection and allow the tooth to heal.  Some retreatments may not be as predictable, such as those with separated instruments, canal blockages, or root perforations.  Apical surgery may be an option for the more complicated retreatments.  Sometimes it is not advisable to perform a retreatment due to a poor prognosis, and an alternate treatment should be done.  Implants are an excellent option for replacing missing teeth, but they should only be considered if it has been determined that extraction is necessary.  Both root canals and single-tooth implants share the same survival rate of about 94%.  However, implants have been shown to require more treatment intervention to maintain their survival rate.  They also require more time to function than a tooth receiving root canal therapy, meaning that it can take a significant amount of time before you can use your implanted tooth.  There are many factors that must be evaluated to determine the treatment that's best for your tooth.  If your tooth has been recommended for extraction and implant, ask if root canal is an option.