Individuals undergoing root canal therapy for the first time usually have great apprehension and many concerns: Is the procedure painful, will this tooth have to be extracted later, how long will the tooth last, will it turn black etc. From the patient's standpoint, it is easy to see how these concerns would exist. Normally the procedure is painless; we will use local anesthesia prior to starting to work on the tooth.
Most restored teeth will last as long as your natural vital teeth. The reason for this is that as long as the roots of the endodontically treated tooth are properly nourished by the surrounding tissues, your tooth will remain healthy. It is somewhat of a paradox in that most people think that a root canalled tooth is a dead tooth. However, it is not a "dead tooth" as long as the roots of the tooth are embedded in healthy surrounding tissues that bathe the external surface and offer it nutrition.
For this same reason, it is seldom that a tooth will turn black. If appearance does become a prime concern, the tooth may be bleached or veneered (having a porcelain or composite facing placed over it). Most often, retention of the tooth and bleaching, veneering, or crowning are preferable to extraction and replacement with a prosthetic appliance (artificial tooth).