Most teeth can be treated. Occasionally, a tooth cannot be saved because the root canals are not accessible or the root is severely fractured. However, advances in endodontics are making it possible to save teeth that even a few years ago would have been lost. When endodontic treatment is not effective, endodontic surgery may be able to save the tooth. Some teeth are so broken down or decayed that they cannot be restored or do not have adequate bone support, so while a root canal could be performed, the long-term prognosis of the tooth due to other factors, makes spending money on a root canal a poor investment.