1) & 2) X-ray series of tooth #14 showing a large, old silver filling in a patient who had been experiencing root canal pain. Note the decreased size of the pulp chamber known as teeth calcification. 3) X-ray of endodontic file lengths. Note that the calcified mesial root of #14 initially prevented instrumentation. 4) Final endodontic obturation showing that the mesial root of #14 was located and treated. Chronic inflammation in the dental pulp due to the presence of large, old fillings can increase the difficulty of root canal therapy. Earlier root canal therapy should be considered in these situations.