Case of the Month November 2011

This month, I am presenting a retreatment case that proved to be more challenging than I imagined. The patient is a 53 y.o. male who was referred for an evaluation of tooth #30. He was asymptomatic at the time of initial examination. His medical history was non-contributory. The dental history was as follows: He had the root canal treatment performed approximately 10 years ago by his dentist at the time. He was recently seen by his dentist who noted that the root canal treatment was less than ideal and that there was an apical pathosis associated with the mesial root. Clinical exam reveals that tooth #30 has a PFM crn present, negative percussion or palpation tenderness, normal periodontal probing depths. Radiographic examination reveals that the tooth has had previous RCT, there is a threaded post present in the distal root. The obturation of the mesial and distal canals is well short of the radiographic apex. The distal root appears to have been obturated with a carrier based material, the mesial root reveals ill-fitting master cones based on their curled appearance. There is a RL lesion associated with the mesial root. The radiographs are as follows: .
The clinical diagnosis is Previously treated #30 with asymptomatic periapical periodontitis.
Retreatment of the root canal was recommended and the patient decided to proceed with the treatment. The problems that are anticipated when the case is viewed radiographically are as follows: Preservation of the crn (if possible), removal of the threaded post in the distal root, removal of the carrier-based obturation in the distal root, negotiating the meisal canals after removal of the existing gutta-percha. The mesial canals appear to have been ledged during the previous treatment and this always poses a significant challenge. Careful exploration of the canals with pre-bent small files and a gentle touch is what is needed in these situations. At the initial visit, the tooth was accessed, the threaded post was removed with an ultrasonic and copious water to prevent as much heat transfer to the root as possible. The carrier was removed (Soft-core) from the distal root and this canal was negotiated to the apex. The mesial canals presented with a more difficult challenge to negotiation. The canals were severly ledged and also joined, as evidenced by the drying of one canal led to the other canal being dried as well. I was unable to complete the case in the first appointment. Calcium hydroxide was placed and the patient was reappointed. The interim radiograph is as follows:

At the second appointment, the patient was asymptomatic, the tooth was again accessed and the process of trying to negotiate the mesial canals was ensued. I think I went through approximately 50 hand files in trying to gain patency. Being persistent paid off and I was finally able to gain access to the apex. The case was cleaned and shaped, and obturated with warm gutta-percha. The completed case is as follows:
This case demonstrated a challenge to canal negotiation. Proper technique and an understanding of my goals was essential in order to properly treat the case. Certainly, I could have initally opted for a root end resection. However, I felt fairly confident that I could manage the retreatment without having to go to an apicoectomy. I welcome any comments or feedback regarding this case. Thank you again for entrusting my office with the care of your valued patients.