Case• 48. An endodontic problem
A 60-year-old female patient has pain from a root-treated tooth. What will you do?
The patient presents complaining of discomfort from a lower left back tooth. The filling was lost from the tooth about 4 months ago.
History of complaint
She has suffered intermittent problems since the tooth was root canal-treated 2 years ago. Pain is triggered by biting on the tooth and changes in temperature have no effect. The symptoms have remained similar in intensity ever since the root canal treatment was completed.
The patient has always attended regularly for dental treatment, requiring occasional treatment for failed restorations over the last 10–15 years.
The lower left second permanent molar was originally treated endodontically because the patient developed acute pulpitis. Two attempts at root canal treatment were carried out before the intense pain subsided, with the root canal filling being placed at a third appointment. An endodontic instrument fractured in one of the root canals at the second appointment and the patient was informed of this by the dentist. A temporary restoration was placed to allow a period to assess resolution of symptoms but the patient preferred not to return to the same dentist, feeling that the treatment had gone wrong.
▪ How do you assess the case so far?
Several features of the history are significant.
Pain on biting and well-localized pain indicate periapical periodontitis and the cause is almost certainly failure of the root canal treatment.
There was a fractured instrument. This probably means that no apical seal would have been achieved in that canal, reducing the chances of successful treatment.
The provisional restoration was lost 4 months ago. This indicates a complete loss of coronal seal to the root canal system that would allow microleakage of bacteria and their toxins along the length of the root filling. The extent to which this will have occurred is time-dependent. As a general rule, if the root canal filling has been exposed to the oral cavity for 3 months or more, retreatment should be considered even in the absence of clinical signs or symptoms.
There is no facial swelling or tenderness associated with the tooth.
You examine the patient following the procedure outlined in problem 47. The lower second molar has a large cavity distally with obvious caries and exposed gutta percha root filling in the pulp chamber. It has tilted mesially and is tender to percussion. The third molar has a large, poorly contoured amalgam restoration.
A radiograph is necessary and a periapical view of the teeth in the lower left quadrant is the most appropriate.
▪ What information do you wish to obtain from the radiograph?
• What is the nature and quality of the previous endodontic treatment?
• Are any root canals detectable? Failure of treatment may be caused by failure to detect or fill all canals. Any remaining canals in teeth that have large carious lesions, restorations, marked toothwear or suffered trauma may be sclerotic as a result of tertiary dentine formation.
• Is there periradicular radiolucency? This would indicate persistence of infection or inflammation.
• What is the root morphology? The number of roots and their orientation can be identified. Root curvatures and diameters can also be observed; however, it is important to remember that radiographic images are two-dimensional representations of three-dimensional structures. Canals are often much wider buccolingually than can be appreciated in a conventional radiograph.
▪ The preoperative radiograph is shown inFigure 48.1. What do you see?
The canine and premolars are restored and no caries is present, though there is significant toothwear anteriorly. The tilted second molar is root-treated and the fractured instrument is visible in one of the mesial canals.