When we are dealing with apical pathology, we should always have in our mind that intra-canal infection is by far the most common cause of disease. In a case such as the one shown below, no canal can be seen radiographically, and no canal was found by the dentist that accessed the tooth. But we should remember that a pulp that has undergone pulp canal obliteration will still in most cases have either vital or infected tissue contained within it at a microscopic level.
The patient above presented to me for treatment of acute apical abscess. The central incisor had been accessed twenty years earlier, but no canal could be found (despite the large access). At that stage an apicectomy was performed with an amalgam retrofilling placed. The tooth remained asymptomatic for twenty years prior to the abscess forming.
Consider the options we have available:
1. Endodontic treatment, with or without apicectomy;
3. Extraction and bridge/implant.
The previous apicectomy, pulp canal obliteration and large access make this tooth appear to be a difficult to manage case, and this could be mistaken for it having a poor prognosis. But we have to be careful not to over-think the case. With a microscope available, endodontists expect to be able to prepare canals in most teeth such as the one shown above, and therefore take care of the intra-canal infection.
One option would be to take a CBCT to further assess the presence of a canal. In this case however, there has already been an access made, and we are assuming the canal is infected and necrotic, so the decision was made to remove the restoration to see if any canal could be located. The canal was located, prepared and dressed with calcium hydroxide. No exudate was produced, and there was a definite stop at the level of the amalgam retrofilling, The symptoms resolved and four weeks later the canal was filled. The patient was advised that an apicectomy may be required if symptoms recurred. The presence of the amalgam apically, is not by itself sufficient not make apicectomy an obvious option.
Two year review revealed the tooth remained asymptomatic, and healing of the apical pathology had occured. This was despite the amalgam retrofill remaining.
The main point to take out of this is that treatment of intracanal infection should be our first priority. Secondly, when we manage to get rid of intracanal infection, then the material used to fill the canal isn’t so important, as long as we maintain a good coronal seal to prevent reinfection. Thirdly, when you see a calcified canal such as this one, it may be a good idea to refer to someone who has experience in these types of cases if this is an option, as the location of the remnant of the canal can be challenging.