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February 2004 – Disassembly Retreatment Prevents Surgery
A 47 yr. old male patient was sent to me for consultation regarding soreness and percussion sensitivity in the area if the maxillary 2nd premolar. The tooth had a history of endodontic treatment in another office with subsequent post and core crown restoration. I noted a lateral radiolucency in the Preop image and I suspected that the lack of adequate canal cleanliness and possible lateral canal was the source of the problem.
Fig. 1 - Preop
The possible treatment alternatives consisted of disassembly retreatment or surgical intervention. When considering Retreatment, we are always faced with the possibility of just placing an apical seal and relying upon previous clinicians for cleanliness of the remaining canal space. I was unsure as to the exact location of the lateral canal leading to the lesion, although it appeared to be on the distal side. There was no way to tell if the accessory canal could be accessed from the buccal surgical approach and I was not happy with the idea of resecting the root to that level. For most Endodontists, this is not the preferred approach. If we are going to take ultimate responsibility for the endodontic status of the case, then we prefer to have cleaned,shaped and filled the entire canal space ourselves. In that way we ensure that we have treated the entire canal system to the best of our ability.
In this case, the crown was fairly new. I suggested to the patient that although there was some inconvenience and extra cost involved in disassembly and remake of the restoration, I felt there was a good possibility that we could avoid having to perform surgery if an adequate non-surgical result could be obtained.
Fig. 2 Working length file that was long.
After consulting with the referring dentist regarding the particulars, the crown and post were removed. An Electronic length was obtained ( Fig.2) that turned out to be "long". Since the foramen was larger than anticipated, the EAL only registered properly when adequate contact with the canal walls had been made by the file. The file was through the canal when this happened. The length was then adjusted and the canal was cleaned entirely with hand instruments. The apex was gauged at a size #40 instrument.
Figure 3 shows Cone fit with Kerr sealer.
A non-standardized M-F cone was fit with a 2 sec. chloroform dip technique. The GP cone was rinsed with alcohol and air dried to confirm that the integrity of the dipped portion.The canal was filled with Kerr sealer and a nice accessory canal was visible as suspected. The patient's symptoms disappeared and we are awaiting restoration.
Figure 4 Final canal fill with anticipated lateral canal.
Sealer track is noted in the PDL space, where the original working file was "long".
Fig. 5 - Final canal fill shifted shot
Some teeth are best treated with disassembly and conventional retreatment rather than surgery. In some cases, these restorations may have only relatively recently been cemented and that places the Endodontist in a tough position. He must now recommend to the referral and the patient that this work be destroyed and then remade..
It is understandable that the referring dentist is reluctant to remake the restoration a second time if he doesn't have to, because of the costs involved in the new post/crown. This is because Insurance carriers most often not cover the cost of conventional retreatmentor re-restoration. Insurance carriers will frequently cover the cost of surgical retreatment of these cases because it is considered "separate treatment category" by many plans. Therefore, there is a certain amount of financial pressure that can sometimes be exerted by both the patient and the referral to "fix the case surgically", because it involves the least cost to these two principles.
The retreating dentist must resist this pressure and stick to his guns when he sees the need to retreat the entire canal space. This sometimes involves extra work for the Endodontist, extra cost to the patient for remake of the restoration ( OR possible cost to the dentist if the crown has just be done recently !) - However, doing the retreatment in this manner is infinitely better than leaving the restoration in place and attempting to deal with the problem surgically.
Ultimately, the responsibility for the entire case rests with the retreating dentist and if that is the case, all parties must understand that disassembly/re-restoration is part of the cost involved in obtaining the best clinical results.