Root Canal Endodontic, I thought the definition of endodontic esthetics was the filling of the root canal to the radiographic apex. Little did I realize that I was creating unneeded post-operative pain and possibly setting up a chronic inflammatory response, which might lessen the chances of a successful endodontic treatment for my patients. The inflammatory response triggers the type of pain that occurs immediately after the anesthetic wears off. This pain is characterized by a sharp intense quality with throbbing in the affected area. Where was I going wrong?
The endodontic literature during the 1990s reported that the anatomic apex is often (at least 50 percent of the time) 0.5 to 1.0 mm short of the radiographic apex. The anatomic apex is usually defined as the apical constriction in the canal at the cemento-dentinal junction. If the canal is instrumented and filled to this level, the instrumentation and filling material will not impinge on the periodontal ligament or the alveolar bone.
dental low speed handpiece was that I was instrumenting and filling to the radiographic apex (Figure 1). Consequently, I was instrumenting at least 50% of the time from 0.5 to 1.0 mm past the apex and into the ligament and bone. For thirty to forty-five minutes, I was using my reamers to poke tiny holes and rip the periodontal ligament. The result of this was nasty pain as soon as the anesthesia wore off.
Using an apex locator will enable you to determine accurately where the anatomic apex is located. An x-ray will not permit you to locate the anatomic apex. We do not routinely take working-length x-rays any longer. Because we are no longer instrumenting to the radiographic apex but rather to the anatomic apex, the amount of post-operative pain has been substantially reduced.
Now that we are filling to the anatomic apex, we are experiencing an increase in success rate. Figure 2 shows a gutta-percha filling pushing through the anatomic apex, which is approximately 2.00 mm short of the radiographic apex. We recently published our office success rate in a study in the June 2001 issue of Practical Endodontics. In the article we reported a 94.1 percent success rate. This is at the very high end of the reported literature. You never get 100 percent success because cases fail due to root fracture and inadequate or failing restorations.
dental curing light is a radiograph of a tooth that is rotated, showing the bucco-lingual view. You can see that the anatomic apex is at least 1 mm short of the radiographic apex. Figure 4 shows a dot of gutta percha at the apical end of the palatal canal. This dot is approximately 1 mm short of the radiographic apex. The dot tells us that the canal is curved at a 90-degree angle facing the buccal, so in actuality you are looking at the end of the gutta percha facing directly buccal. If you tried to reach the radiographic apex, you would have to perforate the root and come out the top.