Decision No. 4: Are You Willing to Learn How to Simultaneously Use Intention and Restraint in Order to Follow the Canal to its Terminus? Q: How is the decision to learn how to “follow” canals is the third, and in many ways, the most important decision for optimizing endodontic predictability?
A: While eventually reaching the radiographic terminus of the root canal system is ultimately prerequisite to the Endodontic Seal, how and when to reach the end to the canal is the distinction that makes the difference in GlidePath management4 (Figures 3a and 3b). When a file does not easily follow down the entire length of a canal, it is due to 4 possibilities or a combination of these possibilities (Figure 3c). First, there may be pulp or necrotic tissue blocking the advancement of the file. Second, the angle of the access of the file may be different than the angle of incidence of the file. In other words, the curvature of the file does not sufficiently mimic that of the canal for the file to easily follow. For example, the dentist has placed a 5-mm length apical canal curvature on the file and yet the actual canal is an abrupt 1 mm turn, or perhaps an actual hook, as often is the case in maxillary lateral incisors, the DB root of maxillary molars, and the distal canal of mandibular molars. Third, the D1, or tip diameter, of the file is wider than the canal it is attempting to follow. Forth, the shaft diameter of the file is wider than the coronal portion of the canal. Restrictive dentin requires restrictive dentin removal before the file can follow deeper toward the radiographic terminus.5 Some endodontic teachers refer to this skill as “early coronal enlargement” or “crown down.”
Guideline No. 4: After removing coronal radicular restrictive dentin, follow your smallest file to the radiographic terminus. Never force or push. Irrigate copiously and after every instrument’s withdrawal. Be patient. The endodontic game is won or lost at decision No. 4.
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| Figures 3a to 3g. Decision No 4: Follow, No. 5: GlidePath, and No. 6: Rotary Shaping. (a) Small hand file follows to the radiographic terminus.(b) Obturated maxillary first molar. Note the rotary shaping and subsequent packing of the mesiobuccal canal follows the flow of the small hand file and preserves the position of the original portal of exit. Absolutely no apical transportation has occurred. (First molar endodontic treatment by Dr. Loubna Pla.) (c) Four dilemmas and 4 solutions during GlidePath preparation. (d) Small hand file following to radiographic terminus in wide apical curve. (e) ProTaper rotary (DENTSPLY Tulsa) wants to and can easily follow smooth GlidePath regardless of the extent of curvature. (f) Abrupt distal apical curve followed by small hand file. (g) ProTaper file is capable of abrupt turn shaping. |
