Richard Mounce, DDS
During a recent hands-on course, I recommended a crown down instrumentation sequence as a way to improve the distribution of irrigants and tactile control over instruments. However, a participant told me that the step back technique was better because "it works just fine for me." I was struck by the person's reticence to even consider another approach to instrumentation. Being open minded pays huge dividends. Staying abreast of innovations is essential to improving clinical results, personal satisfaction, and profitability.
The philosophy of "it works just fine for me" is akin to someone using slides for presentations in a digital world. It could be done, but why? Most endodontists and general dentists who are comfortable performing root canals use a blend of materials, systems, and ideas. In other words, their treatment is based on a wide range of experiences. Many of the products they use are the result of an open mind and a desire to learn. For example, I strongly advocate the K3 rotary nickel titanium system (SybronEndo, Orange, CA) for the bulk of my rotary instrumentation. However, in many cases for several unique indications, I will employ the ProTaper SX file (Dentsply Tulsa Dental, Tulsa, OK) in the coronal and middle third. In addition, I employ the GT Accessory files (Dentsply) at 900 RPM (usually the 35 tip size) for bulk gutta percha removal in the coronal half, along with various other methods. Inherent in these recommendations is the fact that I have used virtually all of the commercially available systems in the USA. I've kept an open mind to find what works in my hands. Doing every root canal the same way — always using step back, for example — is like a sports team running the same play every time. It might work some or even most of the time, but there will be significant failures — one size does not fit all in any endeavor, especially endodontics.
Endodontic excellence requires more than just finding one method of treatment and always using that technique. Other than what I call "The Endodontic Truths" (listed below), there is little that is agreed upon within this specialty. But hearing all opposing viewpoints in clinical endodontic controversies (and there are many) has great educational value to the dentist.
My endodontic truths are:
• The goal of endodontic treatment is the three-dimensional cleansing, shaping, and obturation of the root canal system from the canal orifice to the minor constriction of the apical foramen. In other words, endodontic treatment should mimic extraction. Extraction works because the entire pulp is removed, the diseased pulp is removed, and the potential for healing exists. There are two essential components to this: 1) Biomechanical cleansing of all pulp tissue from the canal system, and 2) The complete obturation of the entire prepared pulp space.
• Straight line access is essential.
• Correct determination of true working length (TWL) is critical. There are four methods for determining TWL: Radiographic, electronic apex location, tactile sense, and bleeding point determination. The greater the number of confirming methods of TWL , the better, as no single method is always correct.
• Canal preparation should resemble a tapered funnel with narrowing cross sectional diameters as one moves apically.
• Copious irrigation is desirable. Specifically, I recommend use of a side vented needed delivering 5.25 percent sodium hypochlorite (90-150 cc in total per molar) including exchange for a minimum of 30 minutes in the canal after the bulk of the pulp has been removed.
• Coronal seal (at least a bonded build up), ideally the same day the root canal is completed, is most desirable to prevent microleakage.
Aside from the above, controversies exist on a wide range of endodontic topics. Remaining open minded to accept new ideas and advances can prevent the tunnel vision that results from "It works just fine for me," and, ultimately, gives our patients the best possible care.
Dr. Richard Mounce is in private endodontic practice in Portland, Ore. He lectures worldwide and has published numerous articles in the Journal of Endodontics. Dr. Mounce also writes "Endo Made Easy," a bimonthly tips feature for Dentistry magazine, and a quarterly column for Endodontic Practice in the UK. Contact Dr. Mounce via email at linek firstname.lastname@example.org. Visit his Web site at www.mounceendo.com.