Products and techniques that will make your endodontic experiences better!
By Kenneth Koch, DMD, and Dennis Brave, DDS
Just because you have made the commitment to rotary instrumentation doesn't mean you can now throw away your hand files. In fact, hand files are an integral part of any rotary technique, whatever system you use. Consequently, we thought this would be a good opportunity to discuss hand files and their use in rotary endodontics.
The first issue is the alloy of the hand file. In our opinion, you should be using stainless steel hand files because all hand files should be pre-curved prior to placement in a root canal. Due to its shape memory, one cannot predictably pre-curve a nickel titanium file. Consequently, stainless steel hand files that can be pre-curved should be used as a complement to rotary files.
Another tip for hand file use is the smaller the canal, the closer to the tip you place the curve. This will facilitate not only entering tight canals, but it will also help you follow the curves (figure 1). Too often we see clinicians using files that have a gradual curve. This is not recommended. We want the curve in the apical third of the file.
While the above issues apply to hand files in any technique, what is the prescribed use of hand files in a true rotary technique? The main uses of hand files in a rotary technique are to confirm coronal patency, to establish working length, to confirm an anatomic channel in difficult cases, and to maintain apical patency.
To fully address these hand file challenges, Real World Endo, in partnership with Brasseler USA, has developed a new series of hand files as part of our "EndoSequence System." In fact, the "EndoSequence" hand files are the only hand files designed specifically to complement rotary files. But what makes these files any different from existing files? Let's take a look.
We have extended the length of the handle and made it somewhat similar to a baseball bat. The result is increased leverage for the clinician due to the extended length (figure 2). This is particularly helpful when "working" a file in a canal. Furthermore, one side has been flattened to act as an anti-rotation feature. This is important because the "EndoSequence" hand files should be used with a quarter turn and push-pull motion. The concept of "working a file" means taking it back and forth in a push-pull motion that incrementally increases the size of the canal. This is particularly important when confirming coronal patency.
We also prefer the longer version (25 mm) when establishing working length, because its length facilitates the use of an apex locator. Regardless of the apex locator employed, a 25 mm file is easier to work with (when determining length) than a 21 mm file. Additionally, once we get to length, we can effectively "work" the file (due to its extended handle) and establish a precise anatomic channel. This will likewise facilitate the use of rotary files to the working length.
Because of increasingly difficult canal morphology, we have designed the "EndoSequence" hand files in sizes 8, 10, 12, 15, 17, and 20 (see picture below). This size selection not only gives you the ability to "work" these files with less resistance, it also allows you the opportunity to confirm anatomic channels in severely curved canals.
When you really think about it, the inclusion of a size 12 and 17 makes a lot of sense. Routinely, when you jump in file size from a #10 to a #15, you have committed yourself to a 50-percent increase in apical tip size. That's why a #15 hand file feels so different from a #10. However, when you go from a #10 to a #12 hand file, you have only increased the apical tip size by 20 percent. This is much easier to manage in small size canals.
It is an exciting time in endodontics. Certainly, we are very enthusiastic about the advances in rotary instrumentation and obturation, but we are also confident that you will find the "EndoSequence" hand files a wonderful complement to your rotary instruments. Simply put, hand files are a necessary adjunct to any rotary technique. Hopefully, these new hand files will make your cases better and your life easier.
Dr. Dennis Brave is a diplomate of the American Board of Endodontics and a member of the College of Diplomates. In endodontic practice for 27 years, he was the senior managing partner of a group specialty practice. Dr. Brave, formerly an associate clinical professor at the University of Pennsylvania, currently holds a staff position at The Johns Hopkins Hospital.
Dr. Kenneth Koch is the founder and past director of the program in postdoctoral endodontics at the Harvard School of Dental Medicine. In addition to having maintained a private practice limited to endodontics, he has written numerous articles on endodontics and maintains a faculty position at Harvard.
They can be reached at Real World Endo at (866) 793-3636 or through www.realworldendo.com.