Past the Gutta Percha Point

Going to the dentist isn't all that bad. Sometimes a little pain, sometimes brain rattling drills, sometimes larger than life Novocain needles to the tune of "Just a Little Pinch." In the long run with the help of my dentist, it is great to have kept most of my teeth, to be able to smile, to eat a steak, or bite an apple. Better than this is the relationship between my dentist Bill and me and I would like to think between Bill and his patient Michael.

I have had my share of cavities, tooth aches, root canals, tooth extractions, caps, and bridgework. I take care of my teeth, brush and floss regularly but my mouth seems to have a mind of its own. Bill is always there to make my mouth right when it has gone off the deep end. More than that, it is the way he does it. He is friendly. He is professional. He is skilled. He is putting his children through college (but who isn't?)

I started out my career in dentistry (as a patient that is) with Bill's father. When he retired, senior's daughter Colleen and son Bill took over the practice. They were stuck with some of the old patients, like me.

Over the years Bill and I have had many a conversation while the Novocain was setting in and we continue to do so. We have had a number of conversations that were one sided on Bill's part when my mouth was full of tools and sometimes even two sided under the same circumstances, tools and all. Many of our conversations run into the after-hours of his dental practice. Often I get scheduled at the end of Bill's day so we can talk as much as we want without fear of dental assistants giving us dirty looks. 

We talk politics, health, news, family, loved ones, religion. We have recommended books to each other and then held a Dental Chair Book Club. We have e-mailed links to interesting information. We have shared photographs, pros and cons of Apple Computers, and a love of Mexico. We have challenged each other, supported each other's views, and best of all fostered creative thought.

Over the years, Bill and I have grown up together, learned from each other (speaking at least for myself,) nurtured one another, and often look forward to seeing each other again. Today, in fact, I told Bill that maybe we should regularly scheduled meetings at Starbucks so we could "share" and not have to wait until the next trauma. And psychosomaticly, maybe my mouth wouldn't act up hoping for a reunion.

This is what Bill and I did today:

P.S. A Gutta Purcha Point is from the Gutta Purcha Tree which produces natural rubber used in sealing the root of a tooth after the root canal has cleaned it up. The following article discusses the pain in detail :•)

Allan S. Deutsch, D.M.D., F.A.C.D.

Fitting the Gutta-Percha Point

THE ENTIRE endodontic  procedure, from diagnosis through instrumentation, can be said to be just a prelude to the “fill.”  The filling of the canal with gutta-percha visually displays to everyone all your preceding efforts and work that have led to this last step in completion of the root canal therapy.  The most important part of this last step is the fitting of the gutta-percha point.  The point must fit well enough so that you know with the utmost predictability what the final result will look like, even before you complete the procedure.  If the preceding instrumentation has been done well the point will be very easy to fit and the result will be predictably excellent. So, exactly what do we do in fitting the point? 

Constant modification of our instrumentation over the years has led us to the EZ-Fill^® SafeSider™ technique. This sequence of instrumentation allows us to fill the canal with gutta-percha easily, effectively, and quickly.   The key to the fill is to make sure that the last two nickel-titanium instruments, the orange 30/.04 and the brown 25/.08, go to the apex easily with no binding.  Once this is accomplished, we can fit the gutta-percha point and fill the canal.

I use the tapered gutta-percha points (Figure 1).  The 25/.08 prepares the canal to a .08 taper.  Therefore, I use a .06 tapered gutta-percha point.  Each manufacturer’s point varies slightly from the others, but most of the .06 tapered points are very close to specifications.   I use either a 25/.06 or a 30/.06 gutta-percha point.  I select the point depending on how easy it was to instrument to the apex with the 30/.04.  This instrument opens the apex to a #30.

I now take a gutta-percha point out of the box and place it in the canal.  I use a locking forceps and grasp and lock the point at my reference mark.  I remove the point and measure it on a finger ruler.   Let’s assume for demonstration purposes that the working length of the canal is 20 mm.  When I measure the point, it will either be right on the mark, long, or short of the measurement.  If it measures 20 mm (about 80 percent of the time) you are now ready to fill (Figure 2).  If it is long (usually by about 1 mm), just take a pair of scissors and cut off the extra mm.  Replace the point in the canal, lock it at the reference point, and measure it again.  Usually it will now fit.  If it does not, just repeat the cut step.

If it is short by 1 to 2 mm, you have a little work to do.  There is an area in the canal that is a little difficult to clean.  It is located about 5 to 8 mm from the apex.  With our technique, you have instrumented 4 mm short of the apex to a 40 and you have gone down as far as you can go with the #2 Peeso. This sometimes leaves a “no man’s land” in that 5 to 8 mm zone from the apex.  This is usually where the gutta-percha point is binding. There are two ways to handle this :

• Select a different gutta-percha point. They are not all exactly alike and one point may be more or less tapered than another.
• Reinstrument this 5 to 8 mm area.

You can reinstrument by :

1. going deeper with the #2 Peeso if possible
2. going 5 mm short of the apex with a #45 stainless instrument then
3. going 6 mm short of the apex with a #50 stainless instrument then
4. going 7 mm short of the apex with a #55 stainless instrument then
5. going back to the apex with the 25/.08. 

Once the “no man’s land” is reinstrumented, a new gutta-percha point should fit to the measurement. Now that you have fitted the gutta-percha point to the canal, you are ready to place cement into the canal and permanently seal the root-canal system.  

September-October 2001