Apex Locators in the diagnosis of perforations
Cases of the day
From: Richard Schwartz
Sent: Tuesday, April 03, 2001 07 49
..... Back to the grindstone today. Had a couple interesting cases.
The first had a second distal root that curved sharply to the buccal.
I've left behind some nickel titanium in roots like that before.
Fortunately, this one turned out well. The second case was a 3rd molar
(I think) with a C-shaped configuration.
The opinions and photographs within this web page are not ours.
Authors have been credited|
for the individual posts where they are.
- Photos courtesy of Richard Schwartz - www.rxroots.com
From: Barnett, Fred
Sent: Tuesday, April 03, 2001 18 08
I am at Temple Univ. today, and I am keeping your cases on my screen to show
the students that don't yet belong to ROOTS. If you have time, can you
describe exactly your method, from the time you find all of your orifices.
First file in, etc. Your work is just outstanding.
Also, I presented a poster that supports your larger MAF sizes, and Trope's
group did the same using culturing methods....
it significantly removes more intra-tubular bacteria (which is
important for those of us that might not be able to predictably entomb them
within the canal walls). Also, Kerekes and Tronstad showed that the
"standardized technic" , read larger MAF's, yield predictable high success
rates after 5 yar follow-up. That study was from undergraduate cases, and
compared the results to a step-back, smaller MAF's, method in Scandinavia.
From: Guido Costa
Sent: Wednesday, April 04, 2001 02 59
Very nice cases Rick.
Did you do them in one appointment or two? Did you use Profiles 06 taper?
From: Richard Schwartz
Sent: Wednesday, April 04, 2001 20 55
Thanks, Guido. They were both done in one appointment and with the .06 Profiles.
As are most of the cases I post.
From: Richard Schwartz
Sent: Wednesday, April 04, 2001 20 53
...... here is my technique after the canals are
located. It varies, of course, depending on the situation.
I start with RC prep and a size 10 hand file, and place it to an
estimate of the working length, if it will go there easily. Then I do a
quick step back with a size 15 and 20. Next I open the orifices a bit with
the smallest orifice shaper. It is size 20 at the tip. I go as far into
the canal as it will go easily. Then I use size 2 and 3 Gates Glidden burs.
At this point I irrigate and dry, place RC Prep, and try to get an initial
length determination with the apex locator. I follow with xrays from
several angles with files in the canals. Then I use the .06 Series 29
Profiles. I start with the size 4 (red) and then the 3 (yellow) and 2
(silver) if necessary to get to my WL and establish patency. If I can't get
to length right away, I go back and forth, gently, with the size 3 and 2,
with some small hand instruments mixed in. In most cases they work their
way down the canal nicely. I keep RC Prep in the canals and every few
instruments irrigate with SH. Once I have achieved patency with the
rotaries, I may use the apex locator again if I'm not confident of my
Once I have a size 3 or 4 to my WL, I irrigate with SH and alcohol, and
do a standard crown down technique with the .06 Profiles. In most cases I
do an initial preparation to size 6 (36) or 7 (45). Then, by hand, I place
a Lightspeed instrument (a slightly larger size) to my WL to determine if
the canal has been prepared adequately. If the Lightspeed instrument goes
easily to WL and doesn't feel like it is engaging the walls of the canal, I
enlarge it further with the Profiles or sometimes with the Lightspeed
instruments. Cliff Ruddle talks about guaging and tuning to determine how
much "deep shape" is necessary. This is the same process, only using the
Lightspeed instruments rather than standard hand files. The Lightspeed
instruments, as you know, are sort of like Niti Gates Gliddens. They give
you a much better tactile sense for guaging than a hand file, particularly
in curved canals. The last step is to check patency with a size 3 Profile.
I go to the RT or a bit beyond. In a perfect world I have the canal
prepared to the constriction with patency to about size 20.
Once the canals are prepared I do a cone fit xray. Then I let the
irrigants soak in the tooth for a few minutes while I do something else. My
assistant irrigates initially with liquid EDTA for about two minutes to
remove the smear lay and then goes back to SH and alcohol. I dry the
canals, place Kerr EWT sealer with the Diadent gp cones, downpack with the
System B and backfill with the Obtura. We don't usually restore the access
opening with a permanent restoration, but we have a deal with our referrals
that they will restore them asap, in many cases the same day.
I am sure my technique is not much different than yours or anyone elses.
We are all, to a large extent, influenced by the same people. My apical
preps are a bit bigger than most of the cases posted in Roots, but I'm not
sure that it makes a difference. It isn't much trouble to enlarge them,
however, and it makes me feel better. - Rick
From: Fred Barnett
Sent: Thursday, April 05, 2001 02 31
The Kerr Pulp Canal Sealer seems to be very popular with the warm gp
technic. Why is it more popular than other ZOE-based sealers? And, why is
there silver in this sealer? thanks!
The purpose of the silver in Kerr's sealer is for radiopacity only. (at
least that's my understanding) -Jeff
From: Richard Schwartz
Sent: Thursday, April 05, 2001 06 16
I used to use Roth's sealer, about 1/10th the cost, but noticed that my
partner's obturation looked denser than mine. Couldn't have that, so I
switched. I think that's the only benefit (?) the silver provides. The
puffs also show up better. - Rick
From: joseph dovgan
Sent: Thursday, April 05, 2001 06 31
I use Roth's 811 strictly because it's at least 1/10th the cost and we
used it in my grad progam at Iowa. Some folks also say they ge more
post op pain and flair ups, but I think there are alot more important
variables - Joe D
From: Guido Costa
Sent: Thursday, April 05, 2001 07 16
I use Roth's 801. I have seen some folks adding more barium sulfate to the
mix to make it more radiopaque. I don't know of any study that look into
this, but I think one of the residents at Bethesda is actually looking into
some of this variables. - Guido
From: Jerry Avillion
Sent: Thursday, April 05, 2001 1:21 PM
..The Kerr Pulp Canal Sealer seems to be very popular with the warm gp
I've noticed that, too.
....Why is it more popular than other ZOE-based sealers?....
I keep asking all the BU guys why they use the Kerr's sealer as opposed
to anything else, but I've never got a good answer.
...And, why is there silver in this sealer?....
Maybe the silver makes it work better, it sure makes it LOOK better on
Sounds like a great grad student project. Compare success and failure
of teeth sealer with Kerr's sealer vs. Roths. - Jerry Avillion
Fort Smith, Ark.
MCV '84, MCV Endo '86
From: Fred Barnett
Sent: Thursday, April 05, 2001 1:33 PM
The silver is to satisfy the aesthetic requirements of a "nice" post-op
case.....IB Bender, circa 1981.
From: Uziel Blumenkranz
Sent: Sunday, April 08, 2001 22 40
As a BU graduate I still keep using the Kerr sealer. Maybe following the old
trend of following the leader. the results seem to be nice, although could
probably be duplicated with other sealers. I agree with Ben. If the old man
said it was kerr sealer you used, so it was. Harvey's thesis also showed
excellent results with this cement so we keep using it.
Best regards and give it a try. - uziel--
From: I. Blake McKinley, Jr.
Sent: Tuesday, April 10, 2001 02 08
As usual, you have raised a great question.
You have asked why Kerr sealer is so popular with the WGP technique.
Some have postulated that it is popular because the silver content shows more
puffs. I thought it was an interesting question, and since I could not recall
a ready answer, I reviewed my notes from Dr. Schilder's lectures.
Dr. Schilder studied under Dr. Grossman who provided significant mentoring for
Dr Schilder. From what I could piece together of the story, at the time solvent
based techniques were popular. Due to the shrinkage experienced from these
techniques, Dr Grossman advocated a sealer that did not contain any amount of
solvent. I would suppose his interest was to minimize the potential of shrinkage.
The Kerr sealer is based on Grossman's sealer formulation which is a slightly
varied form of Riekert's formula. Apparently, the stability of this formulation
was the most acceptable of the available sealers.
Years after Dr. Schilder developed the WGP technique, the Kerr EWT formula was
developed to improve the working time characteristics when heat was used.
The Sealer came before the development of WGP, so the content of the sealer
has nothing to do with more demonstrable puffs or greater silver content
(if this is true).
Bottom line, the sealer came before the technique. Dr Schilder likely advocated
this formulation because his mentor advocated it. Knowing Dr Schilder and
understanding his respect for Dr Grossman, they likely would only advocate this
formulation based on their studies and not on their whims. Certainly, the working
characteristics of this sealer are very acceptable for this technique.
Are there currently other sealers that would perform at least as good as Kerr?
I don't know.
Certainly, if other BU Alum have additional input as to why this formulation has
been so popular among WGP advocates, they should give it because this information
is not likely the whole story.
Blake McKinley, Jr., DDS
From: B. Harvey Wiener, DDS, MScD, FRCD(C)
Sent: Tuesday, April 10, 2001 03 57
To: Blake and Jerry,
As you may know I am a old time BU puffer(Class of 69) and I published 2 articles
with Herb Schilder ( took me years to call him Herb) in the Triple O Journal Nov1971
and Dec 1971. These were a summary of my MScD thesis on various physical properties
of 9 root canal sealers.
To my knowledge Herb always liked Kerr sealer more for what it didn't do than
what it did!
1.very tissue tolerable and stable upon setting, important features if you think
(or know) you are going to "puff". This is absolutely not the case with other
Zoe based sealers such as Grossman's original formula which never seemed to set
completely leaving residual eugenol for many hours or days to irritate the
periapical tissues when the sealer was expressed beyond the confines of the
apical terminus(AT or RT whichever you prefer). This was not the case when this
sealer was used for what it was intended to be used for within the confines of the
My former partner and I did a test for 1 week using Grossman's sealer and puffing
in our then "normal" way and the phone rang off the wall with post op pain and
irritation. I still puff but much less so than in previous years probably because
I use a 20" monitor with my digital imaging and those little puffs look so much
larger now that it keeps me a 'touch" shorter than before.
2. Our study showed that Kerr sealer was the most stable sealer with regard to
shrinkage and dimensional stability compared to the others we tested then.
Obviously we are playing with the physical properties of any sealer when we
introduce heat to the "mix". These sealers were not invented for use with the
amount of heat we use with the warm vertical compaction techique and some have
just not been usable in these conditions.
I'm sure I missed a few points but it has been 32 years since I did this project.
Those of us that continue to use this sealer seem to always agree with what Herb
used to say and that is "Kerr sealer has withstood the test of time" and since
we can't yet find anything better....what works continues to work well. Look
forward to your comments. Harv