From: Terry Pannkuk
To: ROOTS
Sent: Tuesday, August 10, 2010 10:54 AM
Subject: [roots] Puzzle Case: Fracture or Groove?

This is a good teaching case I’m going to use for the UCSF residents.

This was my dilemma this morning.  This patient presented with symptoms suggesting recurrent endo pathosis.
Preop radiographs attached.  Perio probings resulted in some bleeding and a couple of 4mm pockets:



This wasn’t’ the type of presentation I would automatically recommend a CT Scam on.  There was no suspected fracture,
no narrow pocketing, and no suspected false paths, just an over-instrumented, under filled, missed MB2  garden variety
type retreatment.  If a fracture existed I wouldn’t’ expect it to be worth the cost benefit of the patient paying for
a CBCT. Of course I mentioned that there was a remote chance a preop CBCT would be helpful, but the patient didn’t
think that remote opportunity of prediscovery was worth jacking up the fee. I didn’t’ either.

When I accessed the tooth I discovered some perplexing issues, primarily a white line extending deep along the fucation
side of the palatal canal to the DB canal orifice.   I also troughed out a mesiolingual groove fairly conservatively.
There was no apparent patient MB2 and it seemed confluent. I don’t’ try to be too aggressive the first visit and trough
these out more definitively the second visit when the irrigants and CH have softened the fin areas more ideally.
Being too aggressive the first visit hogs out these areas too much and unnecessarily.



Puzzle question:  What do you do when presented with a line like this to determine whether it is a crack or a groove?
, or does it already look like an obvious crack to you?

The rest of this case to follow in a subsequent email.  - Terry



Terry, Interesting case. I would follow the groove towards the furcation using munce burs. If fee was not an issue,
would a scan be helpful in determinig the presence of additional root anatomy? (ie. a seperate MB2 ) If the additional
radiation is minimal ( equivolent of two maxillary x-rays) is there an obligation to take the scan?

If the CBCT gives us additional info, and like the scope, we don't know on which cases the information will be helpful,
than should we not be charging for the scan at all, and incorporating the expense into our fees like we do with other
tools for treatment?

I am having a hard time justifying charging the patient for a scan when having the scan may be helpful to diagnosis
and treatment in so many situations.

Ultimately as the expense of the COne Beam decreases, I believe we will not be charging for its use.
(similar to the microscope, and digital x-rays)

The presence of the groove into the palatal root canal concerns me. I rarely see "grooves" present in this fashion.
Looking forward to more info, - Mike

Imo its not a typcal location for an fracture but it is an location you can find grooves.
If it is an fracture its a goner so you have nothing to lose (but time and money) by chasing the white line.
Just for fun(if i had an CBCT) i would offer an free CBCT if it turns out to be an groove, if its an fracture
i would charge it because an CBCT is cheaper then an next RCT session.

Sincerely René Stevens

p.s. nice puzzle

I would be tempted to take the crown off to get more information - Bill

Good analyses proposed!

The Schilder technique doesn’t typically crack roots with spreader loading, lateral condensation does. The pluggers
are not supposed to contact dentin walls with the Schilder technique.

I’m not sure taking the crown off would do more than raise her investment level on an already suspect tooth, but maybe
it would allow better interproximal probing, there weren’t any crack lines through any of the marginal ridge walls
though as viewed internally.

I was very hesitant to trough this type of white line unless I knew it was a root with anatomy that could accept it.
This is primarily the reason I don’t like automatic CT scaming on every patient.  The COD (critical option determinant)
wasn’t elucidated until access revealed an entity that required further exam.  A CT after preliminary cleaning, shaping,
and placement of a radiopaque material in the root canal system yielded much better information after starting treatment,
not before.

There is a tendency to trough these things out until you perf.  Maybe that doesn’t matter if it’s split anyway and
needs to come out, but if it isn’t a crack and you trough a narrow fused portion and perf, you’ve essentially ruined
a savable tooth.  I’m always thinking about a spreader loaded crack when considering retreatments.  In those cases
the crack can exist along almost any orientation and might not even be visible coronally.  I didn’t get a photo of
the initial access but there was no core, just Cavit and a giant wad of gutta percha in the pulp chamber floor.

This was my strategy, good or bad:



If the transverse view showed the DB and P roots were not fused                                                                                                  If it looks like this (DB – P fused) it’s probably a groove and a good prognosis for endo.
If it looks like this (DB - P fused) then it’s probably a crack and the tooth needs extraction

I performed just enough troughing and smoothing in the areas I knew were thick portions of the root requiring
cleaning and shaping.  I explored the MB2 extending the access toward the mesial marginal ridge and troughing
the mesial lingual groove toward the MB1.  I didn’t complete definitive troughing which might have revealed a
white dot indicating an MB2 or short ML system because the suspected crack necessitated a need for a CBCT
( I was simply going to get more information later anyway so being aggressive with the ML trough wasn’t
necessary until later).  There was no patent MB2 and I simply used the composite finishing burs to conservatively
trough out the line incompletely.

Regarding the suspected DB-P groove/crack.  I now figured I wanted a CBCT.  The crack-groove went down the buccal
wall of the palatal canal, so I became immediately interested in the lingual wall.  If there had been a line
through the lingual wall (opposite wall) of the canal it clearly would have been a crack.  There wasn’t.
There also wasn’t a mid-lingual sulcular defect.

I didn’t show this photo initially or it would have suggested an interest in the status of the lingual wall.
(no apparent crack line which is good sign)




Well this is what I found on the CBCT.  You can see the fused bridge connecting the DB and P roots.
On the transverse section and what it looks like on the Dicom view.  Good news! - Terry



Funny enough...I have seen this before....on one of my patients who came from Montreal....
I reckon it's a fracture from an overhanded Schilder technique...warm vertical...using a Schilder plugger and
a freeking mallet...now the the other thing is...some  palatal root architecture does exhibit grooves,
but that is on the outside...needless to say, I extracted the tooth...all symptoms went  - Molar  Del Sud

Thanks for sharing this Terry,
I would never have thought of the fused DB and P root. Again, something learned which I otherwise would have
learned through a failure of mine. Grtz, - Rafaël

Thanks Terry, Have 3 questions:

-Can't  we have 2 separate roots with a coronal groove?
-Can't  we have 2 fused roots with a crack ?
-Can't we have a crack that is located only on 1 side of the canal? - Amir

Good questions, but from an objective assessment standpoint I’m concerned about the probability of existing
anatomy being associated path defect or a normal anatomical defect.

It’s not a matter of what we can possibly have as it is in esoteric research.  In clinical practice it’s more
important to consider what we are likely to have.  Good clinical judgment, determination of treatment options
and a predictable, high success rate depends upon understanding anatomy, your experience with anomalous and
common anatomical root presentations, and the intuitive skills to know how to employ experience, science,
and developed clinical technique in a way that results in idealized treatment for the patient coming into your
office with a unique presentation of disease.

So to answer your questions in a clinically meaningful way:

We can have 2 separate roots with a coronal groove but if look down one of the roots and see an apical line
extension it is unlikely  to be associated with a connecting web or fin if it exists apically beyond the
coronal dentin bridge that would associate it with natural root anatomy.

We can have 2 fused roots with a crack, but if one predicts it is associated with a dentin bridge representing
root fusion, then subsequently discovers the prediction of the anomalous root anatomy to be true, there is a
more robust likelihood that the entity represents a groove, not a crack.  It’s the same as considering a
prospective study representing a higher level of evidence than a retrospective study.  It may still be a
single anecdote but you should consider the power of your prediction as having meaning after later discovery.

We can certainly have an incomplete crack located on 1 side of a canal, but that doesn’t represent a null
hypothesis conclusion to the question: Is it a groove or a crack.  I was simply more interested in finding
a crack on both opposite walls which would direct my decision not to treat.  The fact it existed on one side
simply left the question unanswered and propelled me to continue on with the plan of continuing endo treatment.

I still haven’t definitively determined that the white line is not a crack.  I’m simply moving forward with
the endodontic plan because it continues to be the best probabilistic option considering the revealed evidence so far.

In my opinion, it is unrealistic to have perfect success; but it is realistic to make the best decision and
utilize ideal judgment based upon critical thinking, experience, and meticulous attention paid to discovered
clinical signs, symptoms, testing, and observation. - Terry

Thanks for ur time and those answers Terry. Have another one:

Could u tell us what u recommend for dealing with these grooves? e.g.: when one prepares  2 canals perfectly till
the confines of their anatomies but he knows that there is this potential reservoir which is left untouched
(even with the EOM :):):) & which acts like a shelter for all kind of pathogens and substrates they could use.

I have the feeling that most of the time we're filling in  "3D"  canals which are only C&S in 2D...
(or maybe it's only a personal frustration) - Amir

Amir, That’s a very good question that can only be answered with an opinion.  The research that would provide
a definitive answer is absent and wholly inadequate to provide a clinician with any meaningful information that
can be used to determine clinical judgment.  It is therefore primarily art.

In my opinion, limited access, like those promoted by the biomimeticists/dentin preservation extremists results
in gross remaining sepsis that insidiously destroys the attachment apparatus or leaves it in a chronically
inflamed partially destroyed state, setting up incipient furcation bone loss that progressing to progressive
periodontal bone loss, and subtle symptoms that are rarely recognized as having an endodontic disease origin
creating nagging patient morbidity.

On the other hand there is a practical limit we can go toward eliminating all subtle groove extensions because
our current instrumentation and techniques do not allow us to treat these areas definitively. I do believe
from recall data and observations that we can reduce the intracanal space and the potential to allow communication
of pathogens down to a level that leads to predictable clinical success in the vast majority of cases.
The art is determining “how much troughing” is required to eliminate the potential for recurrent endodontic disease
versus ripping trough fragile root sections predisposing to perforation or fracture.

With regard to the case I presented, I plan on troughing one millimeter or slightly less into the observed fracture
line at the pulpal floor level, feeling that it will be clinically “safe” to do so on the next visit.
I’m going to be a little more aggressive troughing the mesiolingual groove knowing I have more root width to work with
and that there might be a separate mesiolingual canal.  Here’s that CBCT section that I did not show before
(I do not like routinely taking preop CBCT’s because I feel that it would tend to suggest more troughing than might
tempt me to trough more than I prudently should; there is no PA lesion at the MB root apex so looking too aggressively
for an MB2 or mesiolingual system doesn’t seem too wise) :-  Terry