Endodontic Cases of the Month


“Come on the risin’ wind, we’re goin’ up around the bend” – Creedence Clearwater Revival

Welcome to our case of the month series where I’ll highlight some of the more interesting anatomic, diagnostic, and surgical cases that cross my path in the span of a typical month. In my 13 years of clinical practice, I’ve found that anatomic variance can be one of the most challenging, yet rewarding, aspect of endodontic therapy. The case you see here is one that ended up as something of a surprise given the look of the pre-operative radiograph. There’s a suggestion of a conical shaped MB-DB root with some typical curvature towards the distal. While working the case, there was a much more distinct feeling of serious curvature. The fact that MB2 progressed in the same manner wasn’t helping either. However, using a Dentsply Sirona Vortex Blue 15/.04 and WaveOne Gold Primary I was able to clean & shape the canal without complications and an attractive result was achieved. The patient actually requested a copy of the radiograph to show friends and family. I’m looking forward to sharing more cases and am happy to entertain questions/comments. Until next month…


“Living on Tulsa Time” – Eric Clapton

Welcome to the February case of the month. Just because it’s a short month certainly doesn’t mean that there are fewer interesting cases that make their way into the office. This month features a #30 attached to a young man who was apprehensive about having the RCT completed. Typically this has to do with anxiety about potential discomfort. Nothing new in the world of endodontics, but I wanted to bring in a clinical tip that I use in all cases of hot mandibular molars. If you’re doing some of your own endo (or even on teeth with restorative needs), make sure to cold test the tooth you’re about to treat with a #2 cotton pellet loaded with endo ice (or something similar). You’ll be surprised how often soft tissue anesthesia does NOT correlate with pulpal anesthesia. Getting back to our case, notice how the distal canal is less visible until the last 4-5mm. This can indicate the presence of a bifurcation or a canal that is leaning lingually. On the final PA, you’ll notice that the fill may seem radiographically “short”. However, the electronic apex locator (EAL) was reading the major foramen reproducibly. With the accuracy of EALs far surpassing that of conventional radiography, working length was determined by the former. Based on file molding of initial stainless files, this canal exits to the lingual instead of correlating with the radiographic apex. WaveOne Gold medium was used on the distal canal and WaveOne Gold primary on the mesials. Until next month…

MARCH 2017

“Said woman take it slow, and it’ll work itself out fine. All we need is just a little patience” – Guns N’ Roses

Round 1

Welcome to the March case of the month where, as Axl so wisely noted above, patience was key. The patient was a lovely nonagenarian who had been seen previously by another practitioner to start the RCT, but they ran into difficulty navigating the calcification. When I have a case such as this, I make sure to explain the potential pitfalls that may be encountered. Whether it’s needing more than a single visit or even the potential to create a perforation, there’s no such thing as too much information. Ask yourself what you’d want to know about the procedure and make sure you deliver that knowledge in a way that is easily comprehended. I informed my patient that I would do my best to wrap things up efficiently, but quality outweighed speed. I was able to locate, clean, and shape distal and ML at the first visit. MB, however, had other ideas. Calcium hydroxide was placed and a second visit was scheduled.

“shed a tear cause I’m missing you, I’m still alright to smile” – G’N’R

Round 2

Thanks, Axl. Using ProUltra Sine tips (#5 & #6), the calcified orifice of the MB canal came into view early in the second visit. After hand filing, a Vortex Blue 15/.04 and WaveOne Gold Primary accomplished the mission. Clues such as color change and laws of symmetry are key here. These cases demand your absolute focus and attention. They can be incredibly challenging, but there a few greater rewards in endodontics than locating canals such as these. It ensures the best possible prognosis moving forward and you get a small “W” over Mother Nature, if at least for one day.

april 2017

“There’s something happening here, what it is ain’t exactly clear” – Buffalo Springfield

Welcome to the April case of the month where we’re going to get away from instrumentation, curvature, etc. and focus on diagnosis. One of my favorite instructors in dental school always used to say, “you get one”. As in, 1 restoration, 1 RCT or 1 EXT. If there’s no resolution of the chief complaint after any of those stages of treatment, STOP. Reassess what is going on and make sure you haven’t locked yourself into tunnel vision. I tend to see a fair amount of this in my practice where any sort of apical radiolucency is assumed to be endodontic in nature. In reality, that’s not the case. I don’t mind that those patients get referred to me, as it’s my job as an endodontist to conduct a thorough evaluation of the tooth to find the underlying cause. Here’s a great example of someone who presented recently, and unfortunately, had received more than “the one” my instructor described. The patient had neurofibromatosis and was managing her condition. 72% to 92% of all these patients may have oral manifestations. In this case, she had multiple apical radiolucencies in various areas. 3 of these teeth had already been treated endodontically prior to my seeing her, 2 of which were “virgin” teeth and treated on the basis of radiographic appearance alone. The patient had then neglected to have the final restoration completed since she was so concerned about the state of her oral condition. She was referred by an office where she was a new patient with a note to evaluate all teeth with radiolucencies. Fair enough. Here’s where the basic diagnostics come into play. A simple cold test yielded a result of responsive without lingering on all teeth that were tested. Immediately, it should become obvious that the apical changes seen on the radiograph are not endodontic in nature and do not need to be treated. As for the two teeth which had already been treated, the gutta-percha had been exposed for over a year and they are slated for retreatment, pending restorability on #29. This is a situation where this patient could’ve easily received multiple more RCT’s for no valid reason just based on the radiographic appearance. Take the time, perform the diagnostics and get an answer before diving in.

“I think it’s time we stop, hey, what’s that sound everybody look what’s going down”

#29 will need retreatment, pending restorability check

#27 will need retreatment as the gutta-percha was exposed for over one year

#20-22 all tested vital (responsive/non-lingering) to cold.

#25, 26 – Responsive/non-lingering to cold.

May 2017

“It’s it. What is it?” – EPIC: Faith No More

Ah, Faith No More…remember those guys? Lead singer with the hair whipping around and the fish at the end of the video. You remember? If not, Google it and grab yourself some 90’s rock love. Why do I bring them up? Well, in the May case of the month we’ll deal with the all-too-common conversation about internal v. external resorption. In this case, we’re dealing with a very significant (and unfortunately non-restorable) external resorption case. These cases typically start out small and can appear similar to caries upon first glance. As the lesion progresses, more dentin is lost with a small layer of predentin protecting the pulp. Even in a case such as this, patients are typically asymptomatic. There is a classification for types of resorptive defects known as the Heithersay classification, which scores defects from 1-4. Types 1 & 2 are typically treatable, while 3 & 4 are not. This is certainly a 3 at minimum and possible a 4. The external variant of resorptive defects has more of a tendency to reoccur so even with proper endodontic treatment, the process may continue. To address something like this properly, the defect must be circumscribed similar to caries on the occlusal surface. In this case, you can see how much bone would need to be removed to make it happen. One clue to distinguish internal from external is the outline of the chamber and canals. If you can see them clearly, it’s external. There are typically ragged edges as well as opposed to the smooth borders of an internal lesion. When detected early, these cases have a very favorable prognosis. But due to the lack of symptoms and sometime aggressive behavior of the lesion, they can go undetected until it’s too late. Acquiring a CBCT image of these defects is recommended as many of them appear much larger in 3D in contrast with what is seen on a traditional radiograph. When in doubt, it’s better get a consultation to rule it out so that it doesn’t turn into a non-restorable situation.

June 2017

Someday love will find you
Break those chains that bind you
One night will remind you
How we touched
And went our separate ways
Separate Ways – Journey

Ok, so maybe there are no chains or even night time here but, these canals most certainly went their separate ways. I wanted to use the June case of the month to discuss basic anatomy and what to watch out for. Firstly, it’s important to know the difference between the multiple types of classifications out there regarding canal anatomy. Of the many, the Weine and Vertucci types are most prevalent. It’s something you start with in residency and literally commit these numbers to memory. The Weine classification may be a bit of an oversimplification, especially given CBCT technology, but it will give you a basic idea of what to look out for.

Let’s delve a little further into the different tooth types and what to expect with regard to mandibular premolars and molars.

Tooth Type

# of canals

Weine Type

Average Length



1st Premolar

1 (75%), 2 (24%) or 3 (1%)

I / II / III / IV

21.5 mm

Look for “Fast Break” / Possible “C” shape (up to 14%)


2 nd Premolar

1 (98%) or 2 (2%)

I / II / IV

22.0 mm

Watch for mental foramen


1 st Molar

2(7%), 3(64%), 4 (29%) or rarely 5


21.0 mm

“Danger zone” on mesial root furcal area – careful with large Gates / Gain straight line access


2 nd Molar

1(1%), 2(4%), 3(81%), 4(11%)

I / II / III or C-shaped

20.0 mm

“C” shape (3-8%)/ Ribbon shaped distal canal seen / Most susceptible to root fracture


As you can see, mandibular 1st molars should be expected to have 4 canals almost 30% of the time.  Typically, it’s a second canal on the distal.  There’s also a higher prevalence of middle mesial canals as well.  In the case below, it’s not readily apparent that there is a fourth distal canal.  Working through the microscope allowed me to identify that branch and clean it.  Although the large lesions lowers the prognosis slightly, my expectation is to have signs of healing at 1 year, if not complete healing.  The bottom line is to know some of these numbers if you’re treating your own cases and adopt the attitude that these teeth are “guilty until proven innocent”, that is go in thinking that there’s 4 canals until you’re absolutely sure there’s less than that.

July 2017

“Owner of a lonely heart
Owner of a lonely heart
(Much better than a)
Owner of a broken heart
Owner of a lonely heart”
– Yes

Yeah, you can hear the opening guitar riff and there’s the great 80’s synthesizer sounds in the background. Not to mention the video, good stuff. As soon as we took the final PA, I thought of this song when I saw the heart-shaped anatomy. Perhaps in this case they were right about a lonely heart being better than a broken heart. This case had the major potential to wreak havoc with an instrument given the severe nature of the curvature and often times it’s something that can’t be fully appreciated in a conventional PA radiograph. If it’s not instantly visible, but you get a feel for the curvature from a tactile sense take advice from those clues and resist the temptation to move apically too quickly. Establishment of a reproducible glide path is critical. This case was managed with a WaveOne Gold Glider (aka WaveGlider) and WaveOne Gold primary files and 4 canals were cleaned & shaped without complications. If you haven’t had a chance to work with a WaveGlider yet, do so. As always, there’s no one system that will solve all cases, but these two instruments truly make instrumentation more predictable.
Until next month…

September 2017

“You got fins to the left, fins to the right and you’re the only bait in town”

-Jimmy Buffet

 Absolutely my favorite artist of all time (Jimmy, if you happen to be reading this page, I’ve been to 29 of your shows and I’ll see you in Minneapolis with the Eagles in June), Jimmy has provided some quality tunes & lyrics over the years.  When I saw the initial PA, I knew we had a challenge on our hands.  The note from the referral slip literally said, “Have fun, LOL!”.  Thanks, I will.  The WaveGlider from Dentsply Sirona is a newer file out there in the market and really helps to manage a case like this.  Hand file control is still a very important aspect, but once I reach a loose 10, I’m on my way to a WaveGlider.  Once length was reached, we switched over to a WaveOne Gold primary and the canals were cleaned & shaped appropriately.  The complete file listing goes like this; ProTaper Gold Sx, hand file (6-10) to WL, WaveGlider, WaveOne Gold.  I couldn’t have been happier with the post-op and it was nice to know we had cleaned to length, especially with a lesion present.  As for the Buffett tie in…you’ve got fins to the left and fins to the right and the canals are the cleanest in town.  Make sure to watch out for the sharks that can swim on the land

Until next month…

October 2017

Under Pressure, Dancing in the Street, Hunger Strike, Walk This Way

What’s the common thread among the song titles listed above?  If you said “great collaborations”, give yourself a pat on the back.  I’d like to highlight a case this month where we worked with our wonderful neighbor periodontist, Dr. Ryan Harbertson.  The tooth in reference featured a large external resorptive defect that perforated into the canal of #11.  To successfully treat this tooth, the defect itself would have to be restored and RCT would be needed.  This raised the question involving order of operations since there was a concern about irrigants leaking out through the resorptive defect prior to its restoration if we completed the RCT first.  If the resorptive defect were to be restored first, how would we ensure that the canal was not inadvertently obturated with Geristore?  Ultimately, we debrided the canal with EDTA and chlorhexidine and loosely placed a gutta-percha cone in the canal to hold the space.  The patient went next door to the periodontist immediately afterwards and the resorptive defect was repaired.  (Full disclosure, I’m sure some of you are wondering why I didn’t repair the defect.  Not a fan of palatal reflection.  Just a personal preference).  Once the surrounding tissue was healed, I went back in and completed a thorough cleaning & shaping with proper irrigants now that the defect was closed.  You can see the collaborative effort in the final PA.  As Ringo once said, “I get by with a little help from my friends”.

Until next month…