Category Archives: Prognosis

How do you “seal” the deal?

After we’ve spent so much time doing great endodontic treatment – with rubber dam isolation, perhaps gingerly applying OraSeal or Kool-Dam to make sure everything is water tight, carefully instrumenting, copiously irrigating, and then obturating with great style – how can we protect our painstaking work?

Here is a case where the root canal has been completed, but unfortunately, the final restoration – a ceramic restoration – has been made without replacing the cotton pellet and temporary base material. Even though the periapical lesion has healed nicely, the risk of coronal leakage, and thus the need for retreatment in the future again, is great.

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One nice way to prevent coronal microleakage is to definitively restore the teeth after root canal treatment. If you want to go one step further, you might consider an intra-orifice barrier. This is simply a (bonded) restoration that involves removing approximately 2 mm of gutta percha from the orifice of the root canal. Then, a material, such as glass ionomer, or composite, or MTA can be placed into the orifice. I also prefer to cover the furcation floor. I have been placing an intra-orifice barrier of glass ionomer (and often a 1 mm intra-canal barrier when I prepare post spaces), and then restoring the rest of the access with a bonded core material when indicated. The glass ionomer can be placed with a small plugger, or a Centrix Accudose needle tube.

I have also been trying a neat product as an intra-orifice barrier, PermaFlo Purple, which is simply a flowable composite that is colored purple. You can place a tooth-colored material on top, in the bulk of the access. I suppose the rationale of a purple-tinted flowable composite is to make any future treatment easier, since you’ll be looking for purple composite, instead of B2 composite! The case below shows a 2 mm intraorifice barrier of glass ionomer, extending below the floor of the root canal chamber.

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Micro-surgery Works, Macro-surgery Doesn’t.

When endodontic surgery (a.k.a. apico, apicoectomy) is indicated, certain steps must be followed in order to ensure a successful outcome.  Skipping any of the steps below, specially steps 4 AND 5, may result in failure:

  1. Proper flap design.
  2. Adequate magnification and use of proper instruments.
  3. Root-end resection: to expose the uncleaned isthmi between the canals and to eliminate portal of exits/apical deltas which are more frequently seen in the apical 2-3mm.
  4. Retro-preparation: to create a class I cavity prep for placement of retro-filling material.
  5. Retro-filling: to seal the canal at the apical end, which is ABSOLUTELY NECESSARY for the apical surgery to be successful. Without this seal, the surgery is bound to fail as the root-end resection (Macro-surgery) alone cannot prevent the bugs from coming out of the canal system and causing the periapical lesion.
  6. Primary flap closure: in order to allow the stabilized clot that forms in the surgical site turning into bone in the absence of micro-organisms.

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Your Tooth Broke My File!

“A dentist who has not separated a tip of a file, reamer, or broach has not done enough root canals.” — Louis Grossman

There are essentially 2 reasons for rotary rotary instrument separation inside a canal:

1) Cyclic fatigue (file rotating inside a curved canal for extended period of time):
Factors contributing to cyclic fatigue are: overuse of rotary NiTi files, spending too much time inside the canal during instrumentation, canal curvature (degree and abruptness of the curvature), improper speed setting for the handpiece and the file tapers (larger tapers break faster).

2) Torsional fatigue (too much friction between the rotary file and the canal wall):
Factors contributing to torsional fatigue are: improper endodontic access, using too much apical pressure during instumentation, not following the proper sequence for a particular file system, not using lubricating agent/irrigants, using greater tapered files inside a tight/calcified canal and using handpieces with no torque control or auto reverse option.

Attempting to control the factors above will greatly minimize the risk of file separation.  But even in a perfect situation, a patient’s canal anatomy can bring the man-made technology to its knees.

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What to do if a file breaks inside a canal?

1. Stay calm. It is not the end of the world.

2. Try to remove it only if the separated portion is in the coronal segment of the tooth and not past the root curvature. This step also requires good magnification, illumination and proper tools (such as different ultrasonic tips).

3. Bypass it if the separated segment is apical to the curvature of the root using hand-instruments and finish the shaping of that canal with hand-files. Sometimes the separated file comes loose and can be easily flushed out.

4. Make it part of the filling if the file has completely blocked the canal. This may not affect the prognosis negatively [Crump and Natkin 1970, Spili et al. 2005] depending on the initial status of the pulp and whether or nor the separation happened towards the beginning or the end of cleaning and shaping stage.

5. Follow up the healing and the resolution of symptoms. Endodontic surgery may be needed if symptoms persist or the PA lesion does not heal.

It is ‘Game Over’!

Vertical root fractures (VRF):

  • are associated with endodontically treated teeth.
  • are commonly directed bucco-lingually.
  • are mostly diagnosed by localized probing defects (+/- sinus tract) that are usually present around the fractured root.
  • show periradicular bone loss that is more pronounced in the middle and cervical 1/3 compared to the apical 1/3
  • are not always detectable clinically (they can happen in the apical, middle or cervical area).
  • are associated with the roots that are curved and are wide buccally and lingually but are narrow mesially and distally.

Etiologies: wedging posts, excessive root-dentin removal (using large tapered files, orifice shapers, gates glidden drills, etc.), obturation forces.

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If vertical root fracture is detected in single-rooted tooth, it’s game over.  In multi-rooted teeth, other options (such as, root amputation or hemisection) can be considered before extraction.

A Hopeless Case?

“In traumatic dental injuries, not only it is important to know when to treat a case (endodontically-speaking); it is equally important to know when not to treat it.” – Martin Trope

Before considering extraction of a tooth with root fracture, no matter how bad it looks on the x-ray, the following treatment approach must be considered in order to give the tooth another chance:

1) reduction: repositioning the tooth back into the socket,

2) fixation: stabilizing the tooth with a flexible splint for four weeks (if the fracture is in the middle or apical third area), or for four months (if the fracture is in the cervical third area),

3) relief of occlusion: to minimize further damage to the PDL and the protective layer of the root, and

4) recall: monitoring clinically and radiographically in 6-8 weeks, 4 months, 6 months, 1 year and yearly for 5 years.

After three months of follow-up, endodontic treatment of only the coronal segment should be considered if the tooth continues to be unresponsive to vitality testing, appears discoloured, and/or develops periapical pathosis (radiolucency) around the fracture line.

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The tooth above has remained asymptomatic and functional 2 years after the endodontic treatment and 3 years after sustaining a traumatic injury. I always remind myself of what Ian Linde would say when considering all options for cases that appear hopeless on the radiograph: “Implants should replace missing teeth not teeth.”

(Resource: The Dental Trauma Guide: your interactive tool to evidenced based trauma treatment.)

Oh No, Vertical Root Fracture!

We have all come across an endodontically-treated tooth with vertical root fracture (VRF). What gives the VRF away is the pattern of bone loss (more bone loss occlusally than apically) and the clinical attachment loss on the buccal or lingual aspects of a specific root. It is also associated with posts inside the canals or use of large size GGs or large-tapered orifice shapers and as a result, weakening of the coronal portion of the canals. Other important findings include: good looking root canals, lack of PA lesions, presence of J-shaped lesion, periodontal probing defect on the buccal or lingual aspects of the root, sinus tract tracing back to the level of fracture and not all the way to the apex.

As soon as vertical root fracture is diagnosed, the prognosis is assumed to be hopeless and extraction and implant become the top choice in the view of the majority of us, dentists. I used to agree with the above statement and never cared for herodontics to save these teeth until I came across quite a few cases with long-term follow-ups that have made me think twice about this.

If I had seen this patient, I would have thought there is no way hemisection would work in this case. To be honest, I may have not even thought about this option in this day and age of implant dentistry. I would have thought to myself that the distal root is very narrow mesiodistally to begin with and has a metal post in it. The distal root would have been the next root to go in my opinion. After all, this is a major chewing tooth with relatively heavy occlusion. A 10-year follow-up of this case shows an absolutely beautiful restorative work with a lone standing root that is still an integral part of this bridge.

I am sure there are so many examples of works like this that have worked out and some that did not stand the test of time. But, I truly believe that every natural tooth deserves a change to survive for as long as possible. Implant is a great option to replace a missing tooth, not a tooth.