Tag Archives: Root canal

Beware of the Cracks!

Imagine the following scenario:

A busy day in practice! A patient comes in with tooth #2-6 (upper left first maxillary molar) being extremely sensitive to cold (a.k.a. a “hot tooth”).  You notice a very old, large amalgam filling on the tooth which had been done over 2o years ago.  No recent restorative changes in the area  is reported by the patient.  Breathing in air, blowing air on this tooth with an air-water syringe or applying ice to the tooth sends the patient through the roof.  All other teeth in this quadrant are responding normally to cold test. Quickly and confidently, a pulpal diagnosis is reached (irreversible pulpitis), endodontic treatment is recommended, and the need for a full coverage crown is also emphasized after root canal treatment. Simple, right?

cracked tooth, split tooth

pre-op radiograph

 

Well, not so fast!

  • unless you stopped and thought about the reasons why the tooth became sensitive to begin with (i.e. thinking about the etiology for pulpitis and the possible pathways to the pulp),
  • unless you thoroughly examined the tooth clinically and looked for signs of cracks, leakage, caries, periodontal disease, parafunctional habits, etc.,
  • unless you grabbed a perio probe and actually noticed a 6-7mm probing defect on the distal aspect of the tooth,
  • unless you noticed on the pre-op radiograph a questionable area with respect to the quality of the crestal bone between teeth #2-6 and #2-7,
  • unless you removed the obscuring filling and gave yourself an adequate view of what lies beneath during the treatment (as opposed to those who still love to brag about their super conservative access and their beautiful final result through a tiny 2x2mm hole),

This slideshow requires JavaScript.

You may miss a more serious issue with this innocent-looking tooth in need of JUST a root canal and a crown,  you may lose the opportunity to properly inform your patient of possible outcomes of your treatment and you may end up performing unnecessary treatments for a tooth with no hope.

Just imagine the final conversation with the patient after a quick exploratory/pulpectomy procedure:

Me –  “Ms. Black, unfortunately your tooth cannot be saved as I had suspected and warned you before we started the root canal procedure today.”

Ms. Black – “I am amazed Dr. E! [with a smile]  You knew exactly what was wrong with my tooth. You called it.”


Office website: vanendo ,  FaceBook page: @endospecialists


Irrigation…how low do you dare to go?

Irrigating the canals…probably the easiest part of providing root canal treatment, yes?

I think I graduated from dental school years and years ago with a deeply instilled fear of perforation, a reluctance to tackle calcified teeth, and anxiety whenever I waited for my obturation film to emerge from the processor. Irrigating the root canal was the breeziest part of treatment, to my memory. I placed an irrigating tip into the canal, made sure it didn’t bind in any place, it was probably hanging around the coronal or mid-root part of the canal, and I pressed the plunger a few times. Presto! Irrigation done. Right. Right?

Reading up on the irrigation literature these past few years has changed my thinking about the importance of irrigation, and it is a procedure that I spend a lot of time on now, probably equalling instrumentation! Many advocate viewing shaping of the canal with rotary instruments as a means to allow irrigants to effectively reach the most apical portion of the root canal. Many would be surprised to see that if our irrigation needle tips are not placed in the apical third of the root canal, we may not be achieving effective irrigation. The easiest way to show this is through a little home made video here, which shows me irrigating in a plastic canal, with a 30 gauge needle, using a fair amount of pressure, equal to about 5 ml/min. The needle tip is held about 3 or 4 millimeters from the “end” of the root canal. Notice how the exchange of irrigant only extends a small distance beyond the end of the needle tip: 

Based on some of the literature to date, here are a few suggestions for achieving effective irrigation using a conventional irrigation method:

1. Use a flexible, small gauge irrigation needle, for example, a 30 gauge needle or smaller, that is designed with a closed-end and side-vent (for patient safety). I find that it is quite difficult to use an irrigation needle bigger than a 30 gauge needle, unless the root canal is very large.

2. Prepare the root canal to an adequate apical size and taper such that a small gauge irrigation needle can be placed within 1-2 mm of the working length, or at least in the apical third.

3. Use very gentle finger pressure! A high irrigation flow rate (e.g. high finger pressure) is not required; recent research shows that high pressure/high flow rates does not correlate to “better cleaning”.

4. Activate your irrigants! Use of a sonic or passive ultrasonic tool, such as the EndoActivator by Tulsa, or the Irrisafe file by Clinical Research Dental can make your irrigation more effective. There are many options for agitating your irrigants, and I try to “energize” each irrigant that I use for at least 45-60 seconds per canal, per irrigant, after the majority of the cleaning and shaping has been done.

If you like reading journal articles, here is my recent paper on the “theoretical measured pressure” that the periodontal ligament might feel when we are irrigating root canals. We also have a review paper on irrigation of the apical third in the journal Endodontic Topics, have a read. Send us a message if you can’t find it. Park Shen Haapasalo 2013 irrigation JOE


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.

This slideshow requires JavaScript.

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.

This slideshow requires JavaScript.


%d bloggers like this: