If you are interested in an endodontic refresher lecture, come and join me next Thursday at the Pacific Dental Conference (PDC 2019). Two and a half hours lecture filled with pictures and videos demonstrating the initial endodontic treatment.
The following is an excerpt from #vanendo lecture series at this year’s Pacific Dental Conference.
The apical 3mm of an infected root canal system is considered to be the “Critical Zone” when it comes to the chemomechanical preparation. Mechanical instrumentation and chemical disinfection of the root canal system to its full length significantly affect the outcome of treatment. All endodontists agree that the irrigation phase of the root canal treatment must be accompanied by an agitation technique. These techniques include: sonic agitation (EndoActivator), ultrasonic agitation, multi-sonic agitation (promising area of research currently), and the cheapest and simplest of all, Manual Dynamic Agitation (MDA).
The following video demonstrates how the MDA technique (repeated insertion of a well-fitting gutta-percha cone to the WL at a frequency of 100 strokes/min) significantly facilitates debris removal from the apical portion of a root canal system that appears to be fully shaped and cleaned.
Are you ready for the Pacific Dental Conference 2018 next week?
Come and join me for an overview of the “shaping” and “cleaning” stages of root canal treatment.
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
The dentin mud or “smear layer” forms as a result of the action of endodontic instruments during root canal therapy. The debris (inorganic materials along with the pulpal tissues, bacteria, blood cells, etc.) that is formed is smeared against the canal surface during the cutting and planing actions of the endodontic files and instruments. This layer harbors surviving micro-organisms and interferes with the penetration of irrigation solutions, medication and obturation materials into the dentinal tubules.
Removal of this layer not only allows the irrigants to better penetrate and kill the micro-organisms that have invaded the dentinal tubules, but it also improves the contact and adaptability between the obturation material and the canal walls and ultimately the seal.
The most commonly used endodontic irrigants are: sodium hypochlorite (NaOCl) and EDTA. They effectively remove both organic and inorganic components of the smear layer. Alternate use of NaOCl and EDTA solutions during irrigation provides the most cost-effective method of disinfecting the root canal system.
Other all-in-one irrigation solutions such as BioPure MTAD (Tetracycline, citric acid and a detergent) or QMix (EDTA, CHX and a detergent) have also been shown to be very effective in removing the smear layer and killing the micro-organisms while respecting the dentinal structure.