Irrigation: You Can Clean What You Can’t See

Endodontic irrigation is the second leg of chemo-mechanical cleaning and shaping of the root canal system (RCS).  Both mechanical shaping of the canals and chemical disinfection of the shaped canals are critical to a successful endodontic protocol and a comfortable patient outcome.  Mechanical shaping of the canals was described by Dr. Herbert Schilder in his classic 1974 Dental Clinics of North America article “Cleaning and Shaping of the Root Canal System”.  Fulfilling the five objectives he outlined, provides the necessary space to allow our irrigants to reach all areas of the extremely complex anatomy of human teeth.

The literature is replete with articles on irrigation: the type of irrigant; the amount of time the irrigant needs to work in the canal, the irrigant delivery systems, and the efficacy of the various irrigants and protocols.

The many thousands of articles agree on one thing.  Sodium hypochlorite (NaOCl) is the best irrigant we have today.  All other irrigants are compared to it and none surpass it.  It’s cheap and effective.  It comes as a 6% solution and can be purchased in any store.  It works because it breaks down organic material including bacteria and their pathogenic components such as cell walls and breakdown debris.

The important thing to understand is that as the NaOCl works on that organic material it releases oxygen (the bubbling action you see) and with time its ability to breakdown the organics is depleted.  That means you need to replenish it with fresh NaOCl frequently.  It’s cheap so use a lot.

Many articles focus on the delivery system and how to effectively deliver the NaOCl to all areas of the RCS.  Typically, one uses a syringe of some sort with a needle to deliver the irrigant into the depths of the canal.  To prevent sodium hypochlorite getting outside the RCS which might cause damage to the surrounding normal bone and soft tissues of the jaws needle tips which have side vents were created to direct the NaOCl to the side of the canal rather apically where it might enter the soft tissue.  While they work, these tips are often easily distorted and expensive, and for me, allows the ejection port of the needle to get uncomfortably close to the root terminus and whatever unseen and unanticipated exit points that may be present in the root walls.

My protocol for irrigation is somewhat different.  I like to use a large, 10 ml syringe with full strength NaOCl.  I take a large 22 gauge needle and remove the sharp beveled end (see pictures below).  I keep the pulp chamber full of fresh solution with frequent irrigation but I do not put the tip into the canal proper nor try to take the tip down near the root apex.  This prevents any possibility of extruding NaOCl past the apical terminus of the root and into the surrounding tissue.  The mechanical action of our instruments, both hand and rotary, will carry fresh irrigant to the apex of the canal to effectively and safely remove all the organic pulpal remnants and disinfect the canal.








On December 7, 2016, posted in: News for Doctors by