Endodontic spotlight: negative pressure irrigation
Success in endodontic therapy relies on the ability to effectively remove debris and bacteria from the canal system via irrigation.
Traditionally, positive pressure with a syringe or irrigation needle has been the technique for cleansing and sterilizing the canal. However, bacteria can remain in the final apical third, creating the need for an alternate irrigation technique.
In this post, we’ll cover the potential issues with positive pressure irrigation and how negative pressure irrigation can lead to more predictable results.
Reliant on operator control
Manual control of irrigant flow with a syringe relies on the dentist’s ability to place the irrigation needle in the correct place and apply a precise amount of force.
- If too much force is applied, the irrigant can extrude from the periapical tissue. Sodium hypochlorite (NaOCI), a preferred irrigant, can cause significant discomfort to periradicular tissue when extrusion takes place.
- If not enough force is applied, the apical third will not be properly cleaned, leaving debris and bacteria inside.
Reliance on operator control makes it difficult to standardize the technique.
Positive pressure irrigation
A tool such as the EndoVac draws irrigant released into the pulp chamber all the way to the apical foramen and back. The EndoVac clears the entire canal without risk of forcing irrigants into the periapical tissue. Such a tool removes almost all human error from the equation, providing consistent and reliable performance.
Negative pressure irrigation works with the cooperation of two parts: the delivery tip and the cannula. Two different sized cannula are applied to remove the irrigant:
- The MacroCannula eliminates coarse debris from the canal
- The MicroCannula uses a dozen microscopic (less than 100 micron) evacuation holes through a 28-gauge needle to create a cleaning vortex in the apical third.
More irrigant, less hypochlorite accident
By suctioning out irrigant before it has the potential to extrude from the periapical tissue, negative pressure irrigation offers the added benefit of being able to use more irrigant with a much lower risk of extrusion. A greater volume of irrigant, reaching the full length of the canal, leads to better chemical debridement of bacteria and a fully disinfected root canal system.