Irrigants: solutions and techniques
Fig. 1
Fig. 2

Apical delta and lateral canals are cleaned through the action of irrigants.

Irrigants: solutions and techniques
Fig. 3

Needles and syringes for endodontic irrigation have precise characteristics, for efficacy and safety. Open-ended needles are more efficient in irrigant replacement, but create a jet toward the apex, dangerous for extrusion; so they must be kept 3 mm away from apex. Side-vented needles are safer and can be used at 1-2 mm from apex. The needle should be bended at fixed length, e.g. 21, 25 and 28 mm, for easier use, and a silicone stop should be used. Colour-coded needles and syringes are useful for different irrigants. Luer-lock syringe prevents accidental disconnections and spilling.

Irrigants: solutions and techniques
Fig. 4

The efficiency of irrigation can be compromised because of the root canal system complex anatomy, with the lateral canals, isthmuses, ramifications and apical delta. Numerous techniques of active irrigation have been proposed, in order to increase the effectiveness in cleaning the root canal system. Dedicated needles and syringes, brushes or even a guttapercha cone (Manual Dynamic Activation, Caron et al. 2010) can be used manually to improve NaOCl efficacy through mechanical agitation.

Irrigants: solutions and techniques
Fig. 5

A rotary handpiece–attached microbrush has been proven effective in vitro to displace residual debris out of the canal. Continuous irrigation during instrumentation is used by Quantec-E and Self-Adjusting File irrigation system. The EndoVac system is a negative pressure irrigation system, and also RinsEndo uses a pressure-suction system, but with a dedicated disinfectant. The EndoActivator is a sonic device that uses polymer tips to agitate irrigant, while passive ultrasonic irrigation vibrates an endodontic file in the irrigant solution, without simultaneous instrumentation. Irrigants can also be activated through energy delivered by laser.

Fig. 6

Microphotography of a drop of irrigant extruded by an endodontic needle.


The ideal properties of an irrigant solution should be: lubrification, suspension of debris, ability to dissolve organic and inorganic tissues, antibacterical and antimicrobial effect, ability to remove bacterial biofilm and to avoid alteration of dentinal structure. NaOCl 5/7%, associated with a chelating agent like EDTA, is the most used irrigant solution and has a strong effect in reducing bacteria inside the canal and as a solvent for organic tissues, while the chelating agent helps in removing smear layer. Heating of Hypochlorite can enhance its effect. A good irrigation technique is of utmost importance, and it starts with a perfect field isolation, the use of a chelating agent during negotiation, an adequate shaping of the root canals to create space for penetration of the irrigant, sufficient volume of irrigant and time, frequent exchange and activation with one of the methods listed above. A final irrigation protocol should be followed after shaping, this is the one used by the author of this article: NaOCL 5% 45° at working length -2mm, activate, suction, repeated three times; suction, saline solution, then EDTA 17%, and final rinse with ethanol.


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