19 June 2019

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Root canal irrigation: an update

Massimo Gagliani

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The success of endodontic treatment derives from the complete elimination of microorganisms in intraradicular compartment. To achieve a more effective eradication of these microorganisms, endodontic instrumentation must always be implemented with abundant irrigation, which has to achieve chemical, mechanical and biological effects.  
The irrigation solutions most used today are:

• Sodium Hypochloride (NaOCl) in different concentrations; 
• Clorhexidine (CHX);
• EDTA or other chelating agents like Maleic Acid (MA); 
• Specific antibacterial agent (QMix, Tetraclean); 
• A special use of Calcium Hydroxide (CaOH) in inter-appointment phase; 
• Canphorated paramonochlorophenol (CPMC) associated to CaOH.

These liquid solutions should be released into the root canals through syringes and needles but different techniques, such as manual agitation by guttapecha cone, positive or negative apical pressure, sonic or ultrasonic activation, or laser activations like PIPS and PDT.  

The objective of this review was to update the different irrigating solutions and intracanal disinfection drugs, as well as to establish an irrigation protocol in the endodontic treatment.  

MATERIALS AND METHODS
Systematic search of scientific articles in the databases PubMed, Medline and Google Scholar, with the following keywords Endodontic, Infection, Failure, Irrigation, Retreatment and Irrigation protocol. The exclusion criteria were "case report" articles and articles with a publication date prior to 2000.  

RESULTS 
48 articles that met the inclusion criteria were analyzed. Comparing the different articles it can be seen that the NaOCl was still the "gold standard" in terms of immediate antimicrobial efficacy, followed by the CHX that has a long-term antibacterial effect but should be used particularly on retreatement. As an intra-conductive drug it is advisable to use the combination of Ca(OH)2 with CPMC.

CONCLUSIONS
The most adequate irrigation protocol consists of using a concentration superior to 2.5% NaOCl, activated by ultrasound, followed by a final wash with a final wash of a chelating agent (7% MA or EDTA), a cautious use of 2% CHX, due to its interaction with NaOCl, might be after the root canal has been completely dried by paper points.

(Photo Credit: Dr. Riccardo Tonini)

For additional informations: 
Update of the therapeutic planning of irrigation and intracanal medication in root canal treatment. A literature review.