2TheApex:   Sodium hypochlorite

An ideal endodontic irrigant disinfects the canal, act as a lubricant, removes debris, dissolves tissue, removes the smear layer, and is safe for the patient. Although there is no perfect irrigating solution, one does stand head and shoulders above the rest: sodium hypchlorite (NaOCl). In a review article of irrigating solutions, Haapasallo stated "It is difficult to imagine successful irrigation of the root canal without hypochlorite." Sodium hypochlorite cannot fill all the criteria by itself, and so a chelating such as EDTA is used to help facilitate smear layer removal, but no other irrigant fits the criteria of an ideal irrigating solution better. There are risks to using sodium hypchlorite, and it must be used with caution to avoid extrusion into periapical tissues. Other irrigating solutions have been shown to be potentially beneficial in some circumstances, but if possible they should be used as an adjunct and not as the only irrigant. At this point in time, the research is clear that NaOCl is the best endodontic irrigating solution available.