Endodontic irrigant play an important role in the elimination of
microorganisms from the root canal system, dissolving organic tissue,
removing of debris and the smear layer. Sodium hypo-chlorite (NaOCl) is
a powerful antiseptic agent which dissolves the organic part of dentin,
vital and necrotic tissue and neutralizes toxic products. Its
antibacterial effect increases with increasing concentration. Due to
inadequate surface tension, NaOCl has restricted access to narrow and
accessory canals. Chlorhexidine (CHX) has an antibacterial efficacy
comparable to NaOCl, while being effective against certain NaOCl
resistant bacterial strains. Effective root canal disinfection is
achieved due to substantivity, i.e. continued and prolonged
antimicrobial effect. Unlike NaOCl, it’s not able to dissolve organic
material within the root canal. Ethylene-diamine-tetra-acetate (EDTA)
removes the inorganic part of the dentinal wall facilitating the passage
of endodontic instruments. It doesn’t act on the organic smear layer and
hasn’t antimicrobial properties. It seems that not all irrigants not
able to fulfill all the necessary requirements, so their combined use is
necessary. Studies have shown that there are interactions between some
irrigants, which are undesirable and may compromise endodontic therapy.
A mixture of NaOCl and CHX leads to staining of the teeth and the
creation of an orange-brown precipitate, which either remains in the
dentinal wall or exceeds to the periapical tissues. CHX and EDTA
combination also produces a precipitate. This precipitate reduces
permeability, disruptives hermetic obturation and can act as a chemical
smear layer. It was found that the precipitate consist of the
para-chloroaniline, which has been experimentally shown to have toxic
effects on the tissue around the root apex. Simple adjustments in the
irrigation protocol can prevent the occurrence of adverse reactions
between endodontic irrigants.
Key words: endodontic
irrigants, interactions, precipitate
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Address of correspondence:
Jovanka Z. Gašić, redovni profesor Medicinskog fakulteta u Nišu
Klinika za stomatologiju, Odeljenje za Bolesti zuba i endodonciju,
Bulevar dr Zorana Đinđića 81, Niš, Srbija
E-mail:jgasic@yahoo.com
Copyright © 2014 by The Editorial Council of The Acta Stomatologica Naissi |