EDTA – factual disputes

Sir, I read with great interest the article entitled ‘Modern Endodontic Principles Part 4: Irrigation’ by Darcey J et al, which has been published in your esteemed journal (Dent Update 2016; 43: 20–33). It was a good review article on the basic irrigating agents and devices used in endodontics. I want to share a few of my thoughts regarding this article. The use of ethylenediaminetetraacetic acid (EDTA) mentioned in that article as a root canal irrigant needs to be reconsidered. Even though EDTA is the most frequently used chelator in endodontics, it does not remove the smear layer effectively, especially in the apical third of the root canal system which is the vital area for disinfection.^1,2 In this regard, I would like to mention a novel chelating agent ‘maleic acid’, which has been studied extensively in endodontic literature. Maleic acid (7%) has been shown to remove the smear layer effectively when compared to 17% EDTA and various other chelators, especially in the apical third of the root canal system.^1,2,3 It is also less cytotoxic when compared to 17% EDTA⁴ and has good antimicrobial properties when combined with auxiliary chemicals.⁵ It has been shown to improve the bond strength of resin sealers when compared to 17% EDTA.^6,7,8 It has also been shown to produce increased surface roughness of the root canal walls when compared to EDTA, which might help in effective bonding of the resin-based materials to root canal dentine.⁹ Hence, considering these drawbacks of EDTA, a clinician should rethink its use as a chelator in endodontic therapy.