Dear sir

I have been reading with interest the articles on Modern Endodontic Principles. In the article in the April issue (Managing Complex Situations) it states that chlorhexidine irrigation in retreatment cases has been shown to have a negative effect. I seem to remember reading in a paper in Update some years ago by Good, El Karim and Hussey that chlorhexidine had a place in retreatment cases as it was effective against Enterococcus faecalis, a known pathogen in this situation. Consequently, I have been using it instead of NaOCl since then. As a general practitioner it is difficult to know what to do. Clarification would be greatly appreciated.