Ballal NV, et al. - Via this randomized controlled double-blind single-centre trial, researchers investigated if the clinical efficacy of NaOCl alters with the addition of Dual Rinse HEDP, an etidronate, that can be combined with NaOCl to create an endodontic irrigating solution containing both hypochlorite and a chelator in the form of 1-hydroxyethane 1,1-diphosphonic acid (HEDP). Comparison of a pure NaOCl solution vs HEDP-containing counterpart was done regarding antimicrobial efficacy, postoperative pain, and the host response by means of changes in MMP-9 levels in periapical fluid. Outcomes revealed that HEDP had no influence on clinical NaOCl effects.