Influence of ethylenediaminetetraacetic acid irrigation on the regenerative endodontic procedure in an immature rat molar model

Aim To analyse the influence of ethylenediaminetetraacetic acid (EDTA) on the repair process in immature rat molars after a regenerative endodontic procedure (REP). Methodology The lower first molars of 12 4‐week‐old Wistar rats underwent pulpectomy in the mesial root and were divided into the following groups: sodium hypochlorite (NaOCl; n = 6) – the mesial canals were irrigated with 2.5% NaOCl for 5 min, and NaOCl‐EDTA (n = 6) – the canals were irrigated with 2.5% NaOCl, followed by 17% EDTA for 5 min each. After evoking bleeding using a size 10 K‐file, the cavities were sealed. Three molars on the untreated side were randomly used as control (control‐15 d; n = 3), and three molars from the other three rats untreated were used as immediate control (n = 3). After 15 days (NaOCl, NaOCl‐EDTA and control‐15 d groups) or immediately (control‐immediate), the animals were euthanized, and the teeth were subjected to histologic evaluation of tissue regeneration and presence of collagen fibres. Mann–Whitney U‐test was used (p .05). Newly formed connective tissue in the pulp space was significantly higher in the NaOCl‐EDTA group than in NaOCl group (p .05). Conclusions Ethylenediaminetetraacetic acid irrigation improved newly formed intracanal connective tissue after REP in immature molars of rats; however, EDTA did not influence cementum‐like tissue formation, apical closure, inflammatory infiltrate and maturation of collagen fibres.