Clinical evaluation of the efficacy of EDTA solution as an endodontic irrigant.

The effect of eliminating the smear layer by means of 15% EDTA solution as a root canal irrigant was studied in 189 single-rooted infected teeth. Each tooth was treated at two appointments, and the root canal bacteriological examination was studied on the first (pretreatment, and after enlargement and irrigation) and second (pretreatment) visits. The root canals were irrigated with 15% EDTA solution with ultrasonics agitation. No antibacterial intracanal medications were used between the appointment. When 15% EDTA solution was used, no bacteria could be recovered from 93 of 129 root canals at the sampling stage on second visit. No bacteria were found in 21 of 60 root canals when saline solution was used as an irrigant. These results suggest that 15% EDTA solution is more effective than saline solution as a root canal irrigant.