Bond strength of mineral trioxide aggregate to root dentin after exposure to different irrigation solutions

AimThe aim of the study was to evaluate the regional push-out bond strength of mineral trioxide aggregate (MTA) after exposure to sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), and peracetic acid (PAA) irrigation solutions. Materials and Methods1-mm-thick longitudinal slabs of root dentin were obtained from freshly extracted human canine teeth (n=80). Simulated root perforation defects, 1mm in diameter, were prepared in the coronal, middle, and apical thirds of radicular dentin. Mineral trioxide aggregate was placed into the cavities, and the specimens were stored for 1week at 37 degrees C. Thereafter, the specimens were randomly divided into four groups (n=20) according to the irrigation solution applied over the repair sites: Group 1-10ml of 5.25% NaOCl for 10min; Group 2-10ml of 5.25% NaOCl for 10min, followed by 5ml 17% EDTA for 5min; Group 3-10ml of 5.25% NaOCl for 10min, followed by application of 5ml 1% PAA for 5min; and Group 4-no irrigation. Push-out test was performed at a crosshead speed of 1mm/min. Debonding values were compared statistically using two-way analysis of variance and Tukey tests (P<0.05). ResultsThe push-out bond strength of MTA was not affected by the type of irrigation solution or location of the perforation defects (both P<0.05). Stereomicroscopic inspection of the samples showed that the bond failure was predominantly adhesive. ConclusionExposure of repaired root perforations to 5.25% NaOCl, 17% EDTA, or 1% PAA does not alter the dislocation resistance of MTA at different locations of root dentin.