Impact of Final Irrigation Protocol on the Push-Out Bond Strength of Two Types of Endodontic Sealers

Aim: The aim of this study was to assess the impact of the final irrigation protocol on the push-out bond strength of calcium silicate-based sealers when compared to an epoxy resin-based sealer. Materials and Methods: Eighty-four single-rooted mandibular human premolars were shaped using the R25(®) instrument (Reciproc, VDW, Munich, Germany) and then divided into three subgroups of 28 roots each depending on the final irrigation protocol: EDTA (ethylene diamine tetra acetic acid) and NaOCl activation, Dual Rinse(®) HEDP (1-hydroxyethane 1,1-diphosphonate) activation or sodium hypochlorite (NaOCl) activation. Then, each subgroup was divided into two groups (14 each) according to the sealer used (AH Plus Jet(®) or Total Fill BC Sealer(®)) for single-cone obturation. Dislodgement resistance using a universal testing machine, samples’ push-out bond strength and failure mode under magnification were determined. Results: EDTA/Total Fill BC Sealer(®) showed significantly greater values of push-out bond strength compared with HEDP/Total Fill BC Sealer(®) and NaOCl/AH Plus Jet(®), with no statistical difference with EDTA/AH Plus Jet(®), HEDP/AH Plus Jet(®) and NaOCl/Total Fill BC Sealer(®), whereas HEDP/Total Fill BC Sealer(®) showed significantly lower values of push-out bond strength. The apical third demonstrated higher means of push-out bond strength compared with middle and apical thirds. The most common failure mode was cohesive but showed no statistical difference compared to other types. Conclusions: Irrigation solution and final irrigation protocol affect the adhesion of calcium silicate-based sealers.