The Mechanical Footprint of Dual Rinse 1-Hydroxyethane 1,1-Diphosphonate on Fast-Set Mineral Trioxide Aggregate...

This study evaluated the effects of various root canal irrigation protocols on the surface microhardness and push-out bond strength of a fast-set hydraulic calcium silicate-based cement at two different stages of hydration.

Standardized 3-mm-thick root slices with uniform lumens were filled with RetroMTA (BioMTA, Seoul, Korea). The slices were randomly assigned to two setting intervals (1 or 14 days), after which their upper surfaces were irrigated using one of several protocols, including 2% NaOCl, 5.25% NaOCl, Dual Rinse HEDP mixed with either 2% or 5.25% NaOCl, 2% or 5.25% NaOCl followed by EDTA, or normal saline (as a control). The dislocation resistance of RetroMTA was then measured using the push-out bond strength test. For surface microhardness assessment, RetroMTA-filled polymethyl methacrylate molds were exposed to the same irrigation protocols, and their surface microhardness was measured using the Vickers microhardness test. The data were analyzed using one-way and three-way ANOVA tests.

One-way ANOVA showed that neither the 1-day nor the 14-day RetroMTA groups differed significantly from the control group in push-out bond strength or surface microhardness (p > 0.05). Three-way ANOVA demonstrated that no two-way or three-way interaction effects were statistically significant. Moreover, NaOCl concentration, chelator type, and the time interval between RetroMTA placement and irrigation had no significant effects on push-out bond strength or surface microhardness (p > 0.05).

Under the limitations of this experimental study, no significant differences were detected among the effects of Dual Rinse HEDP mixed with either 2% or 5.25% NaOCl, NaOCl alone, or NaOCl followed by 17% EDTA on the push-out bond strength or surface microhardness of 1-day and 14-day RetroMTA samples.