Purpose: To evaluate the effect of QMix and other conventional endodontic irrigants on the micropush-out bond strength of Biodentine (BD) and white mineral trioxide aggregate (WMTA).
Materials and Methods: One hundred eighty midroot dentin slices with a thickness of 1.0 mm were prepared. BD and WMTA were placed inside the lumens of the root slices (n = 90). Then the specimens of each material were divided into 6 groups (n = 15) according to irrigation solution (saline, 5.25% NaOCl, 2% CHX, 17% EDTA, or QMix) immersed in the same for 30 min. For the control group, a wet cotton pellet was placed over the specimen. After that, the micropush-out bond strength was determined using a universal testing machine, and the bond failure mode was determined using a stereomicroscope. The morphological microstructures of specimens were evaluated with scanning electron microscopy (SEM). Data were analyzed using ANOVA and Tukeys post-hoc test.
Results: BD revealed higher bond strength than WMTA (p < 0.05). WMTA was significantly affected after exposure to 2% CHX solution. QMix irrigant did not compromise the bond strength of BD or WMTA. Most failures for BD were cohesive, while for WMTA, adhesive failures were the predominant type. A substantial change in the microstructure of BD and WMTA occurred after exposure to different irrigation solutions.
Conclusions: QMix did not affect the bond strength of BD or WMTA. BD showed higher resistance than WMTA to dislodgement forces from root dentin.
Keywords: Biodentine, white mineral trioxide aggregate, micropush-out, perforation repair, QMix