Soram Oh
This study aimed to evaluate the micro-shear bond strength (μSBS) of TheraCal PT (TP), Endocem MTA Premixed Heavy (EC), One-Fil Putty (OF), and BC Universal RRM (RM) bonded to a flowable composite resin using two universal adhesives (G-Premio Bond or Prime & Bond Universal) in two etching modes (etch-and-rinse or self-etch). Disc-shaped specimens (n = 60 per pulp capping material) were allowed to set for 72 h and then divided into four groups according to the adhesive and etching mode used. The μSBS was measured using a universal testing machine. Data were analyzed with three-way ANOVA and post hoc tests for the pulp capping material. Failure modes were determined. Spectra were recorded before and after adhesive application using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Three-way ANOVA revealed that the effects of the adhesive (p = 0.002), etching mode (p < 0.001), and pulp capping material (p < 0.001) on the μSBS were significant. The interaction between the adhesive and etching mode, as well as the interaction between the adhesive and pulp capping material, was significant (p < 0.001). TP exhibited higher μSBS values than EC, OF, and RM. TP failed in mixed, cohesive, and adhesive modes, whereas EC, OF, and RM failed mostly cohesively within the material. ATR-FTIR spectroscopy confirmed the functional monomer peaks on the material surfaces after adhesive application.