Effect of simulated gastric acid on the interface between zirconia and resin cement

Purpose: To evaluate the effect of simulated gastric acid solution (SGAS) and resin cement composition on the shear bond strength (SBS) between zirconia-based materials with different levels of translucency and composite resin. Materials and Methods: A total of 40 medium-opacity (MO; 3Y-TZP) and 40 medium-translucency (MT; 4Y-PSZ) zirconia slabs were distributed into four groups according to the composition of the resin luting system (MDP [methacryoxydecyl dihydrogen phosphate]–free or with MDP [Primer + PANAVIA V5]) and storage method (distilled water or SGAS [5% hydrochloric acid]). Composite resin cylinders were cemented on the zirconia surface and stored for 91 hours. SBS, failure mode, and surface characterization via scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were performed. SBS data were analyzed by three-way ANOVA and Tukey honest significant difference test, and failure mode was assessed using one-way ANOVA ( P < .05). Results: Storage media ( P = .180), resin cement ( P = .110), zirconia ( P = .404), and their the interactions did not affect SBS values. Bond strength ranged from 21.41 to 26.11 MPa. SEM images showed that SGAS modified the surface topography of zirconia and resin cement. The presence of Cl and Si (wt %) were higher after SGAS storage than after water storage in both cements used, while Ba was higher only for the cement with MDP. There was a prevalence of mixed failures for most of the groups. Conclusion: SBS between both types of zirconia and resin cement was not affected by SGAS, although changes in zirconia topography were observed after SGAS exposure. The presence of MDP in the cement layer had no effect on the SBS challenged by SGAS. Int J Prosthodont 2022. doi