Fatigue behavior of sintered, glazed and glass-infiltrated surfaces of 5Y-PSZ bonded plates

Abstract

This study evaluated the effect of different occlusal surface finishes (glaze and silica glass infiltration) on surface characteristics and fatigue behavior of partially stabilized zirconia (PSZ) plates adhesively bonded onto epoxy resin discs. PSZ disc specimens (n = 15; Katana blocks STML, Kuraray Noritake Dental) were produced (Ø = 10 mm; thickness = 1.2 mm) and allocated into 3 groups: As sintered (S), silica glass infiltration (SGI), and glaze application (G). The PSZ intaglio surface was air-abraded with 50-μm alumina powder followed by bonding agent application. All produced PSZ were adhesively cemented onto dentin analogue discs made of epoxy resin material (Ø = 10 mm; thickness = 2 mm). Step stress fatigue test was performed (load ranging from 200 to 1800 N; step size 100 N and 10,000 cycles; 20 Hz). The topographic, microstructural, and fractographic analyses were performed by scanning electron microscopy. Results: No statistically significant difference in fatigue behavior was detected among the groups. All failures started at the bonding surface. Silica glass-infiltration and glaze layer application provided a smoothing effect, while the sintered group had a surface with grooves. The occlusal surface finishing method (silica glass infiltration or glazing) had no deleterious effect on fatigue behavior of adhesively bonded PSZ plates.