Thirty-two full contour Y-TZP (Diazir®) specimens (hereafter referred to as zirconia sliders) (ϕ = 2 mm, 1.5 mm in height) were fabricated
using CAD/CAM and sintered according to the manufacturer’s instructions. Zirconia sliders were embedded in brass holders using acrylic resin and then randomly assigned (n = 16) according to the surface treatment received, that is, as-machined or glazed. Glass-ceramic antagonists, Empress/EMP and e.max/EX, were cut into tabs (13 × 13 × 2 mm3), wet-finished, and similarly embedded in brass holders. Two-body pin-on-disk wear testing was performed at 1.2 Hz for 25,000 cycles under a 3 kg load. Noncontact profilometry was used to measure antagonist height (μm) and volume loss (mm3). Qualitative data of the Sirolimus mouse zirconia testing surfaces and wear tracks were obtained using SEM. Statistics ICG-001 price were performed using ANOVA with a significance level of 0.05. As-machined yielded significantly higher mean roughness values (Ra = 0.83 μm, Rq = 1.09 μm) than glazed zirconia
(Ra = 0.53 μm, Rq = 0.78 μm). Regarding glass-ceramic antagonist loss, as-machined zirconia caused significantly less mean height and volume loss (68.4 μm, 7.6 mm3) for EMP than the glazed group (84.9 μm, 9.9 mm3), while no significant differences were found for EX. Moreover, EMP showed significantly lower mean height and volume loss than EX (p < 0.0001). SEM revealed differences on wear characteristics between the glass-ceramics tested. e.max wear was not affected by zirconia surface roughness; however, Empress wear was greater when opposing
glazed zirconia. Overall, surface glazing on full-contour zirconia did not minimize glass-ceramic wear when compared with as-machined zirconia. “
“This study evaluated the fatigue behavior of three fixed partial dentures (FPDs) before and after artificial fatigue testing. Sixty, three-unit zirconia-ceramic (ZC), galvano-ceramic (GC), and porcelain-fused-to-metal (PFM) FPDs (N = 20) were fabricated. Ten specimens from each group were exposed to fatigue testing by being thermocycled (5 to 55°C, 10,000 cycles) and loaded (100,000 cycles, 50 N, 0.5 Hz). All specimens were then subjected to occlusal loading in a universal testing machine until fracture. selleck chemicals The fractures were characterized using scanning electron microscopy. Data were analyzed using one-way ANOVA followed by Tukey’s significant difference post hoc test and the paired t-test. The chi-squared test was used to evaluate the type of fracture (α = 0.05). The mean fracture loads of non-fatigued and fatigued specimens for ZC were 2434.9 ± 154.3 and 2333.1 ± 183.0 N, respectively; for GC were 1678.1 ± 211.6 and 1475.8 ± 227.9 N, respectively; and 1878.5 ± 176.5 and 1687.8 ± 162.2 N, respectively, for PFM restorations. Significant differences were observed between fatigued and non-fatigued specimens of both the GC group and PFM group (p < 0.05), but not between fatigued and non-fatigued ZC specimens (p > 0.05).