• Sonza, Queli Nunes
• Bona, Álvaro Della
• Borba, Márcia

Abstract

<p>Objectives: To evaluate the effect of infrastructure (IS) material on the fracture behavior of prosthetic crowns. </p><p>Methods: Restorations were fabricated using a metal die simulating a prepared tooth. Four groups were evaluated: YZ-C, Y-TZP (In-Ceram YZ, Vita) IS produced by CAD-CAM; IZ-C, In-Ceram Zirconia (Vita) IS produced by CAD-CAM; IZ-S, In-Ceram Zirconia (Vita) IS produced by slip-cast; MC, metal IS (control). The IS were veneered with porcelain and resin cemented to fiber-reinforced composite dies. Specimens were loaded in compression to failure using a universal testing machine. The 30° angle load was applied by a spherical piston, in 37°C distilled water. Fractography was performed using stereomicroscope and SEM. Data were statistically analyzed with Anova and Student-Newman-Keuls tests (α = 0.05). </p><p>Results: Significant differences were found between groups (p = 0.022). MC showed the highest mean failure load, statistically similar to YZ-C. There was no statistical difference between YZ-C, IZ-C and IZ-S. MC and YZ-C showed no catastrophic failure. IZ-C and IZ-S showed chipping and catastrophic failures. The fracture behavior is similar to reported clinical failures. </p><p>Significance: Considering the ceramic systems evaluated, YZ-C and MC crowns present greater fracture load and a more favorable failure mode than In-Ceram Zirconia crowns, regardless of the fabrication type (CAD-CAM or slip-cast).</p>

Topics

• impedance spectroscopy
• scanning electron microscopy
• ceramic
• resin
• fracture behavior
• fiber-reinforced composite
• fractography
• collision-induced dissociation