Fatigue limit of polycrystalline zirconium oxide ceramics: Effect of grinding and low-temperature aging. (August 2016)

• Record Type: Journal Article
• Authors: Pereira, G.K.R.; Silvestri, T.; Amaral, M.; Rippe, M.P.; Kleverlaan, C.J.; Valandro, L.F.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 61(2016)
• Page Start: 45
• Page End: 54
• Publication Date: 2016-08
• Subjects: Fatigue -- Mechanical cycling -- Grinding -- Low-temperature degradation -- Zirconium oxide partially stabilized by yttrium; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2016.01.006
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: The following study aimed to evaluate the effect of grinding and low-temperature aging on the fatigue limit of Y-TZP ceramics for frameworks and monolithic restorations. Disc specimens from each ceramic material, Lava Frame (3M ESPE) and Zirlux FC (Ivoclar Vivadent) were manufactured according toISO:6872-2008 and assigned in accordance with two factors: (1) "surface treatment"-without treatment (as-sintered, Ctrl), grinding with coarse diamond bur (181 µm; Grinding); and (2) "low-temperature aging (LTD)" – presence and absence. Grinding was performed using a contra-angle handpiece under constant water-cooling. LTD was simulated in an autoclave at 134 °C under 2-bar pressure for 20 h. Mean flexural fatigue limits (20, 000 cycles) were determined under sinusoidal loading using stair case approach. For Lava ceramic, it was observed a statistical increase after grinding procedure and different behavior after LTD stimuli (Ctrl<Grinding; Ctrl<Ctrl Ltd; Grinding=Grinding Ltd); while for Zirlux, grinding and low-temperature aging promoted a statistical increase in the fatigue limit (Ctrl<Grinding; Ctrl<Ctrl Ltd; Grinding<Grinding Ltd). An important increase was observed in m-phase content after both stimuli (grinding and LTD), although with different intensities. Additionally, fatigue test did not promote increase of m-phase content. Thus, tested grinding and low temperature aging did not damage the fatigue limit values significantly for both materials evaluated, even though those conditions promoted increase in m-phase.