Fatigue resistance of extra translucent zirconia

• Grant number: 19/22435-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2020
• End date: June 30, 2021
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Marco Antonio Bottino
• Grantee: Ana Julia Borgia Rodrigues de Oliveira
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Objective: To characterize microstructurally and analyze the fatigue strength of an extra translucent zirconia ceramic. Methodology: Extra translucent zirconia blocks (Vita YZ XT, Vita Zahnfabrik) and high translucent zirconia (Vita YZ HT, Vita Zahnfabrik) will be used. From the CAD-CAM blocks, ceramic discs of 12 mm in diameter and 1.2 mm in thickness will be obtained (n = 25). Microstructure characterization will be performed by scanning electron microscopy (SEM) to visualize the material's grains and their topographic characteristics, energy dispersion spectroscopy (EDS) for the recognition of microconstituents, and X-ray diffraction (XRD) for analysis of the crystalline phases. For measurement of mechanical properties, the discs will be tested by biaxial flexural strength test with monotonic load (n = 5). Using the mean value of strength previous obtained, the load profile will be defined to step-wise fatigue test (n = 18). The samples will be analyzed by oblique light transillumination during the fatigue test to identify the presence of radial cracks, which will be considered a failure. Then, fatigue failure load (FFL) data and number of failure cycles (CFF) will be recorded for statistical purposes. Descriptive statistical analysis will be performed to define the inferential statistical tests (5% significance level). The results will be discussed according to the relevant literature.