EFFECT OF BIOMIMETIC GLASS GRADING ON THE MICROSTRUCTURAL, MECHANICAL, OPTICAL AND ADHESIVE CHARACTERISTICS OF AN ULTRA-TRANSLUCENT ZIRCONIA

• Grant number: 24/01634-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2025
• End date: February 29, 2028
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Marco Antonio Bottino
• Grantee: Karina Barbosa Souza
• 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

The objective of the work will be to structurally characterize and analyze the mechanical, optical and adhesive properties of 5Y-PSZ ultratranslucent zirconia infiltrated by biomimetic glass and the biomechanical behavior of 5Y-PSZ crowns with and without infiltration. Specimens in the shape of discs and crowns will be produced, depending on the test to be submitted, in 5Y-PSZ zirconia. In stage 1 of the project, structural characterization tests will be carried out using XRD, Raman spectroscopy, SEM-FEG and EDS. The translucency of the material will also be evaluated. To analyze the mechanical properties, measurements will be made of the elastic modulus, Vickers hardness, fracture toughness and biaxial flexural strength. In step 2, the bond strength analysis of 5Y-PSZ zirconia will be carried out with and without infiltration into the resin cement, also varying the surface treatments and the thermocycling factor (10,000 cycles, 5 °C and 55 °C baths, 30 seconds of immersion), by the microshear test (0.5 mm/min, 50 kgF). Subsequently, the specimens will have their failure modes classified under a stereomicroscope. In stage 3, fatigue resistance tests will be carried out on anatomical crowns of the upper first molar cemented on a previously prepared dental substrate, followed by fractographic analysis. Finite element analysis (FEA) and analysis of microcrack formation after fatigue using microtomography will also be carried out. The data will be analyzed qualitatively and quantitatively, depending on the test. Descriptive analyzes of the data will be carried out and then inferential statistical tests will be appropriately selected.