Study of doping with niobium oxide (Nb2O5) on tetragonal zirconia (3Y-TZP) to reduce hydrothermal degradation.

• Grant number: 22/07355-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2022
• End date: July 31, 2023
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Luis Geraldo Vaz
• Grantee: Leticia Matheus Rosa
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

In the presence of body fluid, polycrystalline tetragonal zirconia (3Y-TZP) presents a transformation from the tetragonal to the monoclinic crystalline phase, with a volumetric expansion (4-5%) with an increase in tension, which can generate microcracks from the loading process that will cause the material fracture, this effect was called "Low-Temperature Hydrothermal Degradation" (LTD), or aging. It is strategic to search for additives that reduce LTD in zirconia, enabling in vivo applications. High purity niobium oxide (Nb2O5) can reduce oxygen vacancies created by differences in ion charges (Zr4+ and Y3+) and degradation reduction. The project aims to dope the 3Y-TZP ceramic with Nb2O5 and evaluate its effect on hydrothermal degradation. To prove the effectiveness of the effect of niobium oxide will be carried, initially the preparation of compositions containing 3Y-TZP zirconia doped with different concentrations of niobium oxide, determination of the crystalline phases present before and after the LTD aging process of the 3Y-TZP doped with niobium oxide and verification of the LTD reduction, morphological evaluation of the polished and fractured surface, and Weibull statistics for the mechanical results.