Preparation and characterization of nanoceramics of zirconia toughened alumina for use in Dentistry

• Grant number: 20/13627-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2021
• End date: July 31, 2021
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Luis Geraldo Vaz
• Grantee: Maria Letícia Verdi Emílio
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The most used material for implants is titanium and there are ceramic implants of zirconia partially stabilized with yttria (3Y-TZP) on the market. However, in the presence of liquid (body fluid), 3Y-TZP presents a transition from the tetragonal to the monoclinic crystalline phase, with a volume expansion of 4-5%, generating microcracks that with the loading process may result in fracture of the piece. Therefore, new materials should appear to minimize the effect of degradation in the presence of liquid. Zirconia toughened alumina (ZTA) is a technological alternative to the materials currently used to minimize the effect of 3Y-TZP degradation. The material tenacified with zirconia, with the addition of chromium oxide, was the alternative found by the femur head manufacturers to replace pure alumina and 3Y-TZP zirconia. However, this piece turns pink at the end of the heat treatment step for sintering, thus making its application as a prosthesis unfeasible to solve this problem of the project aims to study the replacement of chromium oxide by cerium oxide. The replacement of chromium oxide by cerium oxide will be analyzed in addition to the following comparisons: a) biaxial flexural strength, X-ray diffraction (XRD) to study the crystalline and present phases and quantification by the Rietveld method, and evaluation of the microstructure via scanning electron microscopy of the material after heat treatment. The experimental results will indicate whether cerium oxide was effective to adequate biaxial flexural strength, compatible with the commercial ZTA, in addition to the material having a white color that may be important for use as a prosthesis, thus indicating its potential use in Dentistry.