Nanomechanical layer characterization of graded ATZ and ZTA composites

• Grant number: 21/08018-2
• Support type: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): January 17, 2022
• Effective date (End): January 16, 2023
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal researcher: Estevam Augusto Bonfante
• Grantee: Edmara Tatiely Pedroso Bergamo
• Supervisor abroad: Lukasz Witek
• Home Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Research place: New York University, United States
• Associated to the scholarship: 19/08693-1 - Experimental glass-infiltrated alumina-zirconia composites: characterization of microstructure, optical and mechanical properties., BP.PD

Abstract

Y-TZP presents the highest mechanical properties among all-ceramic systems available, however it is susceptible to low temperature degradation, which may compromise physical and mechanical properties of prostheses. This problematic was the motivation behind the Young Investigator Grant FAPESP #2012/19078-7 and has allowed the development of aging-resistant alumina-zirconia composites (ZTA and ATZ). Bioinspired glass infiltration in Y-TZP systems has demonstrated improved optical and mechanical properties, as well as adhesive bond strength. In this post-doctoral scholarship FAPESP #2019/08693-1, we proposed the glass infiltration of the developed ZTA and ATZ composites to boost their physical and mechanical properties, where a graded layer of 100 um and an increase of 250 MPa in flexural strength relative to non-infiltrated composites was observed. For comprehensive characterization of the graded materials, this BEPE proposal aims to further evaluate the mechanical properties of the layers and throughout their transitions of graded ZTA and ATZ composites using nanoscale indentation and finite element analysis (FEA). Experimental ZTA and ATZ disc-shaped specimens will be processed and infiltrated with silicate glasses. After sintering, the specimens will be sectioned and polished. Half of them will be subjected to hydrothermal aging. Nanoindentation will be performed by means of a Berkovich diamond pyramid probe at several regions of interest at intervals of 25 um to determine the gradient of hardness, elastic modulus, and residual stress of the glass, graded, and composite layers. The collected properties will be used to design a disc (ISO 6872:2015) for in silico non-linear dynamic FEA to be correlated with biaxial flexural strength data.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FARDIN, VINICIUS P.; BERGAMO, EDMARA T. P.; BORDIN, DIMORVAN; HIRATA, RONALDO; BONFANTE, ESTEVAM A.; BONFANTE, GERSON; COELHO, PAULO G.. Effect of different tightening protocols on the probability of survival of screw-retained implant-supported crowns. JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS, v. 126, FEB 2022. (21/08018-2, 11/16377-0, 16/18818-8, 13/20806-0, 14/22859-6, 21/06730-7, 11/23177-8)

VINICIUS PAVESI FARDIN; GERSON BONFANTE; PAULO G. COELHO; EDMARA T. P. BERGAMO; DIMORVAN BORDIN; MALVIN N. JANAL; NICK TOVAR; LUKASZ WITEK; ESTEVAM A. BONFANTE. Residual stress estimated by nanoindentation in pontics and abutments of veneered zirconia fixed dental prostheses. Journal of Applied Oral Science, v. 30, 2022-04-22. (21/08018-2, 14/22859-6, 19/08693-1, 12/19078-7, 11/23177-8, 21/06730-7, 13/20806-0, 16/18818-8, 11/16377-0)