Novel bilayered zirconia systems using recycled 3Y-TZP for dental applications

Author(s):Show less -

Benalcazar-Jalkh, Ernesto B. ; Campos, Tiago M. B. ; dos Santos, Claudinei ; Alves, Larissa M. M. ; Carvalho, Laura F. ; Bergamo, Edmara T. P. ; Tebcherani, Sergio M. ; Witek, Lukasz ; Coelho, Paulo G. ; Thim, Gilmar P. ; Yamaguchi, Satoshi ; Sousa, Edisa O. ; Marcolino, Giovana A. ; Bonfante, Estevam A.

• Document type: Journal article
• Source: Dental Materials; v. 41, n. 4, p. 12-pg., 2025-02-28.

Abstract

Objective To synthesize bilayer zirconia systems based on commercial or recycled 3Y-TZP obtained from non-milled remnants and to compare their optical and mechanical properties before and after aging. Methods Bilayer zirconia samples were fabricated using either recycled 3Y-TZP (3Y-R/4Y and 3Y-R/5Y) or commercial powders (3Y/4Y and 3Y/5Y). Microstructure and phase composition were analyzed using ScanningElectronMicroscopy (SEM) and X-Ray Diffraction (XRD). Optical and mechanical properties were assessed via reflectance and biaxial flexural strength tests (BFS), followed by fractographic analysis. Optical properties and BFS data were analyzed using two-way ANOVA and Tukey test, and Weibull statistics, respectively. Results Recycled powder exhibited particle sizes < 2.07 mu m. SEM micrographs depicted dense surfaces with largest grains in the 5Y, followed by recycled-3Y, 4Y, and commercial-3Y. XRD analysis revealed tetragonal peaks in commercial and recycled 3Y-TZPs, and tetragonal and cubic phases in the 4Y and 5Y surfaces. Aging induced significant phase transformation in 4Y (similar to 40 %), commercial- (58 %) and recycled-3Y (53 %), with no effect in 5Y surfaces. Commercial bilayers exhibited higher translucency and strength (similar to 1130 MPa) compared to recycled bilayers (similar to 935 MPa), with no significant differences within commercial, nor within recycled groups. Aging decreased contrast ratio for recycled groups and increased the strength of all groups. While all groups presented high reliability up to 500MPa, commercial bilayers outperformed recycled systems at 800-MPa. Significance The synthesis of bilayered systems using recycled-3Y was successful, resulting in high reliability in missions up to 500MPa. Bilayers based on commercial powder demonstrated superior translucency, strength, and reliability at 800MPa compared to their recycled counterparts. (AU)

• FAPESP's process: 21/07440-2 - Graduated glass infiltration in an ultra-translucent zirconia (5Y-PSZ): synthesis, processing and characterization of physical and mechanical properties
• Grantee: Larissa Marcia Martins Alves
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 22/05495-7 - Multi-user equipment approved in grant 21/06730-7: ElectroPuls E3000 All-Electric Dynamic Test Instrument, INSTRON
• Grantee: Estevam Augusto Bonfante
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 21/06730-7 - Towards sustainable zirconia recycled from milling waste and boosted by glass infiltration for restorative use, and of the development of strong, graded, and aging resistant multilayered zirconia blocks
• Grantee: Estevam Augusto Bonfante
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2
• FAPESP's process: 22/07733-2 - Physical and mechanical characterization of a bilayered zirconia system: influence of hydrothermal aging
• Grantee: Edisa de Oliveira Sousa
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 23/07289-8 - Influence of low temperature degradation on the wear resistance of recycled translucent zirconia
• Grantee: Larissa Marcia Martins Alves
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 22/07157-1 - Physical and mechanical characterization of a multilayered system using recycled zirconia
• Grantee: Ernesto Byron Benalcazar Jalkh
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/08693-1 - Experimental glass-infiltrated alumina-zirconia composites: characterization of microstructure, optical and mechanical properties.
• Grantee: Edmara Tatiely Pedroso Bergamo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 20/12874-9 - Infiltration graded by glass in an experimental composite based on whiskers of alumina and zircônia: development, microstructural characterization and optical and mechanical properties
• Grantee: Tiago Moreira Bastos Campos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 22/05496-3 - Multi-user equipment approved in grant 21/06730-7: Macrodurômetro VH1150 - Buehler
• Grantee: Estevam Augusto Bonfante
• Support Opportunities: Multi-user Equipment Program