TY - JOUR
T1 - Aging resistant ZTA composite for dental applications
T2 - Microstructural, optical and mechanical characterization
AU - Benalcazar Jalkh, Ernesto Byron
AU - Monteiro, Kelli Nunes
AU - Cesar, Paulo Francisco
AU - Genova, Luis Antonio
AU - Bergamo, Edmara T.P.
AU - Lopes, Adolfo Coelho de Oliveira
AU - Lima, Erick
AU - Lisboa-Filho, Paulo Noronha
AU - Campos, Tiago Moreira Bastos
AU - Witek, Lukasz
AU - Coelho, Paulo G.
AU - Borges, Ana Flavia Sanches
AU - Bonfante, Estevam A.
N1 - Funding Information:
To São Paulo Research Foundation (FAPESP), grant # 2012/19078-7, EMU 2016/18818-8, and scholarships # 2018/03072-6; 2019/00452-5; 2019/08693-1; 2016/17793-1 and 2017/19362-0. To Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Grant # 304589/2017-9 and 434487/2018-0, to CAPES Financial Code 001. And to Secretaria Nacional de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT).
Funding Information:
To São Paulo Research Foundation ( FAPESP ), grant # 2012/19078-7 , EMU 2016/18818-8, and scholarships # 2018/03072-6; 2019/00452-5; 2019/08693-1; 2016/17793-1 and 2017/19362-0. To Conselho Nacional de Desenvolvimento Científico e Tecnológico ( CNPq ), Grant # 304589/2017-9 and 434487/2018-0 , to CAPES Financial Code 001. And to Secretaria Nacional de Educación Superior, Ciencia, Tecnología e Innovación ( SENESCY T).
Publisher Copyright:
© 2020 The Academy of Dental Materials
PY - 2020/9
Y1 - 2020/9
N2 - Objective: To synthesize a zirconia toughened alumina (ZTA) composite with 70% alumina reinforced by 30% zirconia for dental applications and to characterize its microstructure and optical properties for comparison with the isolated counterpart materials and a first-generation 3Y-TZP. Methods: Disc-shaped specimens were divided in four groups (n = 70/material): (1) 3YSB-E (first generation 3Y-TZP), (2) Zpex (second generation 3Y-TZP), (3) alumina, and (4) ZTA-Zpex 70/30. After synthesis, ceramic powders were pressed, and green-body samples sintered following a predetermined protocol. Specimens were polished to obtain a mirror surface finish. Apparent density was measured by Archimedes principle. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterize the crystalline content and microstructure. Reflectance tests were performed to determine the contrast-ratio (CR) and translucency-parameter (TP). Mechanical properties were assessed by biaxial flexural strength (BFS) test. All analyses were conducted before and after artificial aging (20 h, 134 °C, 2.2 bar). Optical parameters were evaluated through repeated-measures analysis of variance and Tukey tests (p < 0.05). BFS data were analyzed using Weibull statistics (95% CI). Results: High density values (95–99%) were found for all ceramic materials and SEM images exhibited a dense microstructure. While XRD patterns revealed the preservation of crystalline content in the ZTA composite, an increase in the monoclinic peak was observed for pure zirconias after aging. Significantly higher CR and lower TP values were observed for the ZTA composite, followed by alumina, 3YSB-E, and Zpex. The highest characteristic stress was recorded for 3YSB-E, followed by intermediate values between ZTA and Zpex, and the lowest for alumina. Aging affected the optical and mechanical properties of both zirconias, while remained stable for ZTA composite and alumina. Significance: The synthesis of experimental 70−30% ZTA composite was successful and its relevance for dental applications relies on its higher masking ability, aging resistance, and strength similar to zirconia.
AB - Objective: To synthesize a zirconia toughened alumina (ZTA) composite with 70% alumina reinforced by 30% zirconia for dental applications and to characterize its microstructure and optical properties for comparison with the isolated counterpart materials and a first-generation 3Y-TZP. Methods: Disc-shaped specimens were divided in four groups (n = 70/material): (1) 3YSB-E (first generation 3Y-TZP), (2) Zpex (second generation 3Y-TZP), (3) alumina, and (4) ZTA-Zpex 70/30. After synthesis, ceramic powders were pressed, and green-body samples sintered following a predetermined protocol. Specimens were polished to obtain a mirror surface finish. Apparent density was measured by Archimedes principle. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterize the crystalline content and microstructure. Reflectance tests were performed to determine the contrast-ratio (CR) and translucency-parameter (TP). Mechanical properties were assessed by biaxial flexural strength (BFS) test. All analyses were conducted before and after artificial aging (20 h, 134 °C, 2.2 bar). Optical parameters were evaluated through repeated-measures analysis of variance and Tukey tests (p < 0.05). BFS data were analyzed using Weibull statistics (95% CI). Results: High density values (95–99%) were found for all ceramic materials and SEM images exhibited a dense microstructure. While XRD patterns revealed the preservation of crystalline content in the ZTA composite, an increase in the monoclinic peak was observed for pure zirconias after aging. Significantly higher CR and lower TP values were observed for the ZTA composite, followed by alumina, 3YSB-E, and Zpex. The highest characteristic stress was recorded for 3YSB-E, followed by intermediate values between ZTA and Zpex, and the lowest for alumina. Aging affected the optical and mechanical properties of both zirconias, while remained stable for ZTA composite and alumina. Significance: The synthesis of experimental 70−30% ZTA composite was successful and its relevance for dental applications relies on its higher masking ability, aging resistance, and strength similar to zirconia.
KW - Composites
KW - Mechanical properties
KW - Microstructure
KW - Optical properties
KW - ZrO–AlO
KW - Zirconium
KW - Surface Properties
KW - Materials Testing
KW - Aluminum Oxide
KW - Ceramics
KW - Yttrium
KW - Dental Materials
UR - http://www.scopus.com/inward/record.url?scp=85086511837&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85086511837&partnerID=8YFLogxK
U2 - 10.1016/j.dental.2020.05.011
DO - 10.1016/j.dental.2020.05.011
M3 - Article
C2 - 32561117
AN - SCOPUS:85086511837
SN - 0109-5641
VL - 36
SP - 1190
EP - 1200
JO - Dental Materials
JF - Dental Materials
IS - 9
ER -