Jasna Cotič1, Peter Jevnikar2, Andraž Kocjan3, Tomaž Kosmač3. 1. Department of Prosthodontics, Faculty of Medicine, University of Ljubljana, Hrvatski trg 6, SI-1000, Ljubljana, Slovenia. Electronic address: jasna.cotic@mf.uni-lj.si. 2. Department of Prosthodontics, Faculty of Medicine, University of Ljubljana, Hrvatski trg 6, SI-1000, Ljubljana, Slovenia. 3. Engineering Ceramics Department, Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia.
Abstract
OBJECTIVES: This study was designed to explore the complex relationships between the sintering-temperature-dependent grain size, airborne-particle abrasion, ageing and strength of 3Y-TZP ceramics. METHODS: Biomedical grade 3Y-TZP powder was used to fabricate 180 discs. Half of them were sintered at 1400°C for 2h and half at 1500°C for 2h. A total of 18 groups of 10 were formed and subjected to the fully crossed experimental protocol of airborne-particle abrasion with Al2O3 at 2.5bar (no abrasion, 50μm, 110μm) and accelerated ageing at 134°C (no ageing, 12h, 48h). The relative amount of monoclinic phase was determined with XRD. The biaxial flexural strength was measured and statistically analyzed using the three-way ANOVA followed by predetermined contrasts and Tukey's HSD test (α=0.05). RESULTS: The low-temperature-sintered, fine-grained ceramic exhibited an excellent ageing resistance, while the high-temperature-sintered, coarse-grained ceramic experienced a higher surface strengthening and a substantially improved ageing resistance with respect to the airborne-particle abrasion. The overall performance of this material was superior. SIGNIFICANCE: Our results show that the sintering temperature has a minor effect on the flexural strength, but it plays a crucial role in the surface strengthening and the ageing behaviour of 3Y-TZP dental ceramics.
OBJECTIVES: This study was designed to explore the complex relationships between the sintering-temperature-dependent grain size, airborne-particle abrasion, ageing and strength of 3Y-TZP ceramics. METHODS: Biomedical grade 3Y-TZP powder was used to fabricate 180 discs. Half of them were sintered at 1400°C for 2h and half at 1500°C for 2h. A total of 18 groups of 10 were formed and subjected to the fully crossed experimental protocol of airborne-particle abrasion with Al2O3 at 2.5bar (no abrasion, 50μm, 110μm) and accelerated ageing at 134°C (no ageing, 12h, 48h). The relative amount of monoclinic phase was determined with XRD. The biaxial flexural strength was measured and statistically analyzed using the three-way ANOVA followed by predetermined contrasts and Tukey's HSD test (α=0.05). RESULTS: The low-temperature-sintered, fine-grained ceramic exhibited an excellent ageing resistance, while the high-temperature-sintered, coarse-grained ceramic experienced a higher surface strengthening and a substantially improved ageing resistance with respect to the airborne-particle abrasion. The overall performance of this material was superior. SIGNIFICANCE: Our results show that the sintering temperature has a minor effect on the flexural strength, but it plays a crucial role in the surface strengthening and the ageing behaviour of 3Y-TZP dental ceramics.
Authors: Stephanie Assimakopoulos Garófalo; Martin Wehner; Andreas Dohrn; Marin Dean Bilandžić; Christian Roos; Richard Johannes Wierichs; Hendrik Meyer-Lueckel; Ana Cecilia Corrêa Aranha; Marcella Esteves-Oliveira Journal: Clin Oral Investig Date: 2021-08-17 Impact factor: 3.606
Authors: Isabelle Denry; Maged Abdelaal; Deborah V Dawson; Julie A Holloway; John Robert Kelly Journal: J Prosthet Dent Date: 2020-08-15 Impact factor: 3.426